| contains 483 rules |
System Settings
[ref]groupContains rules that check correct system settings. |
| contains 287 rules |
Installing and Maintaining Software
[ref]groupThe following sections contain information on
security-relevant choices during the initial operating system
installation process and the setup of software
updates. |
| contains 49 rules |
System and Software Integrity
[ref]groupSystem and software integrity can be gained by installing antivirus, increasing
system encryption strength with FIPS, verifying installed software, enabling SELinux,
installing an Intrusion Prevention System, etc. However, installing or enabling integrity
checking tools cannot prevent intrusions, but they can detect that an intrusion
may have occurred. Requirements for integrity checking may be highly dependent on
the environment in which the system will be used. Snapshot-based approaches such
as AIDE may induce considerable overhead in the presence of frequent software updates. |
| contains 8 rules |
Software Integrity Checking
[ref]groupBoth the AIDE (Advanced Intrusion Detection Environment)
software and the RPM package management system provide
mechanisms for verifying the integrity of installed software.
AIDE uses snapshots of file metadata (such as hashes) and compares these
to current system files in order to detect changes.
The RPM package management system can conduct integrity
checks by comparing information in its metadata database with
files installed on the system. |
| contains 6 rules |
Verify Integrity with RPM
[ref]groupThe RPM package management system includes the ability
to verify the integrity of installed packages by comparing the
installed files with information about the files taken from the
package metadata stored in the RPM database. Although an attacker
could corrupt the RPM database (analogous to attacking the AIDE
database as described above), this check can still reveal
modification of important files. To list which files on the system differ from what is expected by the RPM database:
$ rpm -qVa
See the man page for rpm to see a complete explanation of each column. |
| contains 2 rules |
Verify and Correct Ownership with RPM
[ref]ruleThe RPM package management system can check file ownership permissions of installed software
packages, including many that are important to system security. After locating a file with
incorrect permissions, which can be found with:
rpm -Va | awk '{ if (substr($0,6,1)=="U" || substr($0,7,1)=="G") print $NF }'
run the following command to determine which package owns it:
$ rpm -qf FILENAME
Next, run the following command to reset its permissions to the correct values:
$ sudo rpm --restore PACKAGENAME Warning:
Profiles may require that specific files be owned by root while the default owner defined
by the vendor is different. Such files will be reported as a finding and need to be
evaluated according to your policy and deployment environment. Warning:
This rule can take a long time to perform the check and might consume a considerable
amount of resources depending on the number of packages present on the system. It is not a
problem in most cases, but especially systems with a large number of installed packages
can be affected. Rationale:Ownership of binaries and configuration files that is incorrect could allow an unauthorized
user to gain privileges that they should not have. The ownership set by the vendor should be
maintained. Any deviations from this baseline should be investigated. Identifiers:
CCE-91290-7 References:
1, 11, 12, 13, 14, 15, 16, 18, 3, 5, 6, 9, 5.10.4.1, APO01.06, APO11.04, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.04, DSS05.07, DSS06.02, MEA02.01, 3.3.8, 3.4.1, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.5.1, A.12.6.2, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R4.2, CIP-003-8 R6, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CM-6(d), CM-6(c), SI-7, SI-7(1), SI-7(6), AU-9(3), PR.AC-4, PR.DS-5, PR.IP-1, PR.PT-1, Req-11.5, SRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098, SRG-OS-000278-GPOS-00108, 6.1.1, SLES-15-900150000, 1409, 11.5.2 Remediation Shell script: (show)
| Complexity: | high |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ); then
# Declare array to hold set of RPM packages we need to correct permissions for
declare -A SETPERMS_RPM_DICT
# Create a list of files on the system having permissions different from what
# is expected by the RPM database
readarray -t FILES_WITH_INCORRECT_PERMS < <(rpm -Va --nofiledigest | awk '{ if (substr($0,6,1)=="U" || substr($0,7,1)=="G") print $NF }')
for FILE_PATH in "${FILES_WITH_INCORRECT_PERMS[@]}"
do
RPM_PACKAGE=$(rpm -qf "$FILE_PATH")
# Use an associative array to store packages as it's keys, not having to care about duplicates.
SETPERMS_RPM_DICT["$RPM_PACKAGE"]=1
done
# For each of the RPM packages left in the list -- reset its permissions to the
# correct values
for RPM_PACKAGE in "${!SETPERMS_RPM_DICT[@]}"
do
rpm --restore "${RPM_PACKAGE}"
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | high |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91290-7
- CJIS-5.10.4.1
- NIST-800-171-3.3.8
- NIST-800-171-3.4.1
- NIST-800-53-AU-9(3)
- NIST-800-53-CM-6(c)
- NIST-800-53-CM-6(d)
- NIST-800-53-SI-7
- NIST-800-53-SI-7(1)
- NIST-800-53-SI-7(6)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- high_complexity
- high_severity
- medium_disruption
- no_reboot_needed
- restrict_strategy
- rpm_verify_ownership
- name: Read list of files with incorrect ownership
ansible.builtin.command: rpm -Va --nodeps --nosignature --nofiledigest --nosize
--nomtime --nordev --nocaps --nolinkto --nomode
register: files_with_incorrect_ownership
failed_when: files_with_incorrect_ownership.rc > 1
changed_when: false
check_mode: false
when: not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline )
tags:
- CCE-91290-7
- CJIS-5.10.4.1
- NIST-800-171-3.3.8
- NIST-800-171-3.4.1
- NIST-800-53-AU-9(3)
- NIST-800-53-CM-6(c)
- NIST-800-53-CM-6(d)
- NIST-800-53-SI-7
- NIST-800-53-SI-7(1)
- NIST-800-53-SI-7(6)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- high_complexity
- high_severity
- medium_disruption
- no_reboot_needed
- restrict_strategy
- rpm_verify_ownership
- name: Create list of packages
ansible.builtin.command: rpm -qf "{{ item }}"
with_items: '{{ files_with_incorrect_ownership.stdout_lines | map(''regex_findall'',
''^[.]+[U|G]+.* (\/.*)'', ''\1'') | map(''join'') | select(''match'', ''(\/.*)'')
| list | unique }}'
register: list_of_packages
changed_when: false
check_mode: false
when:
- not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline )
- (files_with_incorrect_ownership.stdout_lines | length > 0)
tags:
- CCE-91290-7
- CJIS-5.10.4.1
- NIST-800-171-3.3.8
- NIST-800-171-3.4.1
- NIST-800-53-AU-9(3)
- NIST-800-53-CM-6(c)
- NIST-800-53-CM-6(d)
- NIST-800-53-SI-7
- NIST-800-53-SI-7(1)
- NIST-800-53-SI-7(6)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- high_complexity
- high_severity
- medium_disruption
- no_reboot_needed
- restrict_strategy
- rpm_verify_ownership
- name: Correct file ownership with RPM
ansible.builtin.command: rpm --restore '{{ item }}'
with_items: '{{ list_of_packages.results | map(attribute=''stdout_lines'') | list
| unique }}'
when:
- not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline )
- (files_with_incorrect_ownership.stdout_lines | length > 0)
tags:
- CCE-91290-7
- CJIS-5.10.4.1
- NIST-800-171-3.3.8
- NIST-800-171-3.4.1
- NIST-800-53-AU-9(3)
- NIST-800-53-CM-6(c)
- NIST-800-53-CM-6(d)
- NIST-800-53-SI-7
- NIST-800-53-SI-7(1)
- NIST-800-53-SI-7(6)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- high_complexity
- high_severity
- medium_disruption
- no_reboot_needed
- restrict_strategy
- rpm_verify_ownership
|
Verify and Correct File Permissions with RPM
[ref]ruleThe RPM package management system can check file access permissions of installed software
packages, including many that are important to system security. Verify that the file
permissions of system files and commands match vendor values. Check the file permissions with
the following command:
$ sudo rpm -Va | awk '{ if (substr($0,2,1)=="M") print $NF }'
Output indicates files that do not match vendor defaults.
After locating a file with incorrect permissions, run the following command to determine which
package owns it:
$ rpm -qf FILENAME
Next, run the following command to reset its permissions to the correct values:
$ sudo rpm --restore PACKAGENAME Warning:
Profiles may require that specific files have stricter file permissions than defined by
the vendor. Such files will be reported as a finding and need to be evaluated according to
your policy and deployment environment. Warning:
This rule can take a long time to perform the check and might consume a considerable
amount of resources depending on the number of packages present on the system. It is not a
problem in most cases, but especially systems with a large number of installed packages
can be affected. Rationale:Permissions on system binaries and configuration files that are too generous could allow an
unauthorized user to gain privileges that they should not have. The permissions set by the
vendor should be maintained. Any deviations from this baseline should be investigated. Identifiers:
CCE-85782-1 References:
1, 11, 12, 13, 14, 15, 16, 18, 3, 5, 6, 9, 5.10.4.1, APO01.06, APO11.04, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.04, DSS05.07, DSS06.02, MEA02.01, 3.3.8, 3.4.1, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.5.1, A.12.6.2, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R4.2, CIP-003-8 R6, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CM-6(d), CM-6(c), SI-7, SI-7(1), SI-7(6), AU-9(3), CM-6(a), PR.AC-4, PR.DS-5, PR.IP-1, PR.PT-1, Req-11.5, SRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098, SRG-OS-000258-GPOS-00099, SRG-OS-000278-GPOS-00108, 6.1.1, SLES-15-900150000, 1409, 11.5.2 Remediation Shell script: (show)
| Complexity: | high |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ); then
# Declare array to hold set of RPM packages we need to correct permissions for
declare -A SETPERMS_RPM_DICT
# Create a list of files on the system having permissions different from what
# is expected by the RPM database
readarray -t FILES_WITH_INCORRECT_PERMS < <(rpm -Va --nofiledigest | awk '{ if (substr($0,2,1)=="M") print $NF }')
for FILE_PATH in "${FILES_WITH_INCORRECT_PERMS[@]}"
do
# NOTE: some files maybe controlled by more then one package
readarray -t RPM_PACKAGES < <(rpm -qf "${FILE_PATH}")
for RPM_PACKAGE in "${RPM_PACKAGES[@]}"
do
# Use an associative array to store packages as it's keys, not having to care about duplicates.
SETPERMS_RPM_DICT["$RPM_PACKAGE"]=1
done
done
# For each of the RPM packages left in the list -- reset its permissions to the
# correct values
for RPM_PACKAGE in "${!SETPERMS_RPM_DICT[@]}"
do
rpm --restore "${RPM_PACKAGE}"
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | high |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85782-1
- CJIS-5.10.4.1
- NIST-800-171-3.3.8
- NIST-800-171-3.4.1
- NIST-800-53-AU-9(3)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(c)
- NIST-800-53-CM-6(d)
- NIST-800-53-SI-7
- NIST-800-53-SI-7(1)
- NIST-800-53-SI-7(6)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- high_complexity
- high_severity
- medium_disruption
- no_reboot_needed
- restrict_strategy
- rpm_verify_permissions
- name: Read list of files with incorrect permissions
ansible.builtin.command: rpm -Va --nodeps --nosignature --nofiledigest --nosize
--nomtime --nordev --nocaps --nolinkto --nouser --nogroup
register: files_with_incorrect_permissions
failed_when: files_with_incorrect_permissions.rc > 1
changed_when: false
check_mode: false
when: not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline )
tags:
- CCE-85782-1
- CJIS-5.10.4.1
- NIST-800-171-3.3.8
- NIST-800-171-3.4.1
- NIST-800-53-AU-9(3)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(c)
- NIST-800-53-CM-6(d)
- NIST-800-53-SI-7
- NIST-800-53-SI-7(1)
- NIST-800-53-SI-7(6)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- high_complexity
- high_severity
- medium_disruption
- no_reboot_needed
- restrict_strategy
- rpm_verify_permissions
- name: Create list of packages
ansible.builtin.command: rpm -qf "{{ item }}"
with_items: '{{ files_with_incorrect_permissions.stdout_lines | map(''regex_findall'',
''^[.]+[M]+.* (\/.*)'', ''\1'') | map(''join'') | select(''match'', ''(\/.*)'')
| list | unique }}'
register: list_of_packages
changed_when: false
check_mode: false
when:
- not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline )
- (files_with_incorrect_permissions.stdout_lines | length > 0)
tags:
- CCE-85782-1
- CJIS-5.10.4.1
- NIST-800-171-3.3.8
- NIST-800-171-3.4.1
- NIST-800-53-AU-9(3)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(c)
- NIST-800-53-CM-6(d)
- NIST-800-53-SI-7
- NIST-800-53-SI-7(1)
- NIST-800-53-SI-7(6)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- high_complexity
- high_severity
- medium_disruption
- no_reboot_needed
- restrict_strategy
- rpm_verify_permissions
- name: Correct file permissions with RPM
ansible.builtin.command: rpm --restore '{{ item }}'
with_items: '{{ list_of_packages.results | map(attribute=''stdout_lines'') | list
| unique }}'
when:
- not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline )
- (files_with_incorrect_permissions.stdout_lines | length > 0)
tags:
- CCE-85782-1
- CJIS-5.10.4.1
- NIST-800-171-3.3.8
- NIST-800-171-3.4.1
- NIST-800-53-AU-9(3)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(c)
- NIST-800-53-CM-6(d)
- NIST-800-53-SI-7
- NIST-800-53-SI-7(1)
- NIST-800-53-SI-7(6)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- high_complexity
- high_severity
- medium_disruption
- no_reboot_needed
- restrict_strategy
- rpm_verify_permissions
|
Verify Integrity with AIDE
[ref]groupAIDE conducts integrity checks by comparing information about
files with previously-gathered information. Ideally, the AIDE database is
created immediately after initial system configuration, and then again after any
software update. AIDE is highly configurable, with further configuration
information located in /usr/share/doc/aide-VERSION. |
| contains 4 rules |
Install AIDE
[ref]ruleThe aide package can be installed with the following command:
$ sudo zypper install aide Rationale:The AIDE package must be installed if it is to be available for integrity checking. Identifiers:
CCE-83289-9 References:
1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9, 5.10.1.3, APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.7, A.15.2.1, A.8.2.3, CM-6(a), DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3, Req-11.5, SRG-OS-000445-GPOS-00199, SLES-15-010419, 1.4.1, R76, R79, SLES-15-750150015, 1034, 1288, 1341, 1417, 11.5.2, SV-255922r958794_rule Remediation script: (show)
[[packages]]
name = "aide"
version = "*"
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_aide
class install_aide {
package { 'aide':
ensure => 'installed',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
zypper install -y "aide"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83289-9
- CJIS-5.10.1.3
- DISA-STIG-SLES-15-010419
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_aide_installed
- name: Ensure aide is installed
ansible.builtin.package:
name: aide
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83289-9
- CJIS-5.10.1.3
- DISA-STIG-SLES-15-010419
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_aide_installed
|
Build and Test AIDE Database
[ref]ruleRun the following command to generate a new database:
$ sudo /usr/bin/aide --init
By default, the database will be written to the file
/var/lib/aide/aide.db.new.
Storing the database, the configuration file /etc/aide.conf, and the binary
/usr/bin/aide
(or hashes of these files), in a secure location (such as on read-only media) provides additional assurance about their integrity.
The newly-generated database can be installed as follows:
$ sudo cp /var/lib/aide/aide.db.new /var/lib/aide/aide.db
To initiate a manual check, run the following command:
$ sudo /usr/bin/aide --check
If this check produces any unexpected output, investigate.Warning:
In RHEL Image Mode (bootc) systems, the AIDE database must be regenerated after each system update.
Image Mode systems receive updates through new container images that may include modified files.
After applying system updates, run the following commands to regenerate the AIDE database:
$ sudo /usr/bin/aide --init
Then replace the existing database:
$ sudo cp /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz
Failure to regenerate the AIDE database after updates will result in false positive alerts
for legitimate system changes introduced by the update process. Rationale:For AIDE to be effective, an initial database of "known-good" information about files
must be captured and it should be able to be verified against the installed files. Identifiers:
CCE-85787-0 References:
1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9, 5.10.1.3, APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.7, A.15.2.1, A.8.2.3, CM-6(a), DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3, Req-11.5, SRG-OS-000445-GPOS-00199, SLES-15-010419, 1.4.1, R76, R79, SLES-15-750150015, 11.5.2, SV-255922r958794_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
zypper -q --no-remote ref
zypper install -y "aide"
/usr/bin/aide --init
/bin/cp -p /var/lib/aide/aide.db.new /var/lib/aide/aide.db
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85787-0
- CJIS-5.10.1.3
- DISA-STIG-SLES-15-010419
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_build_database
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Build and Test AIDE Database - Ensure Repositories Are Updated
ansible.builtin.command: zypper -q --no-remote ref
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85787-0
- CJIS-5.10.1.3
- DISA-STIG-SLES-15-010419
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_build_database
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Build and Test AIDE Database - Ensure AIDE Is Installed
ansible.builtin.package:
name: '{{ item }}'
state: present
with_items:
- aide
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85787-0
- CJIS-5.10.1.3
- DISA-STIG-SLES-15-010419
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_build_database
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Build and Test AIDE Database - Check Whether the Stock AIDE Database Exists
ansible.builtin.stat:
path: /var/lib/aide/aide.db.new
register: aide_database_stat
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85787-0
- CJIS-5.10.1.3
- DISA-STIG-SLES-15-010419
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_build_database
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Build and Test AIDE Database - Build and Test AIDE Database
ansible.builtin.command: /usr/bin/aide --init
changed_when: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not (aide_database_stat.stat.exists is defined and aide_database_stat.stat.exists)
register: aide_database_init
tags:
- CCE-85787-0
- CJIS-5.10.1.3
- DISA-STIG-SLES-15-010419
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_build_database
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Build and Test AIDE Database - Stage AIDE Database
ansible.builtin.copy:
src: /var/lib/aide/aide.db.new
dest: /var/lib/aide/aide.db
backup: true
remote_src: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- aide_database_init is changed
- not ansible_check_mode
tags:
- CCE-85787-0
- CJIS-5.10.1.3
- DISA-STIG-SLES-15-010419
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_build_database
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Configure AIDE to Verify the Audit Tools
[ref]ruleThe operating system file integrity tool must be configured to protect the integrity of the audit tools. Rationale:Protecting the integrity of the tools used for auditing purposes is a
critical step toward ensuring the integrity of audit information. Audit
information includes all information (e.g., audit records, audit settings,
and audit reports) needed to successfully audit information system
activity.
Audit tools include but are not limited to vendor-provided and open-source
audit tools needed to successfully view and manipulate audit information
system activity and records. Audit tools include custom queries and report
generators.
It is not uncommon for attackers to replace the audit tools or inject code
into the existing tools to provide the capability to hide or erase system
activity from the audit logs.
To address this risk, audit tools must be cryptographically signed to
provide the capability to identify when the audit tools have been modified,
manipulated, or replaced. An example is a checksum hash of the file or
files. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
zypper install -y "aide"
if grep -i -E '^.*(/usr)?/sbin/auditctl.*$' /etc/aide.conf; then
sed -i -r "s#.*(/usr)?/sbin/auditctl.*#/usr/sbin/auditctl p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
else
echo "/usr/sbin/auditctl p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
fi
if grep -i -E '^.*(/usr)?/sbin/auditd.*$' /etc/aide.conf; then
sed -i -r "s#.*(/usr)?/sbin/auditd.*#/usr/sbin/auditd p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
else
echo "/usr/sbin/auditd p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
fi
if grep -i -E '^.*(/usr)?/sbin/ausearch.*$' /etc/aide.conf; then
sed -i -r "s#.*(/usr)?/sbin/ausearch.*#/usr/sbin/ausearch p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
else
echo "/usr/sbin/ausearch p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
fi
if grep -i -E '^.*(/usr)?/sbin/aureport.*$' /etc/aide.conf; then
sed -i -r "s#.*(/usr)?/sbin/aureport.*#/usr/sbin/aureport p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
else
echo "/usr/sbin/aureport p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
fi
if grep -i -E '^.*(/usr)?/sbin/autrace.*$' /etc/aide.conf; then
sed -i -r "s#.*(/usr)?/sbin/autrace.*#/usr/sbin/autrace p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
else
echo "/usr/sbin/autrace p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
fi
if grep -i -E '^.*(/usr)?/sbin/augenrules.*$' /etc/aide.conf; then
sed -i -r "s#.*(/usr)?/sbin/augenrules.*#/usr/sbin/augenrules p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
else
echo "/usr/sbin/augenrules p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
fi
if grep -i -E '^.*(/usr)?/sbin/audispd.*$' /etc/aide.conf; then
sed -i -r "s#.*(/usr)?/sbin/audispd.*#/usr/sbin/audispd p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
else
echo "/usr/sbin/audispd p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85610-4
- DISA-STIG-SLES-15-030630
- NIST-800-53-AU-9(3)
- NIST-800-53-AU-9(3).1
- aide_check_audit_tools
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure AIDE to Verify the Audit Tools - Gather List of Packages
tags:
- CCE-85610-4
- DISA-STIG-SLES-15-030630
- NIST-800-53-AU-9(3)
- NIST-800-53-AU-9(3).1
- aide_check_audit_tools
- aide_check_audit_tools
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
ansible.builtin.package_facts:
manager: auto
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- name: Ensure aide is installed
ansible.builtin.package:
name: '{{ item }}'
state: present
with_items:
- aide
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85610-4
- DISA-STIG-SLES-15-030630
- NIST-800-53-AU-9(3)
- NIST-800-53-AU-9(3).1
- aide_check_audit_tools
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure AIDE to Verify the Audit Tools - Gather the package facts
ansible.builtin.package_facts:
manager: auto
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85610-4
- DISA-STIG-SLES-15-030630
- NIST-800-53-AU-9(3)
- NIST-800-53-AU-9(3).1
- aide_check_audit_tools
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Set audit_tools fact
ansible.builtin.set_fact:
audit_tools:
- /usr/sbin/audispd
- /usr/sbin/auditctl
- /usr/sbin/auditd
- /usr/sbin/augenrules
- /usr/sbin/aureport
- /usr/sbin/ausearch
- /usr/sbin/autrace
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85610-4
- DISA-STIG-SLES-15-030630
- NIST-800-53-AU-9(3)
- NIST-800-53-AU-9(3).1
- aide_check_audit_tools
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure existing AIDE configuration for audit tools are correct
ansible.builtin.lineinfile:
path: /etc/aide.conf
regexp: ^{{ item }}\s
line: '{{ item }} p+i+n+u+g+s+b+acl+selinux+xattrs+sha512'
create: true
with_items: '{{ audit_tools }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"aide" in ansible_facts.packages'
tags:
- CCE-85610-4
- DISA-STIG-SLES-15-030630
- NIST-800-53-AU-9(3)
- NIST-800-53-AU-9(3).1
- aide_check_audit_tools
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure AIDE to properly protect audit tools
ansible.builtin.lineinfile:
path: /etc/aide.conf
line: '{{ item }} p+i+n+u+g+s+b+acl+selinux+xattrs+sha512'
create: true
with_items: '{{ audit_tools }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"aide" in ansible_facts.packages'
tags:
- CCE-85610-4
- DISA-STIG-SLES-15-030630
- NIST-800-53-AU-9(3)
- NIST-800-53-AU-9(3).1
- aide_check_audit_tools
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Configure Systemd Timer Execution of AIDE
[ref]ruleAt a minimum, AIDE should be configured to run a weekly scan.
To implement a systemd service and a timer unit to run the service periodically:
For example, if a systemd timer is expected to be started every day at 5AM
OnCalendar=*-*-* 05:00:0 [Timer] section in the timer unit and
a Unit section starting the AIDE check service unit should be referred.Rationale:AIDE provides a means to check if unauthorized changes are made to the system.
AIDE itself does not setup a periodic execution, so in order to detect unauthorized
changes a systemd service to run the check and a systemd timer to take care
of periodical execution of that systemd service should be defined. Identifiers:
CCE-92516-4 References:
1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9, 5.10.1.3, APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.7, A.15.2.1, A.8.2.3, SI-6(d), DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3, Req-11.5, SRG-OS-000363-GPOS-00150, SRG-OS-000446-GPOS-00200, SRG-OS-000447-GPOS-00201, SLES-15-010570, 1.4.2, R76, SLES-15-750150030, 11.5.2, SV-234864r958948_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { ( rpm --quiet -q aide && rpm --quiet -q systemd ); }; then
zypper install -y "aide"
# create unit file for periodic aide database check
cat > /etc/systemd/system/aidecheck.service <<EOF
[Unit]
Description=Aide Check
[Service]
Type=simple
ExecStart=/usr/bin/aide --check
[Install]
WantedBy=multi-user.target
EOF
# create unit file for the aide check timer
cat > /etc/systemd/system/aidecheck.timer <<EOF
[Unit]
Description=Aide check every day at 5AM
[Timer]
OnCalendar=*-*-* 05:00:00
Unit=aidecheck.service
[Install]
WantedBy=multi-user.target
EOF
# setup service unit files attributes
chown root:root /etc/systemd/system/aidecheck.*
chmod 0644 /etc/systemd/system/aidecheck.*
# enable the aide related services
systemctl daemon-reload
systemctl enable aidecheck.service
systemctl enable aidecheck.timer
if [[ $(systemctl is-system-running) != "offline" ]]; then
systemctl start aidecheck.timer
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92516-4
- CJIS-5.10.1.3
- DISA-STIG-SLES-15-010570
- NIST-800-53-SI-6(d)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_periodic_checking_systemd_timer
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Configure Systemd Timer Execution of AIDE - Define AIDE Periodic Check Service
ansible.builtin.blockinfile:
create: true
dest: /etc/systemd/system/aidecheck.service
owner: root
group: root
mode: '0644'
block: |
[Unit]
Description=Aide Check
[Service]
Type=simple
ExecStart=/usr/bin/aide --check
[Install]
WantedBy=multi-user.target
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( "aide" in ansible_facts.packages and "systemd" in ansible_facts.packages )
tags:
- CCE-92516-4
- CJIS-5.10.1.3
- DISA-STIG-SLES-15-010570
- NIST-800-53-SI-6(d)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_periodic_checking_systemd_timer
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Configure Systemd Timer Execution of AIDE - Define AIDE Periodic Check Service
Timer
ansible.builtin.blockinfile:
create: true
dest: /etc/systemd/system/aidecheck.timer
owner: root
group: root
mode: '0644'
block: |
[Unit]
Description=Aide check every day at 5AM
[Timer]
OnCalendar=*-*-* 05:00:00
Unit=aidecheck.service
[Install]
WantedBy=multi-user.target
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( "aide" in ansible_facts.packages and "systemd" in ansible_facts.packages )
tags:
- CCE-92516-4
- CJIS-5.10.1.3
- DISA-STIG-SLES-15-010570
- NIST-800-53-SI-6(d)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_periodic_checking_systemd_timer
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Configure Systemd Timer Execution of AIDE - Ensure AIDE Service is Enabled
ansible.builtin.systemd:
name: aidecheck.service
enabled: true
daemon_reload: true
masked: false
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( "aide" in ansible_facts.packages and "systemd" in ansible_facts.packages )
tags:
- CCE-92516-4
- CJIS-5.10.1.3
- DISA-STIG-SLES-15-010570
- NIST-800-53-SI-6(d)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_periodic_checking_systemd_timer
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Configure Systemd Timer Execution of AIDE - Ensure AIDE Service Timer is Enabled
ansible.builtin.systemd:
name: aidecheck.timer
state: started
enabled: true
daemon_reload: true
masked: false
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( "aide" in ansible_facts.packages and "systemd" in ansible_facts.packages )
tags:
- CCE-92516-4
- CJIS-5.10.1.3
- DISA-STIG-SLES-15-010570
- NIST-800-53-SI-6(d)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_periodic_checking_systemd_timer
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
System Cryptographic Policies
[ref]groupLinux has the capability to centrally configure cryptographic polices. The command
update-crypto-policies is used to set the policy applicable for the various
cryptographic back-ends, such as SSL/TLS libraries. The configured cryptographic
policies will be the default policy used by these backends unless the application
user configures them otherwise. When the system has been configured to use the
centralized cryptographic policies, the administrator is assured that any application
that utilizes the supported backends will follow a policy that adheres to the
configured profile.
Currently the supported backends are:
- GnuTLS library
- OpenSSL library
- NSS library
- OpenJDK
- Libkrb5
- BIND
- OpenSSH
Applications and languages which rely on any of these backends will follow the
system policies as well. Examples are apache httpd, nginx, php, and others. |
| contains 2 rules |
Configure System Cryptography Policy
[ref]ruleTo configure the system cryptography policy to use ciphers only from the DEFAULT:NO-SHA1
policy, run the following command:
$ sudo update-crypto-policies --set DEFAULT:NO-SHA1
The rule checks if settings for selected crypto policy are configured as expected. Configuration files in the /etc/crypto-policies/back-ends are either symlinks to correct files provided by Crypto-policies package or they are regular files in case crypto policy customizations are applied.
Crypto policies may be customized by crypto policy modules, in which case it is delimited from the base policy using a colon.Warning:
The system needs to be rebooted for these changes to take effect. Warning:
System Crypto Modules must be provided by a vendor that undergoes
FIPS-140 certifications.
FIPS-140 is applicable to all Federal agencies that use
cryptographic-based security systems to protect sensitive information
in computer and telecommunication systems (including voice systems) as
defined in Section 5131 of the Information Technology Management Reform
Act of 1996, Public Law 104-106. This standard shall be used in
designing and implementing cryptographic modules that Federal
departments and agencies operate or are operated for them under
contract. See https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.140-2.pdf
To meet this, the system has to have cryptographic software provided by
a vendor that has undergone this certification. This means providing
documentation, test results, design information, and independent third
party review by an accredited lab. While open source software is
capable of meeting this, it does not meet FIPS-140 unless the vendor
submits to this process. Rationale:Centralized cryptographic policies simplify applying secure ciphers across an operating system and
the applications that run on that operating system. Use of weak or untested encryption algorithms
undermines the purposes of utilizing encryption to protect data. Identifiers:
CCE-85776-3 References:
164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.312(e)(1), 164.312(e)(2)(ii), CIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1, AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13, SC-12(2), SC-12(3), FCS_COP.1(1), FCS_COP.1(2), FCS_COP.1(3), FCS_COP.1(4), FCS_CKM.1, FCS_CKM.2, FCS_TLSC_EXT.1, SRG-OS-000396-GPOS-00176, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174, SLES-15-150900015, SLES-15-150900030, 1446, 2.2.7, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
var_system_crypto_policy='DEFAULT:NO-SHA1'
zypper install -y "crypto-policies-scripts"
stderr_of_call=$(update-crypto-policies --set ${var_system_crypto_policy} 2>&1 > /dev/null)
rc=$?
if test "$rc" = 127; then
echo "$stderr_of_call" >&2
echo "Make sure that the script is installed on the remediated system." >&2
echo "See output of the 'dnf provides update-crypto-policies' command" >&2
echo "to see what package to (re)install" >&2
false # end with an error code
elif test "$rc" != 0; then
echo "Error invoking the update-crypto-policies script: $stderr_of_call" >&2
false # end with an error code
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: XCCDF Value var_system_crypto_policy # promote to variable
set_fact:
var_system_crypto_policy: !!str DEFAULT:NO-SHA1
tags:
- always
- name: Configure System Cryptography Policy - Ensure crypto-policies-scripts package
installed
become: true
ansible.builtin.package:
name: crypto-policies-scripts
state: present
tags:
- CCE-85776-3
- NIST-800-53-AC-17(2)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-MA-4(6)
- NIST-800-53-SC-12(2)
- NIST-800-53-SC-12(3)
- NIST-800-53-SC-13
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.7
- configure_crypto_policy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
- name: Configure System Cryptography Policy - Check current crypto policy (runtime)
ansible.builtin.command: /usr/bin/update-crypto-policies --show
register: current_crypto_policy
changed_when: false
failed_when: false
check_mode: false
tags:
- CCE-85776-3
- NIST-800-53-AC-17(2)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-MA-4(6)
- NIST-800-53-SC-12(2)
- NIST-800-53-SC-12(3)
- NIST-800-53-SC-13
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.7
- configure_crypto_policy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
- name: Configure System Cryptography Policy - Get mtime of /etc/crypto-policies/config
ansible.builtin.stat:
path: /etc/crypto-policies/config
register: config_file_stat
changed_when: false
failed_when: false
check_mode: false
tags:
- CCE-85776-3
- NIST-800-53-AC-17(2)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-MA-4(6)
- NIST-800-53-SC-12(2)
- NIST-800-53-SC-12(3)
- NIST-800-53-SC-13
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.7
- configure_crypto_policy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
- name: Configure System Cryptography Policy - Get mtime of /etc/crypto-policies/state/current
ansible.builtin.stat:
path: /etc/crypto-policies/state/current
register: current_file_stat
changed_when: false
failed_when: false
check_mode: false
tags:
- CCE-85776-3
- NIST-800-53-AC-17(2)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-MA-4(6)
- NIST-800-53-SC-12(2)
- NIST-800-53-SC-12(3)
- NIST-800-53-SC-13
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.7
- configure_crypto_policy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
- name: Configure System Cryptography Policy - Check existence of /etc/crypto-policies/back-ends/nss.config
ansible.builtin.stat:
path: /etc/crypto-policies/back-ends/nss.config
register: nss_config_stat
changed_when: false
failed_when: false
check_mode: false
tags:
- CCE-85776-3
- NIST-800-53-AC-17(2)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-MA-4(6)
- NIST-800-53-SC-12(2)
- NIST-800-53-SC-12(3)
- NIST-800-53-SC-13
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.7
- configure_crypto_policy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
- name: Configure System Cryptography Policy - Verify that Crypto Policy is Set (runtime)
ansible.builtin.command: /usr/bin/update-crypto-policies --set {{ var_system_crypto_policy
}}
when: (current_crypto_policy.stdout.strip() != var_system_crypto_policy) or (config_file_stat.stat.exists
and current_file_stat.stat.exists and config_file_stat.stat.mtime > current_file_stat.stat.mtime)
or (not nss_config_stat.stat.exists)
tags:
- CCE-85776-3
- NIST-800-53-AC-17(2)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-MA-4(6)
- NIST-800-53-SC-12(2)
- NIST-800-53-SC-12(3)
- NIST-800-53-SC-13
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.7
- configure_crypto_policy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
|
Configure SSH to use System Crypto Policy
[ref]ruleCrypto Policies provide a centralized control over crypto algorithms usage of many packages.
SSH is supported by crypto policy, but the SSH configuration may be
set up to ignore it.
To check that Crypto Policies settings are configured correctly, ensure that
the CRYPTO_POLICY variable is either commented or not set at all
in the /etc/sysconfig/sshd. Rationale:Overriding the system crypto policy makes the behavior of the SSH service violate expectations,
and makes system configuration more fragmented. Identifiers:
CCE-85795-3 References:
164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.312(e)(1), 164.312(e)(2)(ii), CIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1, AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13, FCS_SSH_EXT.1, FCS_SSHS_EXT.1, FCS_SSHC_EXT.1, Req-2.2, SRG-OS-000250-GPOS-00093, SLES-15-150900045, 0418, 2.2.7, 2.2 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SSH_CONF="/etc/sysconfig/sshd"
sed -i "/^\s*CRYPTO_POLICY.*$/Id" $SSH_CONF
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85795-3
- NIST-800-53-AC-17(2)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-MA-4(6)
- NIST-800-53-SC-13
- PCI-DSS-Req-2.2
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.7
- configure_ssh_crypto_policy
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- name: Configure SSH to use System Crypto Policy
ansible.builtin.lineinfile:
dest: /etc/sysconfig/sshd
state: absent
regexp: (?i)^\s*CRYPTO_POLICY.*$
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85795-3
- NIST-800-53-AC-17(2)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-MA-4(6)
- NIST-800-53-SC-13
- PCI-DSS-Req-2.2
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.7
- configure_ssh_crypto_policy
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
|
Disk Partitioning
[ref]groupTo ensure separation and protection of data, there
are top-level system directories which should be placed on their
own physical partition or logical volume. The installer's default
partitioning scheme creates separate logical volumes for
/, /boot, and swap.
- If starting with any of the default layouts, check the box to
\"Review and modify partitioning.\" This allows for the easy creation
of additional logical volumes inside the volume group already
created, though it may require making
/'s logical volume smaller to
create space. In general, using logical volumes is preferable to
using partitions because they can be more easily adjusted
later. - If creating a custom layout, create the partitions mentioned in
the previous paragraph (which the installer will require anyway),
as well as separate ones described in the following sections.
If a system has already been installed, and the default
partitioning
scheme was used, it is possible but nontrivial to
modify it to create separate logical volumes for the directories
listed above. The Logical Volume Manager (LVM) makes this possible. |
| contains 8 rules |
Encrypt Partitions
[ref]ruleSUSE Linux Enterprise 15 natively supports partition encryption through the
Linux Unified Key Setup-on-disk-format (LUKS) technology. The easiest way to
encrypt a partition is during installation time.
For manual installations, select the Encrypt checkbox during
partition creation to encrypt the partition. When this
option is selected the system will prompt for a passphrase to use in
decrypting the partition. The passphrase will subsequently need to be entered manually
every time the system boots.
Detailed information on encrypting partitions using LUKS or LUKS ciphers can be found on
the SUSE Linux Enterprise 15 Documentation web site:
https://documentation.suse.com/sles/15-SP2/html/SLES-all/cha-security-cryptofs.html
. Rationale:The risk of a system's physical compromise, particularly mobile systems such as
laptops, places its data at risk of compromise. Encrypting this data mitigates
the risk of its loss if the system is lost. Identifiers:
CCE-85719-3 References:
13, 14, APO01.06, BAI02.01, BAI06.01, DSS04.07, DSS05.03, DSS05.04, DSS05.07, DSS06.02, DSS06.06, 3.13.16, 164.308(a)(1)(ii)(D), 164.308(b)(1), 164.310(d), 164.312(a)(1), 164.312(a)(2)(iii), 164.312(a)(2)(iv), 164.312(b), 164.312(c), 164.314(b)(2)(i), 164.312(d), SR 3.4, SR 4.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R4.2, CIP-007-3 R5.1, SC-28, SC-28.1, PR.DS-1, PR.DS-5, SRG-OS-000405-GPOS-00184, SRG-OS-000185-GPOS-00079, SRG-OS-000404-GPOS-00183, SLES-15-010330, SLES-15-150150540, SV-234831r1009558_rule |
Ensure /dev/shm is configured
[ref]ruleThe /dev/shm is a traditional shared memory concept.
One program will create a memory portion, which other processes
(if permitted) can access. If /dev/shm is not configured,
tmpfs will be mounted to /dev/shm by systemd. Warning:
This rule does not have a remediation.
It is expected that this will be managed by systemd and will be a tmpfs partition. Rationale:Any user can upload and execute files inside the /dev/shm similar to
the /tmp partition. Configuring /dev/shm allows an administrator
to set the noexec option on the mount, making /dev/shm useless for an attacker to
install executable code. It would also prevent an attacker from establishing a
hardlink to a system setuid program and wait for it to be updated. Once the program
was updated, the hardlink would be broken and the attacker would have his own copy
of the program. If the program happened to have a security vulnerability, the attacker
could continue to exploit the known flaw. |
Ensure /home Located On Separate Partition
[ref]ruleIf user home directories will be stored locally, create a separate partition
for /home at installation time (or migrate it later using LVM). If
/home will be mounted from another system such as an NFS server, then
creating a separate partition is not necessary at installation time, and the
mountpoint can instead be configured later. Rationale:Ensuring that /home is mounted on its own partition enables the
setting of more restrictive mount options, and also helps ensure that
users cannot trivially fill partitions used for log or audit data storage. Identifiers:
CCE-85639-3 References:
12, 15, 8, APO13.01, DSS05.02, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.13.1.1, A.13.2.1, A.14.1.3, CM-6(a), SC-5(2), PR.PT-4, SRG-OS-000480-GPOS-00227, SLES-15-040200, 1.1.17, R28, SLES-15-150150270, SV-235004r991589_rule |
Ensure /tmp Located On Separate Partition
[ref]ruleThe /tmp directory is a world-writable directory used
for temporary file storage. Ensure it has its own partition or
logical volume at installation time, or migrate it using LVM. Rationale:The /tmp partition is used as temporary storage by many programs.
Placing /tmp in its own partition enables the setting of more
restrictive mount options, which can help protect programs which use it. Identifiers:
CCE-91179-2 References:
12, 15, 8, APO13.01, DSS05.02, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.13.1.1, A.13.2.1, A.14.1.3, CM-6(a), SC-5(2), PR.PT-4, SRG-OS-000480-GPOS-00227, 1.1.2, SLES-15-150150150 |
Ensure /var Located On Separate Partition
[ref]ruleThe /var directory is used by daemons and other system
services to store frequently-changing data. Ensure that /var has its own partition
or logical volume at installation time, or migrate it using LVM. Rationale:Ensuring that /var is mounted on its own partition enables the
setting of more restrictive mount options. This helps protect
system services such as daemons or other programs which use it.
It is not uncommon for the /var directory to contain
world-writable directories installed by other software packages. Identifiers:
CCE-85640-1 References:
12, 15, 8, APO13.01, DSS05.02, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.13.1.1, A.13.2.1, A.14.1.3, CM-6(a), SC-5(2), PR.PT-4, SRG-OS-000480-GPOS-00227, SLES-15-040210, 1.1.10, R28, SLES-15-150150315, SV-235005r991589_rule |
Ensure /var/log Located On Separate Partition
[ref]ruleSystem logs are stored in the /var/log directory.
Ensure that /var/log has its own partition or logical
volume at installation time, or migrate it using LVM. Rationale:Placing /var/log in its own partition
enables better separation between log files
and other files in /var/. Identifiers:
CCE-91181-8 References:
1, 12, 14, 15, 16, 3, 5, 6, 8, APO11.04, APO13.01, BAI03.05, DSS05.02, DSS05.04, DSS05.07, MEA02.01, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, CIP-007-3 R6.5, CM-6(a), AU-4, SC-5(2), PR.PT-1, PR.PT-4, SRG-OS-000480-GPOS-00227, 1.1.15, R28, SLES-15-150150420 |
Ensure /var/log/audit Located On Separate Partition
[ref]ruleAudit logs are stored in the /var/log/audit directory.
Ensure that /var/log/audit has its own partition or logical
volume at installation time, or migrate it using LVM.
Make absolutely certain that it is large enough to store all
audit logs that will be created by the auditing daemon. Rationale:Placing /var/log/audit in its own partition
enables better separation between audit files
and other files, and helps ensure that
auditing cannot be halted due to the partition running out
of space. Identifiers:
CCE-85618-7 References:
1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 8, APO11.04, APO13.01, BAI03.05, BAI04.04, DSS05.02, DSS05.04, DSS05.07, MEA02.01, 164.312(a)(2)(ii), 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.2, SR 7.6, A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.17.2.1, CIP-007-3 R6.5, CM-6(a), AU-4, SC-5(2), PR.DS-4, PR.PT-1, PR.PT-4, FMT_SMF_EXT.1, SRG-OS-000341-GPOS-00132, SRG-OS-000480-GPOS-00227, SRG-APP-000357-CTR-000800, SLES-15-030810, 1.1.16, R71, SLES-15-150150480, SV-234980r991589_rule |
Ensure /var/tmp Located On Separate Partition
[ref]ruleThe /var/tmp directory is a world-writable directory used
for temporary file storage. Ensure it has its own partition or
logical volume at installation time, or migrate it using LVM. Rationale:The /var/tmp partition is used as temporary storage by many programs.
Placing /var/tmp in its own partition enables the setting of more
restrictive mount options, which can help protect programs which use it. |
GNOME Desktop Environment
[ref]groupGNOME is a graphical desktop environment bundled with many Linux distributions that
allow users to easily interact with the operating system graphically rather than
textually. The GNOME Graphical Display Manager (GDM) provides login, logout, and user
switching contexts as well as display server management.
GNOME is developed by the GNOME Project and is considered the default
Red Hat Graphical environment.
For more information on GNOME and the GNOME Project, see https://www.gnome.org. |
| contains 10 rules |
Configure GNOME Login Screen
[ref]groupIn the default GNOME desktop, the login is displayed after system boot
and can display user accounts, allow users to reboot the system, and allow users to
login automatically and/or with a guest account. The login screen should be configured
to prevent such behavior.
For more information about enforcing preferences in the GNOME3 environment using the DConf
configuration system, see https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/desktop_migration_and_administration_guide/> and the man page dconf(1). |
| contains 2 rules |
Disable the GNOME3 Login User List
[ref]ruleIn the default graphical environment, users logging directly into the
system are greeted with a login screen that displays all known users.
This functionality should be disabled by setting disable-user-list
to true.
To disable, add or edit disable-user-list to
/etc/dconf/db/gdm.d/00-security-settings. For example:
[org/gnome/login-screen]
disable-user-list=true
Once the setting has been added, add a lock to
/etc/dconf/db/gdm.d/locks/00-security-settings-lock to prevent
user modification. For example:
/org/gnome/login-screen/disable-user-list
After the settings have been set, run dconf update.Rationale:Leaving the user list enabled is a security risk since it allows anyone
with physical access to the system to quickly enumerate known user accounts
without logging in. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm; then
# Check for setting in any of the DConf db directories
# If files contain ibus or distro, ignore them.
# The assignment assumes that individual filenames don't contain :
readarray -t SETTINGSFILES < <(grep -r "\\[org/gnome/login-screen\\]" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|gdm.d' | cut -d":" -f1)
DCONFFILE="/etc/dconf/db/gdm.d/00-security-settings"
DBDIR="/etc/dconf/db/gdm.d"
mkdir -p "${DBDIR}"
# Comment out the configurations in databases different from the target one
if [ "${#SETTINGSFILES[@]}" -ne 0 ]
then
if grep -q "^\\s*disable-user-list\\s*=" "${SETTINGSFILES[@]}"
then
sed -Ei "s/(^\s*)disable-user-list(\s*=)/#\1disable-user-list\2/g" "${SETTINGSFILES[@]}"
fi
fi
[ ! -z "${DCONFFILE}" ] && echo "" >> "${DCONFFILE}"
if ! grep -q "\\[org/gnome/login-screen\\]" "${DCONFFILE}"
then
printf '%s\n' "[org/gnome/login-screen]" >> ${DCONFFILE}
fi
escaped_value="$(sed -e 's/\\/\\\\/g' <<< "true")"
if grep -q "^\\s*disable-user-list\\s*=" "${DCONFFILE}"
then
sed -i "s/\\s*disable-user-list\\s*=\\s*.*/disable-user-list=${escaped_value}/g" "${DCONFFILE}"
else
sed -i "\\|\\[org/gnome/login-screen\\]|a\\disable-user-list=${escaped_value}" "${DCONFFILE}"
fi
dconf update
# Check for setting in any of the DConf db directories
LOCKFILES=$(grep -r "^/org/gnome/login-screen/disable-user-list$" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|gdm.d' | grep ":" | cut -d":" -f1)
LOCKSFOLDER="/etc/dconf/db/gdm.d/locks"
mkdir -p "${LOCKSFOLDER}"
# Comment out the configurations in databases different from the target one
if [[ ! -z "${LOCKFILES}" ]]
then
sed -i -E "s|^/org/gnome/login-screen/disable-user-list$|#&|" "${LOCKFILES[@]}"
fi
if ! grep -qr "^/org/gnome/login-screen/disable-user-list$" /etc/dconf/db/gdm.d/
then
echo "/org/gnome/login-screen/disable-user-list" >> "/etc/dconf/db/gdm.d/locks/00-security-settings-lock"
fi
dconf update
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | unknown |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92520-6
- NIST-800-53-AC-23
- NIST-800-53-CM-6(a)
- dconf_gnome_disable_user_list
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Disable the GNOME3 Login User List
community.general.ini_file:
dest: /etc/dconf/db/gdm.d/00-security-settings
section: org/gnome/login-screen
option: disable-user-list
value: 'true'
no_extra_spaces: true
create: true
register: result_ini
when: '"gdm" in ansible_facts.packages'
tags:
- CCE-92520-6
- NIST-800-53-AC-23
- NIST-800-53-CM-6(a)
- dconf_gnome_disable_user_list
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Prevent user modification of GNOME3 disablement of Login User List
ansible.builtin.lineinfile:
path: /etc/dconf/db/gdm.d/locks/00-security-settings-lock
regexp: ^/org/gnome/login-screen/disable-user-list$
line: /org/gnome/login-screen/disable-user-list
create: true
register: result_lineinfile
when: '"gdm" in ansible_facts.packages'
tags:
- CCE-92520-6
- NIST-800-53-AC-23
- NIST-800-53-CM-6(a)
- dconf_gnome_disable_user_list
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Dconf Update
ansible.builtin.command: dconf update
when:
- '"gdm" in ansible_facts.packages'
- result_ini is changed or result_lineinfile is changed
tags:
- CCE-92520-6
- NIST-800-53-AC-23
- NIST-800-53-CM-6(a)
- dconf_gnome_disable_user_list
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
|
Disable XDMCP in GDM
[ref]ruleXDMCP is an unencrypted protocol, and therefore, presents a security risk, see e.g.
XDMCP Gnome docs.
To disable XDMCP support in Gnome, set Enable to false under the [xdmcp] configuration section in /etc/gdm/custom.conf. For example:
[xdmcp]
Enable=false
Rationale:XDMCP provides unencrypted remote access through the Gnome Display Manager (GDM) which does
not provide for the confidentiality and integrity of user passwords or the
remote session. If a privileged user were to login using XDMCP, the
privileged user password could be compromised due to typed XEvents
and keystrokes will traversing over the network in clear text. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm; then
# Try find '[xdmcp]' and 'Enable' in '/etc/gdm/custom.conf', if it exists, set
# to 'false', if it isn't here, add it, if '[xdmcp]' doesn't exist, add it there
if grep -qzosP '[[:space:]]*\[xdmcp]([^\n\[]*\n+)+?[[:space:]]*Enable' '/etc/gdm/custom.conf'; then
sed -i "s/Enable[^(\n)]*/Enable=false/" '/etc/gdm/custom.conf'
elif grep -qs '[[:space:]]*\[xdmcp]' '/etc/gdm/custom.conf'; then
sed -i "/[[:space:]]*\[xdmcp]/a Enable=false" '/etc/gdm/custom.conf'
else
if test -d "/etc/gdm"; then
printf '%s\n' '[xdmcp]' "Enable=false" >> '/etc/gdm/custom.conf'
else
echo "Config file directory '/etc/gdm' doesnt exist, not remediating, assuming non-applicability." >&2
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
GNOME Media Settings
[ref]groupGNOME media settings that apply to the graphical interface. |
| contains 3 rules |
Disable GNOME3 Automounting
[ref]ruleThe system's default desktop environment, GNOME3, will mount
devices and removable media (such as DVDs, CDs and USB flash drives) whenever
they are inserted into the system. To disable automount within GNOME3, add or set
automount to false in /etc/dconf/db/local.d/00-security-settings.
For example:
[org/gnome/desktop/media-handling]
automount=false
Once the settings have been added, add a lock to
/etc/dconf/db/local.d/locks/00-security-settings-lock to prevent user modification.
For example:
/org/gnome/desktop/media-handling/automount
After the settings have been set, run dconf update.Rationale:Disabling automatic mounting in GNOME3 can prevent
the introduction of malware via removable media.
It will, however, also prevent desktop users from legitimate use
of removable media. Identifiers:
CCE-92491-0 References:
12, 16, APO13.01, DSS01.04, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, 3.1.7, 4.3.3.2.2, 4.3.3.5.2, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.13, SR 1.2, SR 1.4, SR 1.5, SR 1.9, SR 2.1, SR 2.6, A.11.2.6, A.13.1.1, A.13.2.1, A.6.2.1, A.6.2.2, A.7.1.1, A.9.2.1, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.AC-6, SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227, SLES-15-151200180, 3.4.2, 3.4 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm; then
# Check for setting in any of the DConf db directories
# If files contain ibus or distro, ignore them.
# The assignment assumes that individual filenames don't contain :
readarray -t SETTINGSFILES < <(grep -r "\\[org/gnome/desktop/media-handling\\]" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|local.d' | cut -d":" -f1)
DCONFFILE="/etc/dconf/db/local.d/00-security-settings"
DBDIR="/etc/dconf/db/local.d"
mkdir -p "${DBDIR}"
# Comment out the configurations in databases different from the target one
if [ "${#SETTINGSFILES[@]}" -ne 0 ]
then
if grep -q "^\\s*automount\\s*=" "${SETTINGSFILES[@]}"
then
sed -Ei "s/(^\s*)automount(\s*=)/#\1automount\2/g" "${SETTINGSFILES[@]}"
fi
fi
[ ! -z "${DCONFFILE}" ] && echo "" >> "${DCONFFILE}"
if ! grep -q "\\[org/gnome/desktop/media-handling\\]" "${DCONFFILE}"
then
printf '%s\n' "[org/gnome/desktop/media-handling]" >> ${DCONFFILE}
fi
escaped_value="$(sed -e 's/\\/\\\\/g' <<< "false")"
if grep -q "^\\s*automount\\s*=" "${DCONFFILE}"
then
sed -i "s/\\s*automount\\s*=\\s*.*/automount=${escaped_value}/g" "${DCONFFILE}"
else
sed -i "\\|\\[org/gnome/desktop/media-handling\\]|a\\automount=${escaped_value}" "${DCONFFILE}"
fi
dconf update
# Check for setting in any of the DConf db directories
LOCKFILES=$(grep -r "^/org/gnome/desktop/media-handling/automount$" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|local.d' | grep ":" | cut -d":" -f1)
LOCKSFOLDER="/etc/dconf/db/local.d/locks"
mkdir -p "${LOCKSFOLDER}"
# Comment out the configurations in databases different from the target one
if [[ ! -z "${LOCKFILES}" ]]
then
sed -i -E "s|^/org/gnome/desktop/media-handling/automount$|#&|" "${LOCKFILES[@]}"
fi
if ! grep -qr "^/org/gnome/desktop/media-handling/automount$" /etc/dconf/db/local.d/
then
echo "/org/gnome/desktop/media-handling/automount" >> "/etc/dconf/db/local.d/locks/00-security-settings-lock"
fi
dconf update
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Disable GNOME3 Automount Opening
[ref]ruleThe system's default desktop environment, GNOME3, will mount
devices and removable media (such as DVDs, CDs and USB flash drives) whenever
they are inserted into the system. To disable automount-open within GNOME3, add or set
automount-open to false in /etc/dconf/db/local.d/00-security-settings.
For example:
[org/gnome/desktop/media-handling]
automount-open=false
Once the settings have been added, add a lock to
/etc/dconf/db/local.d/locks/00-security-settings-lock to prevent user modification.
For example:
/org/gnome/desktop/media-handling/automount-open
After the settings have been set, run dconf update.Rationale:Automatically mounting file systems permits easy introduction of unknown devices, thereby facilitating malicious activity.
Disabling automatic mounting in GNOME3 can prevent
the introduction of malware via removable media.
It will, however, also prevent desktop users from legitimate use
of removable media. Identifiers:
CCE-92492-8 References:
12, 16, APO13.01, DSS01.04, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, 3.1.7, 4.3.3.2.2, 4.3.3.5.2, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.13, SR 1.2, SR 1.4, SR 1.5, SR 1.9, SR 2.1, SR 2.6, A.11.2.6, A.13.1.1, A.13.2.1, A.6.2.1, A.6.2.2, A.7.1.1, A.9.2.1, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.AC-6, SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227, SLES-15-151200180, 3.4.2, 3.4 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm; then
# Check for setting in any of the DConf db directories
# If files contain ibus or distro, ignore them.
# The assignment assumes that individual filenames don't contain :
readarray -t SETTINGSFILES < <(grep -r "\\[org/gnome/desktop/media-handling\\]" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|local.d' | cut -d":" -f1)
DCONFFILE="/etc/dconf/db/local.d/00-security-settings"
DBDIR="/etc/dconf/db/local.d"
mkdir -p "${DBDIR}"
# Comment out the configurations in databases different from the target one
if [ "${#SETTINGSFILES[@]}" -ne 0 ]
then
if grep -q "^\\s*automount-open\\s*=" "${SETTINGSFILES[@]}"
then
sed -Ei "s/(^\s*)automount-open(\s*=)/#\1automount-open\2/g" "${SETTINGSFILES[@]}"
fi
fi
[ ! -z "${DCONFFILE}" ] && echo "" >> "${DCONFFILE}"
if ! grep -q "\\[org/gnome/desktop/media-handling\\]" "${DCONFFILE}"
then
printf '%s\n' "[org/gnome/desktop/media-handling]" >> ${DCONFFILE}
fi
escaped_value="$(sed -e 's/\\/\\\\/g' <<< "false")"
if grep -q "^\\s*automount-open\\s*=" "${DCONFFILE}"
then
sed -i "s/\\s*automount-open\\s*=\\s*.*/automount-open=${escaped_value}/g" "${DCONFFILE}"
else
sed -i "\\|\\[org/gnome/desktop/media-handling\\]|a\\automount-open=${escaped_value}" "${DCONFFILE}"
fi
dconf update
# Check for setting in any of the DConf db directories
LOCKFILES=$(grep -r "^/org/gnome/desktop/media-handling/automount-open$" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|local.d' | grep ":" | cut -d":" -f1)
LOCKSFOLDER="/etc/dconf/db/local.d/locks"
mkdir -p "${LOCKSFOLDER}"
# Comment out the configurations in databases different from the target one
if [[ ! -z "${LOCKFILES}" ]]
then
sed -i -E "s|^/org/gnome/desktop/media-handling/automount-open$|#&|" "${LOCKFILES[@]}"
fi
if ! grep -qr "^/org/gnome/desktop/media-handling/automount-open$" /etc/dconf/db/local.d/
then
echo "/org/gnome/desktop/media-handling/automount-open" >> "/etc/dconf/db/local.d/locks/00-security-settings-lock"
fi
dconf update
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Disable GNOME3 Automount running
[ref]ruleThe system's default desktop environment, GNOME3, will mount
devices and removable media (such as DVDs, CDs and USB flash drives) whenever
they are inserted into the system. To disable autorun-never within GNOME3, add or set
autorun-never to true in /etc/dconf/db/local.d/00-security-settings.
For example:
[org/gnome/desktop/media-handling]
autorun-never=true
Once the settings have been added, add a lock to
/etc/dconf/db/local.d/locks/00-security-settings-lock to prevent user modification.
For example:
/org/gnome/desktop/media-handling/autorun-never
After the settings have been set, run dconf update.Rationale:Automatically mounting file systems permits easy introduction of unknown devices, thereby facilitating malicious activity.
Disabling automatic mount running in GNOME3 can prevent
the introduction of malware via removable media.
It will, however, also prevent desktop users from legitimate use
of removable media. Identifiers:
CCE-92493-6 References:
12, 16, APO13.01, DSS01.04, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, 3.1.7, 4.3.3.2.2, 4.3.3.5.2, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.13, SR 1.2, SR 1.4, SR 1.5, SR 1.9, SR 2.1, SR 2.6, A.11.2.6, A.13.1.1, A.13.2.1, A.6.2.1, A.6.2.2, A.7.1.1, A.9.2.1, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.AC-6, SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227, SLES-15-151200210 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm; then
# Check for setting in any of the DConf db directories
# If files contain ibus or distro, ignore them.
# The assignment assumes that individual filenames don't contain :
readarray -t SETTINGSFILES < <(grep -r "\\[org/gnome/desktop/media-handling\\]" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|local.d' | cut -d":" -f1)
DCONFFILE="/etc/dconf/db/local.d/00-security-settings"
DBDIR="/etc/dconf/db/local.d"
mkdir -p "${DBDIR}"
# Comment out the configurations in databases different from the target one
if [ "${#SETTINGSFILES[@]}" -ne 0 ]
then
if grep -q "^\\s*autorun-never\\s*=" "${SETTINGSFILES[@]}"
then
sed -Ei "s/(^\s*)autorun-never(\s*=)/#\1autorun-never\2/g" "${SETTINGSFILES[@]}"
fi
fi
[ ! -z "${DCONFFILE}" ] && echo "" >> "${DCONFFILE}"
if ! grep -q "\\[org/gnome/desktop/media-handling\\]" "${DCONFFILE}"
then
printf '%s\n' "[org/gnome/desktop/media-handling]" >> ${DCONFFILE}
fi
escaped_value="$(sed -e 's/\\/\\\\/g' <<< "true")"
if grep -q "^\\s*autorun-never\\s*=" "${DCONFFILE}"
then
sed -i "s/\\s*autorun-never\\s*=\\s*.*/autorun-never=${escaped_value}/g" "${DCONFFILE}"
else
sed -i "\\|\\[org/gnome/desktop/media-handling\\]|a\\autorun-never=${escaped_value}" "${DCONFFILE}"
fi
dconf update
# Check for setting in any of the DConf db directories
LOCKFILES=$(grep -r "^/org/gnome/desktop/media-handling/autorun-never$" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|local.d' | grep ":" | cut -d":" -f1)
LOCKSFOLDER="/etc/dconf/db/local.d/locks"
mkdir -p "${LOCKSFOLDER}"
# Comment out the configurations in databases different from the target one
if [[ ! -z "${LOCKFILES}" ]]
then
sed -i -E "s|^/org/gnome/desktop/media-handling/autorun-never$|#&|" "${LOCKFILES[@]}"
fi
if ! grep -qr "^/org/gnome/desktop/media-handling/autorun-never$" /etc/dconf/db/local.d/
then
echo "/org/gnome/desktop/media-handling/autorun-never" >> "/etc/dconf/db/local.d/locks/00-security-settings-lock"
fi
dconf update
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Configure GNOME Screen Locking
[ref]groupIn the default GNOME3 desktop, the screen can be locked
by selecting the user name in the far right corner of the main panel and
selecting Lock.
The following sections detail commands to enforce idle activation of the screensaver,
screen locking, a blank-screen screensaver, and an idle activation time.
Because users should be trained to lock the screen when they
step away from the computer, the automatic locking feature is only
meant as a backup.
The root account can be screen-locked; however, the root account should
never be used to log into an X Windows environment and should only
be used to for direct login via console in emergency circumstances.
For more information about enforcing preferences in the GNOME3 environment using the DConf
configuration system, see http://wiki.gnome.org/dconf and
the man page dconf(1). |
| contains 4 rules |
Set GNOME3 Screensaver Inactivity Timeout
[ref]ruleThe idle time-out value for inactivity in the GNOME3 desktop is configured via the idle-delay
setting must be set under an appropriate configuration file(s) in the /etc/dconf/db/local.d directory
and locked in /etc/dconf/db/local.d/locks directory to prevent user modification.
For example, to configure the system for a 15 minute delay, add the following to
/etc/dconf/db/local.d/00-security-settings:
[org/gnome/desktop/session]
idle-delay=uint32 900 Rationale:A session time-out lock is a temporary action taken when a user stops work and moves away from
the immediate physical vicinity of the information system but does not logout because of the
temporary nature of the absence. Rather than relying on the user to manually lock their operating
system session prior to vacating the vicinity, GNOME3 can be configured to identify when
a user's session has idled and take action to initiate a session lock. Identifiers:
CCE-85669-0 References:
1, 12, 15, 16, 5.5.5, DSS05.04, DSS05.10, DSS06.10, 3.1.10, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, AC-11(a), AC-11.1 (ii), PR.AC-7, Req-8.1.8, SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012, SLES-15-010120, SLES-15-151200150, 8.2.8, 8.2, SV-234812r958402_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm; then
inactivity_timeout_value='900'
# Check for setting in any of the DConf db directories
# If files contain ibus or distro, ignore them.
# The assignment assumes that individual filenames don't contain :
readarray -t SETTINGSFILES < <(grep -r "\\[org/gnome/desktop/session\\]" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|local.d' | cut -d":" -f1)
DCONFFILE="/etc/dconf/db/local.d/00-security-settings"
DBDIR="/etc/dconf/db/local.d"
mkdir -p "${DBDIR}"
# Comment out the configurations in databases different from the target one
if [ "${#SETTINGSFILES[@]}" -ne 0 ]
then
if grep -q "^\\s*idle-delay\\s*=" "${SETTINGSFILES[@]}"
then
sed -Ei "s/(^\s*)idle-delay(\s*=)/#\1idle-delay\2/g" "${SETTINGSFILES[@]}"
fi
fi
[ ! -z "${DCONFFILE}" ] && echo "" >> "${DCONFFILE}"
if ! grep -q "\\[org/gnome/desktop/session\\]" "${DCONFFILE}"
then
printf '%s\n' "[org/gnome/desktop/session]" >> ${DCONFFILE}
fi
escaped_value="$(sed -e 's/\\/\\\\/g' <<< "uint32 ${inactivity_timeout_value}")"
if grep -q "^\\s*idle-delay\\s*=" "${DCONFFILE}"
then
sed -i "s/\\s*idle-delay\\s*=\\s*.*/idle-delay=${escaped_value}/g" "${DCONFFILE}"
else
sed -i "\\|\\[org/gnome/desktop/session\\]|a\\idle-delay=${escaped_value}" "${DCONFFILE}"
fi
dconf update
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | unknown |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85669-0
- CJIS-5.5.5
- DISA-STIG-SLES-15-010120
- NIST-800-171-3.1.10
- NIST-800-53-AC-11(a)
- NIST-800-53-AC-11.1 (ii)
- PCI-DSS-Req-8.1.8
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.8
- dconf_gnome_screensaver_idle_delay
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: XCCDF Value inactivity_timeout_value # promote to variable
set_fact:
inactivity_timeout_value: !!str 900
tags:
- always
- name: Set GNOME3 Screensaver Inactivity Timeout
community.general.ini_file:
dest: /etc/dconf/db/local.d/00-security-settings
section: org/gnome/desktop/session
option: idle-delay
value: uint32 {{ inactivity_timeout_value }}
create: true
no_extra_spaces: true
register: result_ini
when: '"gdm" in ansible_facts.packages'
tags:
- CCE-85669-0
- CJIS-5.5.5
- DISA-STIG-SLES-15-010120
- NIST-800-171-3.1.10
- NIST-800-53-AC-11(a)
- NIST-800-53-AC-11.1 (ii)
- PCI-DSS-Req-8.1.8
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.8
- dconf_gnome_screensaver_idle_delay
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Dconf Update
ansible.builtin.command: dconf update
when:
- '"gdm" in ansible_facts.packages'
- result_ini is changed
tags:
- CCE-85669-0
- CJIS-5.5.5
- DISA-STIG-SLES-15-010120
- NIST-800-171-3.1.10
- NIST-800-53-AC-11(a)
- NIST-800-53-AC-11.1 (ii)
- PCI-DSS-Req-8.1.8
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.8
- dconf_gnome_screensaver_idle_delay
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
|
Set GNOME3 Screensaver Lock Delay After Activation Period
[ref]ruleTo activate the locking delay of the screensaver in the GNOME3 desktop when
the screensaver is activated, add or set lock-delay to uint32 5 in
/etc/dconf/db/local.d/00-security-settings. For example:
[org/gnome/desktop/screensaver]
lock-delay=uint32 5
After the settings have been set, run dconf update.Rationale:A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity
of the information system but does not want to logout because of the temporary nature of the absence. Identifiers:
CCE-92495-1 References:
1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 3.1.10, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, AC-11(a), CM-6(a), PR.AC-7, Req-8.1.8, SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012, SLES-15-151200150, 8.2.8, 8.2 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm; then
var_screensaver_lock_delay='5'
# Check for setting in any of the DConf db directories
# If files contain ibus or distro, ignore them.
# The assignment assumes that individual filenames don't contain :
readarray -t SETTINGSFILES < <(grep -r "\\[org/gnome/desktop/screensaver\\]" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|local.d' | cut -d":" -f1)
DCONFFILE="/etc/dconf/db/local.d/00-security-settings"
DBDIR="/etc/dconf/db/local.d"
mkdir -p "${DBDIR}"
# Comment out the configurations in databases different from the target one
if [ "${#SETTINGSFILES[@]}" -ne 0 ]
then
if grep -q "^\\s*lock-delay\\s*=" "${SETTINGSFILES[@]}"
then
sed -Ei "s/(^\s*)lock-delay(\s*=)/#\1lock-delay\2/g" "${SETTINGSFILES[@]}"
fi
fi
[ ! -z "${DCONFFILE}" ] && echo "" >> "${DCONFFILE}"
if ! grep -q "\\[org/gnome/desktop/screensaver\\]" "${DCONFFILE}"
then
printf '%s\n' "[org/gnome/desktop/screensaver]" >> ${DCONFFILE}
fi
escaped_value="$(sed -e 's/\\/\\\\/g' <<< "uint32 ${var_screensaver_lock_delay}")"
if grep -q "^\\s*lock-delay\\s*=" "${DCONFFILE}"
then
sed -i "s/\\s*lock-delay\\s*=\\s*.*/lock-delay=${escaped_value}/g" "${DCONFFILE}"
else
sed -i "\\|\\[org/gnome/desktop/screensaver\\]|a\\lock-delay=${escaped_value}" "${DCONFFILE}"
fi
dconf update
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Ensure Users Cannot Change GNOME3 Screensaver Settings
[ref]ruleIf not already configured, ensure that users cannot change GNOME3 screensaver lock settings
by adding /org/gnome/desktop/screensaver/lock-delay
to /etc/dconf/db/local.d/locks/00-security-settings-lock to prevent user modification.
For example:
/org/gnome/desktop/screensaver/lock-delay
After the settings have been set, run dconf update.Rationale:A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate
physical vicinity of the information system but does not logout because of the temporary nature of the absence.
Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity,
GNOME desktops can be configured to identify when a user's session has idled and take action to initiate the
session lock. As such, users should not be allowed to change session settings. Identifiers:
CCE-92498-5 References:
1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 3.1.10, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), PR.AC-7, SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012, SLES-15-151200165 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm; then
# Check for setting in any of the DConf db directories
LOCKFILES=$(grep -r "^/org/gnome/desktop/screensaver/lock-delay$" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|local.d' | grep ":" | cut -d":" -f1)
LOCKSFOLDER="/etc/dconf/db/local.d/locks"
mkdir -p "${LOCKSFOLDER}"
# Comment out the configurations in databases different from the target one
if [[ ! -z "${LOCKFILES}" ]]
then
sed -i -E "s|^/org/gnome/desktop/screensaver/lock-delay$|#&|" "${LOCKFILES[@]}"
fi
if ! grep -qr "^/org/gnome/desktop/screensaver/lock-delay$" /etc/dconf/db/local.d/
then
echo "/org/gnome/desktop/screensaver/lock-delay" >> "/etc/dconf/db/local.d/locks/00-security-settings-lock"
fi
dconf update
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Ensure Users Cannot Change GNOME3 Session Idle Settings
[ref]ruleIf not already configured, ensure that users cannot change GNOME3 session idle settings
by adding /org/gnome/desktop/session/idle-delay
to /etc/dconf/db/local.d/locks/00-security-settings-lock to prevent user modification.
For example:
/org/gnome/desktop/session/idle-delay
After the settings have been set, run dconf update.Rationale:A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate
physical vicinity of the information system but does not logout because of the temporary nature of the absence.
Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity,
GNOME desktops can be configured to identify when a user's session has idled and take action to initiate the
session lock. As such, users should not be allowed to change session settings. Identifiers:
CCE-91245-1 References:
1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 3.1.10, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), PR.AC-7, Req-8.1.8, SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012, SLES-15-010120, SLES-15-151200165, 8.2.8, 8.2, SV-234812r958402_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm; then
# Check for setting in any of the DConf db directories
LOCKFILES=$(grep -r "^/org/gnome/desktop/session/idle-delay$" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|local.d' | grep ":" | cut -d":" -f1)
LOCKSFOLDER="/etc/dconf/db/local.d/locks"
mkdir -p "${LOCKSFOLDER}"
# Comment out the configurations in databases different from the target one
if [[ ! -z "${LOCKFILES}" ]]
then
sed -i -E "s|^/org/gnome/desktop/session/idle-delay$|#&|" "${LOCKFILES[@]}"
fi
if ! grep -qr "^/org/gnome/desktop/session/idle-delay$" /etc/dconf/db/local.d/
then
echo "/org/gnome/desktop/session/idle-delay" >> "/etc/dconf/db/local.d/locks/00-security-settings-lock"
fi
dconf update
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | unknown |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91245-1
- DISA-STIG-SLES-15-010120
- NIST-800-171-3.1.10
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.1.8
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.8
- dconf_gnome_session_idle_user_locks
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Prevent user modification of GNOME Session idle-delay
ansible.builtin.lineinfile:
path: /etc/dconf/db/local.d/locks/00-security-settings-lock
regexp: ^/org/gnome/desktop/session/idle-delay$
line: /org/gnome/desktop/session/idle-delay
create: true
register: result_lineinfile
when: '"gdm" in ansible_facts.packages'
tags:
- CCE-91245-1
- DISA-STIG-SLES-15-010120
- NIST-800-171-3.1.10
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.1.8
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.8
- dconf_gnome_session_idle_user_locks
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Dconf Update
ansible.builtin.command: dconf update
when:
- '"gdm" in ansible_facts.packages'
- result_lineinfile is changed
tags:
- CCE-91245-1
- DISA-STIG-SLES-15-010120
- NIST-800-171-3.1.10
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.1.8
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.8
- dconf_gnome_session_idle_user_locks
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
|
Remove the GDM Package Group
[ref]rule
By removing the gdm package, the system no longer has GNOME installed.
If X Windows is not installed then the system cannot boot into graphical user mode.
This prevents the system from being accidentally or maliciously booted into a graphical.target
mode. To do so, run the following command:
$ sudo yum remove gdm Rationale:Unnecessary service packages must not be installed to decrease the attack surface of the system.
A graphical environment is unnecessary for certain types of systems including a virtualization
hypervisor. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_gdm
class remove_gdm {
package { 'gdm':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm; then
# CAUTION: This remediation script will remove gdm
# from the system, and may remove any packages
# that depend on gdm. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "gdm"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92502-4
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_gdm_removed
- name: 'Remove the GDM Package Group: Ensure gdm is removed'
ansible.builtin.package:
name: gdm
state: absent
when: '"gdm" in ansible_facts.packages'
tags:
- CCE-92502-4
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_gdm_removed
|
Sudo, which stands for "su 'do'", provides the ability to delegate authority
to certain users, groups of users, or system administrators. When configured for system
users and/or groups, Sudo can allow a user or group to execute privileged commands
that normally only root is allowed to execute.
For more information on Sudo and addition Sudo configuration options, see
https://www.sudo.ws.
|
| contains 19 rules |
Install sudo Package
[ref]ruleThe sudo package can be installed with the following command:
$ sudo zypper install sudo Rationale:sudo is a program designed to allow a system administrator to give
limited root privileges to users and log root activity. The basic philosophy
is to give as few privileges as possible but still allow system users to
get their work done. Remediation script: (show)
[[packages]]
name = "sudo"
version = "*"
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_sudo
class install_sudo {
package { 'sudo':
ensure => 'installed',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
zypper install -y "sudo"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91183-4
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_sudo_installed
- name: Ensure sudo is installed
ansible.builtin.package:
name: sudo
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91183-4
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_sudo_installed
|
Verify Group Who Owns /etc/sudoers.d Directory
[ref]rule To properly set the group owner of /etc/sudoers.d, run the command:
$ sudo chgrp root /etc/sudoers.d
Rationale:The ownership of the /etc/sudoers.d directory by the root group is important
because this directory hosts sudo configuration. Protection of this
directory is critical for system security. Assigning the ownership to root
ensures exclusive control of the sudo configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newgroup=""
if getent group "root" >/dev/null 2>&1; then
newgroup="root"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "root is not a defined group on the system"
else
find -P /etc/sudoers.d/ -maxdepth 0 -type d ! -group root -exec chgrp --no-dereference "$newgroup" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92503-2
- configure_strategy
- directory_groupowner_etc_sudoersd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Check that the root group is defined
ansible.builtin.getent:
database: group
key: root
ignore_errors: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- directory_groupowner_etc_sudoersd_newgroup is undefined
tags:
- CCE-92503-2
- configure_strategy
- directory_groupowner_etc_sudoersd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the directory_groupowner_etc_sudoersd_newgroup variable if root found
ansible.builtin.set_fact:
directory_groupowner_etc_sudoersd_newgroup: root
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_facts.getent_group["root"] is defined
tags:
- CCE-92503-2
- configure_strategy
- directory_groupowner_etc_sudoersd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/sudoers.d/
ansible.builtin.file:
path: /etc/sudoers.d/
follow: false
state: directory
group: '{{ directory_groupowner_etc_sudoersd_newgroup }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92503-2
- configure_strategy
- directory_groupowner_etc_sudoersd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns /etc/sudoers.d Directory
[ref]rule To properly set the owner of /etc/sudoers.d, run the command:
$ sudo chown root /etc/sudoers.d
Rationale:The ownership of the /etc/sudoers.d directory by the root user is important
because this directory hosts sudo configuration. Protection of this
directory is critical for system security. Assigning the ownership to root
ensures exclusive control of the sudo configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
find -P /etc/sudoers.d/ -maxdepth 0 -type d ! -user 0 -exec chown --no-dereference "$newown" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92512-3
- configure_strategy
- directory_owner_etc_sudoersd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the directory_owner_etc_sudoersd_newown variable if represented by uid
ansible.builtin.set_fact:
directory_owner_etc_sudoersd_newown: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92512-3
- configure_strategy
- directory_owner_etc_sudoersd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on directory /etc/sudoers.d/
ansible.builtin.file:
path: /etc/sudoers.d/
follow: false
state: directory
owner: '{{ directory_owner_etc_sudoersd_newown }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92512-3
- configure_strategy
- directory_owner_etc_sudoersd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions On /etc/sudoers.d Directory
[ref]rule To properly set the permissions of /etc/sudoers.d, run the command: $ sudo chmod 0750 /etc/sudoers.d Rationale:Setting correct permissions on the /etc/sudoers.d directory is important
because this directory hosts sudo configuration. Protection of this
directory is critical for system security. Restricting the permissions
ensures exclusive control of the sudo configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
find -H /etc/sudoers.d/ -maxdepth 0 -perm /u+s,g+ws,o+xwrt -type d -exec chmod u-s,g-ws,o-xwrt {} \;
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92525-5
- configure_strategy
- directory_permissions_etc_sudoersd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/sudoers.d/ file(s)
ansible.builtin.command: 'find -P /etc/sudoers.d/ -maxdepth 0 -perm /u+s,g+ws,o+xwrt -type
d '
register: files_found
changed_when: false
failed_when: false
check_mode: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92525-5
- configure_strategy
- directory_permissions_etc_sudoersd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set permissions for /etc/sudoers.d/ file(s)
ansible.builtin.file:
path: '{{ item }}'
mode: u-s,g-ws,o-xwrt
state: directory
with_items:
- '{{ files_found.stdout_lines }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92525-5
- configure_strategy
- directory_permissions_etc_sudoersd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Ensure sudo Runs In A Minimal Environment - sudo env_reset
[ref]ruleThe sudo env_reset tag, when specified, will run the command in a minimal environment,
containing the TERM, PATH, HOME, MAIL, SHELL, LOGNAME, USER and SUDO_* variables.
This should be enabled by making sure that the env_reset tag exists in
/etc/sudoers configuration file or any sudo configuration snippets
in /etc/sudoers.d/. Rationale:Forcing sudo to reset the environment ensures that environment variables are not passed on to the
command accidentally, preventing leak of potentially sensitive information. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if /usr/sbin/visudo -qcf /etc/sudoers; then
cp /etc/sudoers /etc/sudoers.bak
if ! grep -P '^[\s]*Defaults\b[^!\n]*\benv_reset.*$' /etc/sudoers; then
# sudoers file doesn't define Option env_reset
echo "Defaults env_reset" >> /etc/sudoers
fi
# Check validity of sudoers and cleanup bak
if /usr/sbin/visudo -qcf /etc/sudoers; then
rm -f /etc/sudoers.bak
else
echo "Fail to validate remediated /etc/sudoers, reverting to original file."
mv /etc/sudoers.bak /etc/sudoers
false
fi
else
echo "Skipping remediation, /etc/sudoers failed to validate"
false
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91184-2
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_add_env_reset
- name: Ensure env_reset is enabled in /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
regexp: ^[\s]*Defaults.*\benv_reset\b.*$
line: Defaults env_reset
validate: /usr/sbin/visudo -cf %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91184-2
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_add_env_reset
|
Ensure sudo Ignores Commands In Current Dir - sudo ignore_dot
[ref]ruleThe sudo ignore_dot tag, when specified, will ignore the current directory
in the PATH environment variable.
This should be enabled by making sure that the ignore_dot tag exists in
/etc/sudoers configuration file or any sudo configuration snippets
in /etc/sudoers.d/. Rationale:Ignoring the commands in the user's current directory prevents an attacker from executing commands
downloaded locally. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if /usr/sbin/visudo -qcf /etc/sudoers; then
cp /etc/sudoers /etc/sudoers.bak
if ! grep -P '^[\s]*Defaults\b[^!\n]*\bignore_dot.*$' /etc/sudoers; then
# sudoers file doesn't define Option ignore_dot
echo "Defaults ignore_dot" >> /etc/sudoers
fi
# Check validity of sudoers and cleanup bak
if /usr/sbin/visudo -qcf /etc/sudoers; then
rm -f /etc/sudoers.bak
else
echo "Fail to validate remediated /etc/sudoers, reverting to original file."
mv /etc/sudoers.bak /etc/sudoers
false
fi
else
echo "Skipping remediation, /etc/sudoers failed to validate"
false
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91185-9
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_add_ignore_dot
- name: Ensure ignore_dot is enabled in /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
regexp: ^[\s]*Defaults.*\bignore_dot\b.*$
line: Defaults ignore_dot
validate: /usr/sbin/visudo -cf %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91185-9
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_add_ignore_dot
|
Ensure Privileged Escalated Commands Cannot Execute Other Commands - sudo NOEXEC
[ref]ruleThe sudo NOEXEC tag, when specified, prevents user executed
commands from executing other commands, like a shell for example.
This should be enabled by making sure that the NOEXEC tag exists in
/etc/sudoers configuration file or any sudo configuration snippets
in /etc/sudoers.d/. Rationale:Restricting the capability of sudo allowed commands to execute sub-commands
prevents users from running programs with privileges they wouldn't have otherwise. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if /usr/sbin/visudo -qcf /etc/sudoers; then
cp /etc/sudoers /etc/sudoers.bak
if ! grep -P '^[\s]*Defaults\b[^!\n]*\bnoexec.*$' /etc/sudoers; then
# sudoers file doesn't define Option noexec
echo "Defaults noexec" >> /etc/sudoers
fi
# Check validity of sudoers and cleanup bak
if /usr/sbin/visudo -qcf /etc/sudoers; then
rm -f /etc/sudoers.bak
else
echo "Fail to validate remediated /etc/sudoers, reverting to original file."
mv /etc/sudoers.bak /etc/sudoers
false
fi
else
echo "Skipping remediation, /etc/sudoers failed to validate"
false
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91186-7
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
- sudo_add_noexec
- name: Ensure noexec is enabled in /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
regexp: ^[\s]*Defaults.*\bnoexec\b.*$
line: Defaults noexec
validate: /usr/sbin/visudo -cf %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91186-7
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
- sudo_add_noexec
|
Ensure Only Users Logged In To Real tty Can Execute Sudo - sudo requiretty
[ref]ruleThe sudo requiretty tag, when specified, will only execute sudo
commands from users logged in to a real tty.
This should be enabled by making sure that the requiretty tag exists in
/etc/sudoers configuration file or any sudo configuration snippets
in /etc/sudoers.d/. Rationale:Restricting the use cases in which a user is allowed to execute sudo commands
reduces the attack surface. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if /usr/sbin/visudo -qcf /etc/sudoers; then
cp /etc/sudoers /etc/sudoers.bak
if ! grep -P '^[\s]*Defaults\b[^!\n]*\brequiretty.*$' /etc/sudoers; then
# sudoers file doesn't define Option requiretty
echo "Defaults requiretty" >> /etc/sudoers
fi
# Check validity of sudoers and cleanup bak
if /usr/sbin/visudo -qcf /etc/sudoers; then
rm -f /etc/sudoers.bak
else
echo "Fail to validate remediated /etc/sudoers, reverting to original file."
mv /etc/sudoers.bak /etc/sudoers
false
fi
else
echo "Skipping remediation, /etc/sudoers failed to validate"
false
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91188-3
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_add_requiretty
- name: Ensure requiretty is enabled in /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
regexp: ^[\s]*Defaults.*\brequiretty\b.*$
line: Defaults requiretty
validate: /usr/sbin/visudo -cf %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91188-3
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_add_requiretty
|
Ensure sudo umask is appropriate - sudo umask
[ref]ruleThe sudo umask tag, when specified, will be added the to the user's umask in the
command environment.
The umask should be configured by making sure that the umask=0022 tag exists in
/etc/sudoers configuration file or any sudo configuration snippets
in /etc/sudoers.d/. Rationale:The umask value influences the permissions assigned to files when they are created.
A misconfigured umask value could result in files with excessive permissions that can be read or
written to by unauthorized users. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_sudo_umask='0022'
if /usr/sbin/visudo -qcf /etc/sudoers; then
cp /etc/sudoers /etc/sudoers.bak
if ! grep -P '^[\s]*Defaults\b[^!\n]*\bumask=\w+\b.*$' /etc/sudoers; then
# sudoers file doesn't define Option umask
echo "Defaults umask=${var_sudo_umask}" >> /etc/sudoers
else
# sudoers file defines Option umask, remediate if appropriate value is not set
if ! grep -P "^[\s]*Defaults.*\bumask=${var_sudo_umask}\b.*$" /etc/sudoers; then
escaped_variable=${var_sudo_umask//$'/'/$'\/'}
sed -Ei "s/(^[\s]*Defaults.*\bumask=)[-]?.+(\b.*$)/\1$escaped_variable\2/" /etc/sudoers
fi
fi
# Check validity of sudoers and cleanup bak
if /usr/sbin/visudo -qcf /etc/sudoers; then
rm -f /etc/sudoers.bak
else
echo "Fail to validate remediated /etc/sudoers, reverting to original file."
mv /etc/sudoers.bak /etc/sudoers
false
fi
else
echo "Skipping remediation, /etc/sudoers failed to validate"
false
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91189-1
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_add_umask
- name: XCCDF Value var_sudo_umask # promote to variable
set_fact:
var_sudo_umask: !!str 0022
tags:
- always
- name: Ensure umask is enabled with the appropriate value in /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
regexp: ^[\s]*Defaults\s(.*)\bumask=[-]?.+\b(.*)$
line: Defaults \1umask={{ var_sudo_umask }}\2
validate: /usr/sbin/visudo -cf %s
backrefs: true
register: edit_sudoers_umask_option
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91189-1
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_add_umask
- name: Enable umask option with appropriate value in /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
line: Defaults umask={{ var_sudo_umask }}
validate: /usr/sbin/visudo -cf %s
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- edit_sudoers_umask_option is defined and not edit_sudoers_umask_option.changed
tags:
- CCE-91189-1
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_add_umask
|
Ensure Only Users Logged In To Real tty Can Execute Sudo - sudo use_pty
[ref]ruleThe sudo use_pty tag, when specified, will only execute sudo
commands from users logged in to a real tty.
This should be enabled by making sure that the use_pty tag exists in
/etc/sudoers configuration file or any sudo configuration snippets
in /etc/sudoers.d/. Rationale:Requiring that sudo commands be run in a pseudo-terminal can prevent an attacker from retaining
access to the user's terminal after the main program has finished executing. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q sudo; }; then
if /usr/sbin/visudo -qcf /etc/sudoers; then
cp /etc/sudoers /etc/sudoers.bak
if ! grep -P '^[\s]*Defaults\b[^!\n]*\buse_pty.*$' /etc/sudoers; then
# sudoers file doesn't define Option use_pty
echo "Defaults use_pty" >> /etc/sudoers
fi
# Check validity of sudoers and cleanup bak
if /usr/sbin/visudo -qcf /etc/sudoers; then
rm -f /etc/sudoers.bak
else
echo "Fail to validate remediated /etc/sudoers, reverting to original file."
mv /etc/sudoers.bak /etc/sudoers
false
fi
else
echo "Skipping remediation, /etc/sudoers failed to validate"
false
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91190-9
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_add_use_pty
- name: Ensure use_pty is enabled in /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
regexp: ^[\s]*Defaults.*\buse_pty\b.*$
line: Defaults use_pty
validate: /usr/sbin/visudo -cf %s
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"sudo" in ansible_facts.packages'
tags:
- CCE-91190-9
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_add_use_pty
|
Ensure Sudo Logfile Exists - sudo logfile
[ref]ruleA custom log sudo file can be configured with the 'logfile' tag. This rule configures
a sudo custom logfile at the default location suggested by CIS, which uses
/var/log/sudo.log. Rationale:A sudo log file simplifies auditing of sudo commands. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q sudo; }; then
var_sudo_logfile='/var/log/sudo.log'
if /usr/sbin/visudo -qcf /etc/sudoers; then
cp /etc/sudoers /etc/sudoers.bak
if ! grep -P '^[\s]*Defaults\b[^!\n]*\blogfile\s*=\s*(?:"?([^",\s]+)"?).*$' /etc/sudoers; then
# sudoers file doesn't define Option logfile
echo "Defaults logfile=${var_sudo_logfile}" >> /etc/sudoers
else
# sudoers file defines Option logfile, remediate if appropriate value is not set
if ! grep -P "^[\s]*Defaults.*\blogfile=${var_sudo_logfile}\b.*$" /etc/sudoers; then
escaped_variable=${var_sudo_logfile//$'/'/$'\/'}
sed -Ei "s/(^[\s]*Defaults.*\blogfile=)[-]?.+(\b.*$)/\1$escaped_variable\2/" /etc/sudoers
fi
fi
# Check validity of sudoers and cleanup bak
if /usr/sbin/visudo -qcf /etc/sudoers; then
rm -f /etc/sudoers.bak
else
echo "Fail to validate remediated /etc/sudoers, reverting to original file."
mv /etc/sudoers.bak /etc/sudoers
false
fi
else
echo "Skipping remediation, /etc/sudoers failed to validate"
false
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91311-1
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- restrict_strategy
- sudo_custom_logfile
- name: XCCDF Value var_sudo_logfile # promote to variable
set_fact:
var_sudo_logfile: !!str /var/log/sudo.log
tags:
- always
- name: Ensure logfile is enabled with the appropriate value in /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
regexp: ^[\s]*Defaults\s(.*)\blogfile=[-]?.+\b(.*)$
line: Defaults \1logfile={{ var_sudo_logfile }}\2
validate: /usr/sbin/visudo -cf %s
backrefs: true
register: edit_sudoers_logfile_option
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"sudo" in ansible_facts.packages'
tags:
- CCE-91311-1
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- restrict_strategy
- sudo_custom_logfile
- name: Enable logfile option with appropriate value in /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
line: Defaults logfile={{ var_sudo_logfile }}
validate: /usr/sbin/visudo -cf %s
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"sudo" in ansible_facts.packages'
- edit_sudoers_logfile_option is defined and not edit_sudoers_logfile_option.changed
tags:
- CCE-91311-1
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- restrict_strategy
- sudo_custom_logfile
|
Ensure a dedicated group owns sudo
[ref]ruleRestrict the execution of privilege escalated commands to a dedicated group of users.
Ensure the group owner of /usr/bin/sudo is root. Warning:
Changing group owner of /usr/bin/sudo to a group with no member users will prevent
any and all escalatation of privileges.
Additionally, the system may become unmanageable if root logins are not allowed. Warning:
This rule doesn't come with a remediation, before remediating the sysadmin needs to add users to the dedicated sudo group. Rationale:Restricting the set of users able to execute commands as privileged user reduces the attack surface. |
Ensure Users Re-Authenticate for Privilege Escalation - sudo
[ref]ruleThe sudo NOPASSWD and !authenticate option, when
specified, allows a user to execute commands using sudo without having to
authenticate. This should be disabled by making sure that
NOPASSWD and/or !authenticate do not exist in
/etc/sudoers configuration file or any sudo configuration snippets
in /etc/sudoers.d/." Rationale:Without re-authentication, users may access resources or perform tasks for which they
do not have authorization.
When operating systems provide the capability to escalate a functional capability, it
is critical that the user re-authenticate. Identifiers:
CCE-85673-2 References:
1, 12, 15, 16, 5, DSS05.04, DSS05.10, DSS06.03, DSS06.10, 4.3.3.5.1, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-11, CM-6(a), PR.AC-1, PR.AC-7, SRG-OS-000373-GPOS-00156, SLES-15-010450, SLES-15-600300060, 1546, 2.2.6, 2.2, SV-234853r1050789_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
for f in /etc/sudoers /etc/sudoers.d/* ; do
if [ ! -e "$f" ] ; then
continue
fi
matching_list=$(grep -P '^(?!#).*[\s]+NOPASSWD[\s]*\:.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
# comment out "NOPASSWD" matches to preserve user data
sed -i "s|^${entry}$|# &|g" $f
done <<< "$matching_list"
/usr/sbin/visudo -cf $f &> /dev/null || echo "Fail to validate $f with visudo"
fi
done
for f in /etc/sudoers /etc/sudoers.d/* ; do
if [ ! -e "$f" ] ; then
continue
fi
matching_list=$(grep -P '^(?!#).*[\s]+\!authenticate.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
# comment out "!authenticate" matches to preserve user data
sed -i "s|^${entry}$|# &|g" $f
done <<< "$matching_list"
/usr/sbin/visudo -cf $f &> /dev/null || echo "Fail to validate $f with visudo"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85673-2
- DISA-STIG-SLES-15-010450
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-11
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_require_authentication
- name: Find /etc/sudoers.d/ files
ansible.builtin.find:
paths:
- /etc/sudoers.d/
register: sudoers
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85673-2
- DISA-STIG-SLES-15-010450
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-11
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_require_authentication
- name: Remove lines containing NOPASSWD from sudoers files
ansible.builtin.replace:
regexp: (^(?!#).*[\s]+NOPASSWD[\s]*\:.*$)
replace: '# \g<1>'
path: '{{ item.path }}'
validate: /usr/sbin/visudo -cf %s
with_items:
- path: /etc/sudoers
- '{{ sudoers.files }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85673-2
- DISA-STIG-SLES-15-010450
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-11
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_require_authentication
- name: Find /etc/sudoers.d/ files
ansible.builtin.find:
paths:
- /etc/sudoers.d/
register: sudoers
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85673-2
- DISA-STIG-SLES-15-010450
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-11
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_require_authentication
- name: Remove lines containing !authenticate from sudoers files
ansible.builtin.replace:
regexp: (^(?!#).*[\s]+\!authenticate.*$)
replace: '# \g<1>'
path: '{{ item.path }}'
validate: /usr/sbin/visudo -cf %s
with_items:
- path: /etc/sudoers
- '{{ sudoers.files }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85673-2
- DISA-STIG-SLES-15-010450
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-11
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_require_authentication
|
Require Re-Authentication When Using the sudo Command
[ref]ruleThe sudo timestamp_timeout tag sets the amount of time sudo password prompt waits.
The default timestamp_timeout value is 5 minutes.
The timestamp_timeout should be configured by making sure that the
timestamp_timeout tag exists in
/etc/sudoers configuration file or any sudo configuration snippets
in /etc/sudoers.d/.
If the value is set to an integer less than 0, the user's time stamp will not expire
and the user will not have to re-authenticate for privileged actions until the user's session is terminated. Rationale:Without re-authentication, users may access resources or perform tasks for which they
do not have authorization.
When operating systems provide the capability to escalate a functional capability, it
is critical that the user re-authenticate. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q sudo; }; then
var_sudo_timestamp_timeout='15'
if grep -Px '^[\s]*Defaults.*timestamp_timeout[\s]*=.*' /etc/sudoers.d/*; then
find /etc/sudoers.d/ -type f -exec sed -Ei "/^[[:blank:]]*Defaults.*timestamp_timeout[[:blank:]]*=.*/d" {} \;
fi
if /usr/sbin/visudo -qcf /etc/sudoers; then
cp /etc/sudoers /etc/sudoers.bak
if ! grep -P '^[\s]*Defaults.*timestamp_timeout[\s]*=[\s]*[-]?\w+.*$' /etc/sudoers; then
# sudoers file doesn't define Option timestamp_timeout
echo "Defaults timestamp_timeout=${var_sudo_timestamp_timeout}" >> /etc/sudoers
else
# sudoers file defines Option timestamp_timeout, remediate wrong values if present
if grep -qP "^[\s]*Defaults\s.*\btimestamp_timeout[\s]*=[\s]*(?!${var_sudo_timestamp_timeout}\b)[-]?\w+\b.*$" /etc/sudoers; then
sed -Ei "s/(^[[:blank:]]*Defaults.*timestamp_timeout[[:blank:]]*=)[[:blank:]]*[-]?\w+(.*$)/\1${var_sudo_timestamp_timeout}\2/" /etc/sudoers
fi
fi
# Check validity of sudoers and cleanup bak
if /usr/sbin/visudo -qcf /etc/sudoers; then
rm -f /etc/sudoers.bak
else
echo "Fail to validate remediated /etc/sudoers, reverting to original file."
mv /etc/sudoers.bak /etc/sudoers
false
fi
else
echo "Skipping remediation, /etc/sudoers failed to validate"
false
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85764-9
- DISA-STIG-SLES-15-020102
- NIST-800-53-IA-11
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_require_reauthentication
- name: XCCDF Value var_sudo_timestamp_timeout # promote to variable
set_fact:
var_sudo_timestamp_timeout: !!str 15
tags:
- always
- name: Require Re-Authentication When Using the sudo Command - Find /etc/sudoers.d/*
files containing 'Defaults timestamp_timeout'
ansible.builtin.find:
path: /etc/sudoers.d
patterns: '*'
contains: ^[\s]*Defaults\s.*\btimestamp_timeout[\s]*=.*
register: sudoers_d_defaults_timestamp_timeout
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"sudo" in ansible_facts.packages'
tags:
- CCE-85764-9
- DISA-STIG-SLES-15-020102
- NIST-800-53-IA-11
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_require_reauthentication
- name: Require Re-Authentication When Using the sudo Command - Remove 'Defaults timestamp_timeout'
from /etc/sudoers.d/* files
ansible.builtin.lineinfile:
path: '{{ item.path }}'
regexp: ^[\s]*Defaults\s.*\btimestamp_timeout[\s]*=.*
state: absent
with_items: '{{ sudoers_d_defaults_timestamp_timeout.files }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"sudo" in ansible_facts.packages'
tags:
- CCE-85764-9
- DISA-STIG-SLES-15-020102
- NIST-800-53-IA-11
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_require_reauthentication
- name: Require Re-Authentication When Using the sudo Command - Ensure timestamp_timeout
has the appropriate value in /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
regexp: ^[\s]*Defaults\s(.*)\btimestamp_timeout[\s]*=[\s]*[-]?\w+\b(.*)$
line: Defaults \1timestamp_timeout={{ var_sudo_timestamp_timeout }}\2
validate: /usr/sbin/visudo -cf %s
backrefs: true
register: edit_sudoers_timestamp_timeout_option
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"sudo" in ansible_facts.packages'
tags:
- CCE-85764-9
- DISA-STIG-SLES-15-020102
- NIST-800-53-IA-11
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_require_reauthentication
- name: Require Re-Authentication When Using the sudo Command - Enable timestamp_timeout
option with correct value in /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
line: Defaults timestamp_timeout={{ var_sudo_timestamp_timeout }}
validate: /usr/sbin/visudo -cf %s
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"sudo" in ansible_facts.packages'
- |
edit_sudoers_timestamp_timeout_option is defined and not edit_sudoers_timestamp_timeout_option.changed
tags:
- CCE-85764-9
- DISA-STIG-SLES-15-020102
- NIST-800-53-IA-11
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_require_reauthentication
- name: Require Re-Authentication When Using the sudo Command - Remove timestamp_timeout
wrong values in /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
regexp: ^[\s]*Defaults\s.*\btimestamp_timeout[\s]*=[\s]*(?!{{ var_sudo_timestamp_timeout
}}\b)[-]?\w+\b.*$
state: absent
validate: /usr/sbin/visudo -cf %s
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"sudo" in ansible_facts.packages'
tags:
- CCE-85764-9
- DISA-STIG-SLES-15-020102
- NIST-800-53-IA-11
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_require_reauthentication
|
The operating system must restrict privilege elevation to authorized personnel
[ref]ruleThe sudo command allows a user to execute programs with elevated
(administrator) privileges. It prompts the user for their password
and confirms your request to execute a command by checking a file,
called sudoers.
Restrict privileged actions by removing the following entries from the sudoers file:
ALL ALL=(ALL) ALL
ALL ALL=(ALL:ALL) ALL Warning:
This rule doesn't come with a remediation, as the exact requirement allows exceptions,
and removing lines from the sudoers file can make the system non-administrable. Rationale:If the "sudoers" file is not configured correctly, any user defined
on the system can initiate privileged actions on the target system. |
Ensure sudo only includes the default configuration directory
[ref]ruleAdministrators can configure authorized sudo users via drop-in files, and it is possible to include
other directories and configuration files from the file currently being parsed.
Make sure that /etc/sudoers only includes drop-in configuration files from /etc/sudoers.d,
or that no drop-in file is included.
Either the /etc/sudoers should contain only one #includedir directive pointing to
/etc/sudoers.d, and no file in /etc/sudoers.d/ should include other files or directories;
Or the /etc/sudoers should not contain any #include,
@include, #includedir or @includedir directives.
Note that the '#' character doesn't denote a comment in the configuration file. Rationale:Some sudo configuration options allow users to run programs without re-authenticating.
Use of these configuration options makes it easier for one compromised account to be used to
compromise other accounts. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
sudoers_config_file="/etc/sudoers"
sudoers_config_dir="/etc/sudoers.d"
sudoers_includedir_count=$(grep -c "#includedir" "$sudoers_config_file")
if [ "$sudoers_includedir_count" -gt 1 ]; then
sed -i "/#includedir/d" "$sudoers_config_file"
echo "#includedir /etc/sudoers.d" >> "$sudoers_config_file"
elif [ "$sudoers_includedir_count" -eq 0 ]; then
echo "#includedir /etc/sudoers.d" >> "$sudoers_config_file"
else
if ! grep -q "^#includedir /etc/sudoers.d" "$sudoers_config_file"; then
sed -i "s|^#includedir.*|#includedir /etc/sudoers.d|g" "$sudoers_config_file"
fi
fi
sed -Ei "/^#include\s/d; /^@includedir\s/d" "$sudoers_config_file"
if grep -Pr "^[#@]include(dir)?\s" "$sudoers_config_dir" ; then
sed -Ei "/^[#@]include(dir)?\s/d" "$sudoers_config_dir"/*
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91151-1
- DISA-STIG-SLES-15-020099
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- sudoers_default_includedir
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/sudoers
create: false
regexp: ^#includedir.*$
state: absent
check_mode: true
changed_when: false
register: dupes
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91151-1
- DISA-STIG-SLES-15-020099
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- sudoers_default_includedir
- name: Deduplicate values from /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
create: false
regexp: ^#includedir.*$
state: absent
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- dupes.found is defined and dupes.found > 1
tags:
- CCE-91151-1
- DISA-STIG-SLES-15-020099
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- sudoers_default_includedir
- name: Insert correct line into /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
create: false
regexp: ^#includedir.*$
line: '#includedir /etc/sudoers.d'
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91151-1
- DISA-STIG-SLES-15-020099
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- sudoers_default_includedir
- name: Ensure sudoers doesn't include other non-default file
ansible.builtin.lineinfile:
path: /etc/sudoers
create: false
regexp: ^[#@]include[\s]+.*$
state: absent
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91151-1
- DISA-STIG-SLES-15-020099
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- sudoers_default_includedir
- name: Ensure sudoers doesn't have non-default includedir
ansible.builtin.lineinfile:
path: /etc/sudoers
create: false
regexp: ^@includedir[\s]+.*$
state: absent
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91151-1
- DISA-STIG-SLES-15-020099
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- sudoers_default_includedir
- name: Find out if /etc/sudoers.d/* files contain file or directory includes
ansible.builtin.find:
path: /etc/sudoers.d
patterns: '*'
contains: ^[#@]include(dir)?\s.*$
register: sudoers_d_includes
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91151-1
- DISA-STIG-SLES-15-020099
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- sudoers_default_includedir
- name: Remove found occurrences of file and directory includes from /etc/sudoers.d/*
files
ansible.builtin.lineinfile:
path: '{{ item.path }}'
regexp: ^[#@]include(dir)?\s.*$
state: absent
with_items: '{{ sudoers_d_includes.files }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91151-1
- DISA-STIG-SLES-15-020099
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- sudoers_default_includedir
|
Explicit arguments in sudo specifications
[ref]ruleAll commands in the sudoers file must strictly specify the arguments allowed to be used for a given user.
If the command is supposed to be executed only without arguments, pass "" as an argument in the corresponding user specification. Warning:
This rule doesn't come with a remediation, as absence of arguments in the user spec doesn't mean that the command is intended to be executed with no arguments. Warning:
The rule can produce false findings when an argument contains a comma - sudoers syntax allows comma escaping using backslash, but the check doesn't support that. For example, root ALL=(ALL) echo 1\,2 allows root to execute echo 1,2, but the check would interpret it as two commands echo 1\ and 2. Rationale:Any argument can modify quite significantly the behavior of a program, whether regarding the
realized operation (read, write, delete, etc.) or accessed resources (path in a file system tree). To
avoid any possibility of misuse of a command by a user, the ambiguities must be removed at the
level of its specification.
For example, on some systems, the kernel messages are only accessible by root.
If a user nevertheless must have the privileges to read them, the argument of the dmesg command has to be restricted
in order to prevent the user from flushing the buffer through the -c option:
user ALL = dmesg ""
|
Don't define allowed commands in sudoers by means of exclusion
[ref]rulePolicies applied by sudo through the sudoers file should not involve negation.
Each user specification in the sudoers file contains a comma-delimited list of command specifications.
The definition can make use glob patterns, as well as of negations.
Indirect definition of those commands by means of exclusion of a set of commands is trivial to bypass, so it is not allowed to use such constructs. Warning:
This rule doesn't come with a remediation, as negations indicate design issues with the sudoers user specifications design. Just removing negations doesn't increase the security - you typically have to rethink the definition of allowed commands to fix the issue. Rationale:Specifying access right using negation is inefficient and can be easily circumvented.
For example, it is expected that a specification like
# To avoid absolutely , this rule can be easily circumvented!
user ALL = ALL ,!/ bin/sh
prevents the execution of the shell
but that’s not the case: just copy the binary /bin/sh to a different name to make it executable
again through the rule keyword ALL. |
Don't target root user in the sudoers file
[ref]ruleThe targeted users of a user specification should be, as much as possible, non privileged users (i.e.: non-root).
User specifications have to explicitly list the runas spec (i.e. the list of target users that can be impersonated), and ALL or root should not be used. Warning:
This rule doesn't come with a remediation, as the exact requirement allows exceptions, and removing lines from the sudoers file can make the system non-administrable. Rationale:It is common that the command to be executed does not require superuser rights (editing a file
whose the owner is not root, sending a signal to an unprivileged process,etc.). In order to limit
any attempt of privilege escalation through a command, it is better to apply normal user rights. |
Updating Software
[ref]groupThe zypper command line tool is used to install and
update software packages. The system also provides a graphical
software update tool in the System menu, in the Administration submenu,
called Software Update.
SUSE Linux Enterprise 15 systems contain an installed software catalog called
the RPM database, which records metadata of installed packages. Consistently using
zypper or the graphical Software Update for all software installation
allows for insight into the current inventory of installed software on the system.
|
| contains 4 rules |
Ensure GPG keys are configured
[ref]ruleThe operation system or installed application can be successfully bootstrapped
without the GPG key being trusted. However, you cannot install new packages or
update them until the keys are trusted.
Most packages managers implement GPG key signing to verify package integrity
during installation.
To verify GPG keys are configured correctly for your package manager,
one of the following command groups may provide the needed information
depending on the package manager in use.
In SUSE Linux distributions, the administrators have to follow the next steps:
1. Log on to the system as a user with administrator rights.
2. Locate and download package, for example zoom_x86_64.rpm
3. Locate and download the public key (GPG) from the software download site, for
example the key for zoom package is package-signing-key-5-12-6.pub
4. Import the key public key:
$ sudo rpm --import package-signing-key-5-12-6.pub
5. List the keys, for example the command:
$ sudo rpm -qa gpg-pubkey*
will provide:
gpg-pubkey-dd79b481-62fe7502
6. Get more details about the key, via the command:
$ sudo rpm -qa gpg-pubkey-dd79b481-62fe7502
7. Check the GPG key, for example the command:
$ sudo rpm -q gpg-pubkey --qf '%{name}-%{version}-%{release} --> %{summary}\n'
will provide:
gpg-pubkey-dd79b481-62fe7502 --> gpg(Zoom Video Communications, Inc. <CryptoOpsCodeSignProd@zoom.us>)
Rationale:It is important to ensure that updates are obtained from a valid source to protect
against spoofing that could lead to the inadvertent installation of malware on the
system. |
Ensure gpgcheck Enabled In Main zypper Configuration
[ref]ruleThe gpgcheck option controls whether
RPM packages' signatures are always checked prior to installation.
To configure zypper to check package signatures before installing
them, ensure the following line appears in /etc/zypp/zypp.conf in
the [main] section:
gpgcheck=1 Rationale:Changes to any software components can have significant effects on the
overall security of the operating system. This requirement ensures the
software has not been tampered with and that it has been provided by a
trusted vendor.
Accordingly, patches, service packs, device drivers, or operating system
components must be signed with a certificate recognized and approved by the
organization.
Verifying the authenticity of the software prior to installation
validates the integrity of the patch or upgrade received from a vendor.
This ensures the software has not been tampered with and that it has been
provided by a trusted vendor. Self-signed certificates are disallowed by
this requirement. Certificates used to verify the software must be from an
approved Certificate Authority (CA). Identifiers:
CCE-83290-7 References:
11, 2, 3, 9, 5.10.4.1, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, 3.4.8, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), SA-12, SA-12(10), CM-11(a), CM-11(b), PR.DS-6, PR.DS-8, PR.IP-1, FPT_TUD_EXT.1, FPT_TUD_EXT.2, Req-6.2, SRG-OS-000366-GPOS-00153, SLES-15-010430, 1.2.3, R59, SLES-15-150300030, 1493, 6.3.3, 6.3, SV-234852r1009613_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q zypper; then
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^gpgcheck")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "1"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^gpgcheck\\>" "/etc/zypp/zypp.conf"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^gpgcheck\\>.*/$escaped_formatted_output/gi" "/etc/zypp/zypp.conf"
else
if [[ -s "/etc/zypp/zypp.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/zypp/zypp.conf" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/zypp/zypp.conf"
fi
cce="CCE-83290-7"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/zypp/zypp.conf" >> "/etc/zypp/zypp.conf"
printf '%s\n' "$formatted_output" >> "/etc/zypp/zypp.conf"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83290-7
- CJIS-5.10.4.1
- DISA-STIG-SLES-15-010430
- NIST-800-171-3.4.8
- NIST-800-53-CM-11(a)
- NIST-800-53-CM-11(b)
- NIST-800-53-CM-5(3)
- NIST-800-53-CM-6(a)
- NIST-800-53-SA-12
- NIST-800-53-SA-12(10)
- NIST-800-53-SC-12
- NIST-800-53-SC-12(3)
- NIST-800-53-SI-7
- PCI-DSS-Req-6.2
- PCI-DSSv4-6.3
- PCI-DSSv4-6.3.3
- configure_strategy
- ensure_gpgcheck_globally_activated
- high_severity
- low_complexity
- medium_disruption
- no_reboot_needed
- name: Ensure GPG check is globally activated
community.general.ini_file:
dest: /etc/zypp/zypp.conf
section: main
option: gpgcheck
value: 1
no_extra_spaces: true
create: false
when: '"zypper" in ansible_facts.packages'
tags:
- CCE-83290-7
- CJIS-5.10.4.1
- DISA-STIG-SLES-15-010430
- NIST-800-171-3.4.8
- NIST-800-53-CM-11(a)
- NIST-800-53-CM-11(b)
- NIST-800-53-CM-5(3)
- NIST-800-53-CM-6(a)
- NIST-800-53-SA-12
- NIST-800-53-SA-12(10)
- NIST-800-53-SC-12
- NIST-800-53-SC-12(3)
- NIST-800-53-SI-7
- PCI-DSS-Req-6.2
- PCI-DSSv4-6.3
- PCI-DSSv4-6.3.3
- configure_strategy
- ensure_gpgcheck_globally_activated
- high_severity
- low_complexity
- medium_disruption
- no_reboot_needed
|
Ensure gpgcheck Enabled for All zypper Package Repositories
[ref]ruleTo ensure signature checking is not disabled for
any repos, remove any lines from files in /etc/zypp/repos.d of the form:
gpgcheck=0 Rationale:Verifying the authenticity of the software prior to installation validates
the integrity of the patch or upgrade received from a vendor. This ensures
the software has not been tampered with and that it has been provided by a
trusted vendor. Self-signed certificates are disallowed by this
requirement. Certificates used to verify the software must be from an
approved Certificate Authority (CA)." Identifiers:
CCE-85797-9 References:
11, 2, 3, 9, 5.10.4.1, APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02, 3.4.8, 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i), 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), SA-12, SA-12(10), CM-11(a), CM-11(b), PR.DS-6, PR.DS-8, PR.IP-1, FPT_TUD_EXT.1, FPT_TUD_EXT.2, Req-6.2, SRG-OS-000366-GPOS-00153, 1.2.3, R59, SLES-15-150300030, 1493, 6.3.3, 6.3 Remediation Shell script: (show)
sed -i 's/gpgcheck\s*=.*/gpgcheck=1/g' /etc/zypp/repos.d/*
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Grep for zypper repo section names
ansible.builtin.shell: |
set -o pipefail
grep -HEr '^\[.+\]' -r /etc/zypp/repos.d/
register: repo_grep_results
failed_when: repo_grep_results.rc not in [0, 1]
changed_when: false
tags:
- CCE-85797-9
- CJIS-5.10.4.1
- NIST-800-171-3.4.8
- NIST-800-53-CM-11(a)
- NIST-800-53-CM-11(b)
- NIST-800-53-CM-5(3)
- NIST-800-53-CM-6(a)
- NIST-800-53-SA-12
- NIST-800-53-SA-12(10)
- NIST-800-53-SC-12
- NIST-800-53-SC-12(3)
- NIST-800-53-SI-7
- PCI-DSS-Req-6.2
- PCI-DSSv4-6.3
- PCI-DSSv4-6.3.3
- enable_strategy
- ensure_gpgcheck_never_disabled
- high_severity
- low_complexity
- medium_disruption
- no_reboot_needed
- name: Set gpgcheck=1 for each zypper repo
community.general.ini_file:
path: '{{ item[0] }}'
section: '{{ item[1] }}'
option: gpgcheck
value: '1'
no_extra_spaces: true
loop: '{{ repo_grep_results.stdout |regex_findall( ''(.+\.repo):\[(.+)\]\n?'' )
if repo_grep_results is not skipped else [] }}'
when: repo_grep_results is not skipped
tags:
- CCE-85797-9
- CJIS-5.10.4.1
- NIST-800-171-3.4.8
- NIST-800-53-CM-11(a)
- NIST-800-53-CM-11(b)
- NIST-800-53-CM-5(3)
- NIST-800-53-CM-6(a)
- NIST-800-53-SA-12
- NIST-800-53-SA-12(10)
- NIST-800-53-SC-12
- NIST-800-53-SC-12(3)
- NIST-800-53-SI-7
- PCI-DSS-Req-6.2
- PCI-DSSv4-6.3
- PCI-DSSv4-6.3.3
- enable_strategy
- ensure_gpgcheck_never_disabled
- high_severity
- low_complexity
- medium_disruption
- no_reboot_needed
|
Ensure Software Patches Installed
[ref]rule
If the system is configured for online updates, invoking the following command will list available
security updates:
$ sudo zypper refresh && sudo zypper list-patches -g security
NOTE: U.S. Defense systems are required to be patched within 30 days or sooner as local policy
dictates.Warning:
The OVAL feed of SUSE Linux Enterprise 15 is not a XML file, which may not be understood by all scanners. Rationale:Installing software updates is a fundamental mitigation against
the exploitation of publicly-known vulnerabilities. If the most
recent security patches and updates are not installed, unauthorized
users may take advantage of weaknesses in the unpatched software. The
lack of prompt attention to patching could result in a system compromise. Identifiers:
CCE-83261-8 References:
18, 20, 4, 5.10.4.1, APO12.01, APO12.02, APO12.03, APO12.04, BAI03.10, DSS05.01, DSS05.02, 4.2.3, 4.2.3.12, 4.2.3.7, 4.2.3.9, A.12.6.1, A.14.2.3, A.16.1.3, A.18.2.2, A.18.2.3, SI-2(5), SI-2(c), CM-6(a), ID.RA-1, PR.IP-12, FMT_MOF_EXT.1, Req-6.2, SRG-OS-000480-GPOS-00227, SLES-15-010010, 1.9, R61, SLES-15-150300075, 1409, 6.3.3, 6.3, SV-234802r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | true |
|---|
| Strategy: | patch |
|---|
zypper patch -g security -y
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | true |
|---|
| Strategy: | patch |
|---|
- name: Security patches are up to date
ansible.builtin.package:
name: '*'
state: latest
tags:
- CCE-83261-8
- CJIS-5.10.4.1
- DISA-STIG-SLES-15-010010
- NIST-800-53-CM-6(a)
- NIST-800-53-SI-2(5)
- NIST-800-53-SI-2(c)
- PCI-DSS-Req-6.2
- PCI-DSSv4-6.3
- PCI-DSSv4-6.3.3
- high_disruption
- low_complexity
- medium_severity
- patch_strategy
- reboot_required
- security_patches_up_to_date
- skip_ansible_lint
|
Account and Access Control
[ref]groupIn traditional Unix security, if an attacker gains
shell access to a certain login account, they can perform any action
or access any file to which that account has access. Therefore,
making it more difficult for unauthorized people to gain shell
access to accounts, particularly to privileged accounts, is a
necessary part of securing a system. This section introduces
mechanisms for restricting access to accounts under
SUSE Linux Enterprise 15. |
| contains 81 rules |
Warning Banners for System Accesses
[ref]groupEach system should expose as little information about
itself as possible.
System banners, which are typically displayed just before a
login prompt, give out information about the service or the host's
operating system. This might include the distribution name and the
system kernel version, and the particular version of a network
service. This information can assist intruders in gaining access to
the system as it can reveal whether the system is running
vulnerable software. Most network services can be configured to
limit what information is displayed.
Many organizations implement security policies that require a
system banner provide notice of the system's ownership, provide
warning to unauthorized users, and remind authorized users of their
consent to monitoring. |
| contains 14 rules |
Implement a GUI Warning Banner
[ref]groupIn the default graphical environment, users logging
directly into the system are greeted with a login screen provided
by the GNOME Display Manager (GDM). The warning banner should be
displayed in this graphical environment for these users.
The following sections describe how to configure the GDM login
banner. |
| contains 2 rules |
Enable GNOME3 Login Warning Banner
[ref]ruleIn the default graphical environment, displaying a login warning banner
in the GNOME Display Manager's login screen can be enabled on the login
screen by setting banner-message-enable to true.
To enable, add or edit banner-message-enable to
/etc/dconf/db/gdm.d/00-security-settings. For example:
[org/gnome/login-screen]
banner-message-enable=true
Once the setting has been added, add a lock to
/etc/dconf/db/gdm.d/locks/00-security-settings-lock to prevent user modification.
For example:
/org/gnome/login-screen/banner-message-enable
After the settings have been set, run dconf update.
The banner text must also be set.Rationale:Display of a standardized and approved use notification before granting access to the operating system
ensures privacy and security notification verbiage used is consistent with applicable federal laws,
Executive Orders, directives, policies, regulations, standards, and guidance.
For U.S. Government systems, system use notifications are required only for access via login interfaces
with human users and are not required when such human interfaces do not exist. Identifiers:
CCE-83265-9 References:
1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 3.1.9, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, AC-8(a), AC-8(b), AC-8(c), PR.AC-7, SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088, SLES-15-010080, 1.10, SLES-15-151200120, SV-234808r958586_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm; then
# Check for setting in any of the DConf db directories
# If files contain ibus or distro, ignore them.
# The assignment assumes that individual filenames don't contain :
readarray -t SETTINGSFILES < <(grep -r "\\[org/gnome/login-screen\\]" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|gdm.d' | cut -d":" -f1)
DCONFFILE="/etc/dconf/db/gdm.d/00-security-settings"
DBDIR="/etc/dconf/db/gdm.d"
mkdir -p "${DBDIR}"
# Comment out the configurations in databases different from the target one
if [ "${#SETTINGSFILES[@]}" -ne 0 ]
then
if grep -q "^\\s*banner-message-enable\\s*=" "${SETTINGSFILES[@]}"
then
sed -Ei "s/(^\s*)banner-message-enable(\s*=)/#\1banner-message-enable\2/g" "${SETTINGSFILES[@]}"
fi
fi
[ ! -z "${DCONFFILE}" ] && echo "" >> "${DCONFFILE}"
if ! grep -q "\\[org/gnome/login-screen\\]" "${DCONFFILE}"
then
printf '%s\n' "[org/gnome/login-screen]" >> ${DCONFFILE}
fi
escaped_value="$(sed -e 's/\\/\\\\/g' <<< "true")"
if grep -q "^\\s*banner-message-enable\\s*=" "${DCONFFILE}"
then
sed -i "s/\\s*banner-message-enable\\s*=\\s*.*/banner-message-enable=${escaped_value}/g" "${DCONFFILE}"
else
sed -i "\\|\\[org/gnome/login-screen\\]|a\\banner-message-enable=${escaped_value}" "${DCONFFILE}"
fi
dconf update
# Check for setting in any of the DConf db directories
LOCKFILES=$(grep -r "^/org/gnome/login-screen/banner-message-enable$" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|gdm.d' | grep ":" | cut -d":" -f1)
LOCKSFOLDER="/etc/dconf/db/gdm.d/locks"
mkdir -p "${LOCKSFOLDER}"
# Comment out the configurations in databases different from the target one
if [[ ! -z "${LOCKFILES}" ]]
then
sed -i -E "s|^/org/gnome/login-screen/banner-message-enable$|#&|" "${LOCKFILES[@]}"
fi
if ! grep -qr "^/org/gnome/login-screen/banner-message-enable$" /etc/dconf/db/gdm.d/
then
echo "/org/gnome/login-screen/banner-message-enable" >> "/etc/dconf/db/gdm.d/locks/00-security-settings-lock"
fi
dconf update
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | unknown |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83265-9
- DISA-STIG-SLES-15-010080
- NIST-800-171-3.1.9
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(b)
- NIST-800-53-AC-8(c)
- dconf_gnome_banner_enabled
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Enable GNOME3 Login Warning Banner
community.general.ini_file:
dest: /etc/dconf/db/gdm.d/00-security-settings
section: org/gnome/login-screen
option: banner-message-enable
value: 'true'
create: true
no_extra_spaces: true
register: result_ini
when: '"gdm" in ansible_facts.packages'
tags:
- CCE-83265-9
- DISA-STIG-SLES-15-010080
- NIST-800-171-3.1.9
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(b)
- NIST-800-53-AC-8(c)
- dconf_gnome_banner_enabled
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Prevent user modification of GNOME banner-message-enabled
ansible.builtin.lineinfile:
path: /etc/dconf/db/gdm.d/locks/00-security-settings-lock
regexp: ^/org/gnome/login-screen/banner-message-enable$
line: /org/gnome/login-screen/banner-message-enable
create: true
register: result_lineinfile
when: '"gdm" in ansible_facts.packages'
tags:
- CCE-83265-9
- DISA-STIG-SLES-15-010080
- NIST-800-171-3.1.9
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(b)
- NIST-800-53-AC-8(c)
- dconf_gnome_banner_enabled
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Dconf Update
ansible.builtin.command: dconf update
when:
- '"gdm" in ansible_facts.packages'
- result_ini is changed or result_lineinfile is changed
tags:
- CCE-83265-9
- DISA-STIG-SLES-15-010080
- NIST-800-171-3.1.9
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(b)
- NIST-800-53-AC-8(c)
- dconf_gnome_banner_enabled
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
|
Set the GNOME3 Login Warning Banner Text
[ref]ruleIn the default graphical environment, configuring the login warning banner text
in the GNOME Display Manager's login screen can be configured on the login
screen by setting banner-message-text to 'APPROVED_BANNER'
where APPROVED_BANNER is the approved banner for your environment.
To enable, add or edit banner-message-text to
/etc/dconf/db/gdm.d/00-security-settings. For example:
[org/gnome/login-screen]
banner-message-text='APPROVED_BANNER'
Once the setting has been added, add a lock to
/etc/dconf/db/gdm.d/locks/00-security-settings-lock to prevent user modification.
For example:
/org/gnome/login-screen/banner-message-text
After the settings have been set, run dconf update.
When entering a warning banner that spans several lines, remember
to begin and end the string with ' and use \n for new lines.Rationale:An appropriate warning message reinforces policy awareness during the logon
process and facilitates possible legal action against attackers. Identifiers:
CCE-83266-7 References:
1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 3.1.9, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, AC-8(a), AC-8(c), PR.AC-7, SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088, SLES-15-010090, 1.10, SLES-15-151200120, SV-234809r958586_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q gdm; then
login_banner_text='^(Authorized[\s\n]+users[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$'
# Multiple regexes transform the banner regex into a usable banner
# 0 - Remove anchors around the banner text
login_banner_text=$(echo "$login_banner_text" | sed 's/^\^\(.*\)\$$/\1/g')
# 1 - Keep only the first banners if there are multiple
# (dod_banners contains the long and short banner)
login_banner_text=$(echo "$login_banner_text" | sed 's/^(\(.*\.\)|.*)$/\1/g')
# 2 - Add spaces ' '. (Transforms regex for "space or newline" into a " ")
login_banner_text=$(echo "$login_banner_text" | sed 's/\[\\s\\n\]+/ /g')
# 3 - Adds newline "tokens". (Transforms "(?:\[\\n\]+|(?:\\n)+)" into "(n)*")
login_banner_text=$(echo "$login_banner_text" | sed 's/(?:\[\\n\]+|(?:\\\\n)+)/(n)*/g')
# 4 - Remove any leftover backslash. (From any parenthesis in the banner, for example).
login_banner_text=$(echo "$login_banner_text" | sed 's/\\//g')
# 5 - Removes the newline "token." (Transforms them into newline escape sequences "\n").
# ( Needs to be done after 4, otherwise the escapce sequence will become just "n".
login_banner_text=$(echo "$login_banner_text" | sed 's/(n)\*/\\n/g')
# Check for setting in any of the DConf db directories
# If files contain ibus or distro, ignore them.
# The assignment assumes that individual filenames don't contain :
readarray -t SETTINGSFILES < <(grep -r "\\[org/gnome/login-screen\\]" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|gdm.d' | cut -d":" -f1)
DCONFFILE="/etc/dconf/db/gdm.d/00-security-settings"
DBDIR="/etc/dconf/db/gdm.d"
mkdir -p "${DBDIR}"
# Comment out the configurations in databases different from the target one
if [ "${#SETTINGSFILES[@]}" -ne 0 ]
then
if grep -q "^\\s*banner-message-text\\s*=" "${SETTINGSFILES[@]}"
then
sed -Ei "s/(^\s*)banner-message-text(\s*=)/#\1banner-message-text\2/g" "${SETTINGSFILES[@]}"
fi
fi
[ ! -z "${DCONFFILE}" ] && echo "" >> "${DCONFFILE}"
if ! grep -q "\\[org/gnome/login-screen\\]" "${DCONFFILE}"
then
printf '%s\n' "[org/gnome/login-screen]" >> ${DCONFFILE}
fi
escaped_value="$(sed -e 's/\\/\\\\/g' <<< "'${login_banner_text}'")"
if grep -q "^\\s*banner-message-text\\s*=" "${DCONFFILE}"
then
sed -i "s/\\s*banner-message-text\\s*=\\s*.*/banner-message-text=${escaped_value}/g" "${DCONFFILE}"
else
sed -i "\\|\\[org/gnome/login-screen\\]|a\\banner-message-text=${escaped_value}" "${DCONFFILE}"
fi
dconf update
# Check for setting in any of the DConf db directories
LOCKFILES=$(grep -r "^/org/gnome/login-screen/banner-message-text$" "/etc/dconf/db/" \
| grep -v 'distro\|ibus\|gdm.d' | grep ":" | cut -d":" -f1)
LOCKSFOLDER="/etc/dconf/db/gdm.d/locks"
mkdir -p "${LOCKSFOLDER}"
# Comment out the configurations in databases different from the target one
if [[ ! -z "${LOCKFILES}" ]]
then
sed -i -E "s|^/org/gnome/login-screen/banner-message-text$|#&|" "${LOCKFILES[@]}"
fi
if ! grep -qr "^/org/gnome/login-screen/banner-message-text$" /etc/dconf/db/gdm.d/
then
echo "/org/gnome/login-screen/banner-message-text" >> "/etc/dconf/db/gdm.d/locks/00-security-settings-lock"
fi
dconf update
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | unknown |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83266-7
- DISA-STIG-SLES-15-010090
- NIST-800-171-3.1.9
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(c)
- dconf_gnome_login_banner_text
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: XCCDF Value login_banner_text # promote to variable
set_fact:
login_banner_text: !!str ^(Authorized[\s\n]+users[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$
tags:
- always
- name: Set the GNOME3 Login Warning Banner Text
ansible.builtin.file:
path: /etc/dconf/db/{{ item }}
owner: root
group: root
mode: 493
state: directory
with_items:
- gdm.d
- gdm.d/locks
when: '"gdm" in ansible_facts.packages'
tags:
- CCE-83266-7
- DISA-STIG-SLES-15-010090
- NIST-800-171-3.1.9
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(c)
- dconf_gnome_login_banner_text
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Set the GNOME3 Login Warning Banner Text
ansible.builtin.file:
path: /etc/dconf/db/gdm.d/{{ item }}
owner: root
group: root
mode: 420
state: touch
with_items:
- 00-security-settings
- locks/00-security-settings-lock
when: '"gdm" in ansible_facts.packages'
tags:
- CCE-83266-7
- DISA-STIG-SLES-15-010090
- NIST-800-171-3.1.9
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(c)
- dconf_gnome_login_banner_text
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Set the GNOME3 Login Warning Banner Text
community.general.ini_file:
dest: /etc/dconf/db/gdm.d/00-security-settings
section: org/gnome/login-screen
option: banner-message-text
value: '''{{ login_banner_text | regex_replace("^\^(.*)\$$", "\1") | regex_replace("^\((.*\.)\|.*\)$",
"\1") | regex_replace("\[\\s\\n\]\+"," ") | regex_replace("\(\?:\[\\n\]\+\|\(\?:\\\\n\)\+\)",
"(n)*") | regex_replace("\\", "") | regex_replace("\(n\)\*", "\\n") }}'''
create: true
no_extra_spaces: true
register: result_ini
when: '"gdm" in ansible_facts.packages'
tags:
- CCE-83266-7
- DISA-STIG-SLES-15-010090
- NIST-800-171-3.1.9
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(c)
- dconf_gnome_login_banner_text
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Prevent user modification of the GNOME3 Login Warning Banner Text
ansible.builtin.lineinfile:
path: /etc/dconf/db/gdm.d/locks/00-security-settings-lock
regexp: ^/org/gnome/login-screen/banner-message-text$
line: /org/gnome/login-screen/banner-message-text
create: true
state: present
register: result_lineinfile
when: '"gdm" in ansible_facts.packages'
tags:
- CCE-83266-7
- DISA-STIG-SLES-15-010090
- NIST-800-171-3.1.9
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(c)
- dconf_gnome_login_banner_text
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Dconf Update
ansible.builtin.command: dconf update
when:
- '"gdm" in ansible_facts.packages'
- result_ini is changed or result_lineinfile is changed
tags:
- CCE-83266-7
- DISA-STIG-SLES-15-010090
- NIST-800-171-3.1.9
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(c)
- dconf_gnome_login_banner_text
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
|
Modify the System Login Banner
[ref]rule
To configure the system login banner edit /etc/issue. Replace the
default text with a message compliant with the local site policy or a legal
disclaimer.
The DoD required text is either:
You are accessing a U.S. Government (USG) Information System (IS) that
is provided for USG-authorized use only. By using this IS (which includes
any device attached to this IS), you consent to the following conditions:
-The USG routinely intercepts and monitors communications on this IS
for purposes including, but not limited to, penetration testing, COMSEC
monitoring, network operations and defense, personnel misconduct (PM), law
enforcement (LE), and counterintelligence (CI) investigations.
-At any time, the USG may inspect and seize data stored on this IS.
-Communications using, or data stored on, this IS are not private,
are subject to routine monitoring, interception, and search, and may be
disclosed or used for any USG-authorized purpose.
-This IS includes security measures (e.g., authentication and access
controls) to protect USG interests -- not for your personal benefit or
privacy.
-Notwithstanding the above, using this IS does not constitute consent
to PM, LE or CI investigative searching or monitoring of the content of
privileged communications, or work product, related to personal
representation or services by attorneys, psychotherapists, or clergy, and
their assistants. Such communications and work product are private and
confidential. See User Agreement for details.
OR:
I've read & consent to terms in IS user agreem't. Rationale:Display of a standardized and approved use notification before granting
access to the operating system ensures privacy and security notification
verbiage used is consistent with applicable federal laws, Executive Orders,
directives, policies, regulations, standards, and guidance.
System use notifications are required only for access via login interfaces
with human users and are not required when such human interfaces do not
exist. Identifiers:
CCE-83262-6 References:
1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 3.1.9, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, AC-8(a), AC-8(c), PR.AC-7, SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088, SLES-15-010020, 1.8.1.2, SLES-15-151050030, SV-234803r958390_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
login_banner_text='^(Authorized[\s\n]+users[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$'
# Multiple regexes transform the banner regex into a usable banner
# 0 - Remove anchors around the banner text
login_banner_text=$(echo "$login_banner_text" | sed 's/^\^\(.*\)\$$/\1/g')
# 1 - Keep only the first banners if there are multiple
# (dod_banners contains the long and short banner)
login_banner_text=$(echo "$login_banner_text" | sed 's/^(\(.*\.\)|.*)$/\1/g')
# 2 - Add spaces ' '. (Transforms regex for "space or newline" into a " ")
login_banner_text=$(echo "$login_banner_text" | sed 's/\[\\s\\n\]+/ /g')
# 3 - Adds newlines. (Transforms "(?:\[\\n\]+|(?:\\n)+)" into "\n")
login_banner_text=$(echo "$login_banner_text" | sed 's/(?:\[\\n\]+|(?:\\\\n)+)/\n/g')
# 4 - Remove any leftover backslash. (From any parenthesis in the banner, for example).
login_banner_text=$(echo "$login_banner_text" | sed 's/\\//g')
formatted=$(echo "$login_banner_text" | fold -sw 80)
zypper install -y "issue-generator"
cat <<EOF >/etc/issue.d/99-oscap-setting
$formatted
EOF
/usr/bin/systemctl enable "issue-generator"
if [[ $(/usr/bin/systemctl is-system-running) != "offline" ]]; then
/usr/bin/systemctl start "issue-generator"
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
if /usr/bin/systemctl --failed | grep -q "issue-generator"; then
/usr/bin/systemctl reset-failed "issue-generator"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | unknown |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83262-6
- DISA-STIG-SLES-15-010020
- NIST-800-171-3.1.9
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(c)
- banner_etc_issue
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: XCCDF Value login_banner_text # promote to variable
set_fact:
login_banner_text: !!str ^(Authorized[\s\n]+users[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$
tags:
- always
- name: Modify the System Login Banner Ensure issue-generator is Installed
ansible.builtin.package:
name: issue-generator
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83262-6
- DISA-STIG-SLES-15-010020
- NIST-800-171-3.1.9
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(c)
- banner_etc_issue
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Modify the System Login Banner - Ensure Correct Banner
ansible.builtin.copy:
dest: /etc/issue.d/99-oscap-setting
content: '{{ login_banner_text | regex_replace("^\^(.*)\$$", "\1") | regex_replace("^\((.*\.)\|.*\)$",
"\1") | regex_replace("\[\\s\\n\]\+"," ") | regex_replace("\(\?:\[\\n\]\+\|\(\?:\\\\n\)\+\)",
"\n") | regex_replace("\\", "") | wordwrap() }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83262-6
- DISA-STIG-SLES-15-010020
- NIST-800-171-3.1.9
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(c)
- banner_etc_issue
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: Modify the System Login Banner - Restart issue-generator Service on Issue
Configuration Change
ansible.builtin.systemd:
name: issue-generator
enabled: 'yes'
state: restarted
masked: 'no'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83262-6
- DISA-STIG-SLES-15-010020
- NIST-800-171-3.1.9
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(c)
- banner_etc_issue
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
|
Modify the System Login Banner for Remote Connections
[ref]ruleTo configure the system login banner edit /etc/issue.net. Replace the
default text with a message compliant with the local site policy or a legal
disclaimer.
The DoD required text is either:
You are accessing a U.S. Government (USG) Information System (IS) that
is provided for USG-authorized use only. By using this IS (which includes
any device attached to this IS), you consent to the following conditions:
-The USG routinely intercepts and monitors communications on this IS
for purposes including, but not limited to, penetration testing, COMSEC
monitoring, network operations and defense, personnel misconduct (PM), law
enforcement (LE), and counterintelligence (CI) investigations.
-At any time, the USG may inspect and seize data stored on this IS.
-Communications using, or data stored on, this IS are not private,
are subject to routine monitoring, interception, and search, and may be
disclosed or used for any USG-authorized purpose.
-This IS includes security measures (e.g., authentication and access
controls) to protect USG interests -- not for your personal benefit or
privacy.
-Notwithstanding the above, using this IS does not constitute consent
to PM, LE or CI investigative searching or monitoring of the content of
privileged communications, or work product, related to personal
representation or services by attorneys, psychotherapists, or clergy, and
their assistants. Such communications and work product are private and
confidential. See User Agreement for details.
OR:
I've read & consent to terms in IS user agreem't. Rationale:Display of a standardized and approved use notification before granting
access to the operating system ensures privacy and security notification
verbiage used is consistent with applicable federal laws, Executive Orders,
directives, policies, regulations, standards, and guidance.
System use notifications are required only for access via login interfaces
with human users and are not required when such human interfaces do not
exist. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
remote_login_banner_text='^(Authorized[\s\n]+uses[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$'
# Multiple regexes transform the banner regex into a usable banner
# 0 - Remove anchors around the banner text
remote_login_banner_text=$(echo "$remote_login_banner_text" | sed 's/^\^\(.*\)\$$/\1/g')
# 1 - Keep only the first banners if there are multiple
# (dod_banners contains the long and short banner)
remote_login_banner_text=$(echo "$remote_login_banner_text" | sed 's/^(\(.*\.\)|.*)$/\1/g')
# 2 - Add spaces ' '. (Transforms regex for "space or newline" into a " ")
remote_login_banner_text=$(echo "$remote_login_banner_text" | sed 's/\[\\s\\n\]+/ /g')
# 3 - Adds newlines. (Transforms "(?:\[\\n\]+|(?:\\n)+)" into "\n")
remote_login_banner_text=$(echo "$remote_login_banner_text" | sed 's/(?:\[\\n\]+|(?:\\\\n)+)/\n/g')
# 4 - Remove any leftover backslash. (From any parenthesis in the banner, for example).
remote_login_banner_text=$(echo "$remote_login_banner_text" | sed 's/\\//g')
formatted=$(echo "$remote_login_banner_text" | fold -sw 80)
cat <<EOF >/etc/issue.net
$formatted
EOF
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | unknown |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91350-9
- banner_etc_issue_net
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: XCCDF Value remote_login_banner_text # promote to variable
set_fact:
remote_login_banner_text: !!str ^(Authorized[\s\n]+uses[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$
tags:
- always
- name: Modify the System Login Banner for Remote Connections - ensure correct banner
ansible.builtin.copy:
dest: /etc/issue.net
content: '{{ remote_login_banner_text | regex_replace("^\^(.*)\$$", "\1") | regex_replace("^\((.*\.)\|.*\)$",
"\1") | regex_replace("\[\\s\\n\]\+"," ") | regex_replace("\(\?:\[\\n\]\+\|\(\?:\\\\n\)\+\)",
"\n") | regex_replace("\\", "") | wordwrap() }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91350-9
- banner_etc_issue_net
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
|
Modify the System Message of the Day Banner
[ref]ruleTo configure the system message banner edit /etc/motd. Replace the
default text with a message compliant with the local site policy or a legal
disclaimer.
The DoD required text is either:
You are accessing a U.S. Government (USG) Information System (IS) that
is provided for USG-authorized use only. By using this IS (which includes
any device attached to this IS), you consent to the following conditions:
-The USG routinely intercepts and monitors communications on this IS
for purposes including, but not limited to, penetration testing, COMSEC
monitoring, network operations and defense, personnel misconduct (PM), law
enforcement (LE), and counterintelligence (CI) investigations.
-At any time, the USG may inspect and seize data stored on this IS.
-Communications using, or data stored on, this IS are not private,
are subject to routine monitoring, interception, and search, and may be
disclosed or used for any USG-authorized purpose.
-This IS includes security measures (e.g., authentication and access
controls) to protect USG interests -- not for your personal benefit or
privacy.
-Notwithstanding the above, using this IS does not constitute consent
to PM, LE or CI investigative searching or monitoring of the content of
privileged communications, or work product, related to personal
representation or services by attorneys, psychotherapists, or clergy, and
their assistants. Such communications and work product are private and
confidential. See User Agreement for details.
OR:
I've read & consent to terms in IS user agreem't. Rationale:Display of a standardized and approved use notification before granting
access to the operating system ensures privacy and security notification
verbiage used is consistent with applicable federal laws, Executive Orders,
directives, policies, regulations, standards, and guidance.
System use notifications are required only for access via login interfaces
with human users and are not required when such human interfaces do not
exist. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
motd_banner_text='^(Authorized[\s\n]+uses[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$'
# Multiple regexes transform the banner regex into a usable banner
# 0 - Remove anchors around the banner text
motd_banner_text=$(echo "$motd_banner_text" | sed 's/^\^\(.*\)\$$/\1/g')
# 1 - Keep only the first banners if there are multiple
# (dod_banners contains the long and short banner)
motd_banner_text=$(echo "$motd_banner_text" | sed 's/^(\(.*\.\)|.*)$/\1/g')
# 2 - Add spaces ' '. (Transforms regex for "space or newline" into a " ")
motd_banner_text=$(echo "$motd_banner_text" | sed 's/\[\\s\\n\]+/ /g')
# 3 - Adds newlines. (Transforms "(?:\[\\n\]+|(?:\\n)+)" into "\n")
motd_banner_text=$(echo "$motd_banner_text" | sed 's/(?:\[\\n\]+|(?:\\\\n)+)/\n/g')
# 4 - Remove any leftover backslash. (From any parenthesis in the banner, for example).
motd_banner_text=$(echo "$motd_banner_text" | sed 's/\\//g')
formatted=$(echo "$motd_banner_text" | fold -sw 80)
cat <<EOF >/etc/motd
$formatted
EOF
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | unknown |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91349-1
- banner_etc_motd
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- name: XCCDF Value motd_banner_text # promote to variable
set_fact:
motd_banner_text: !!str ^(Authorized[\s\n]+uses[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$
tags:
- always
- name: Modify the System Message of the Day Banner - ensure correct banner
ansible.builtin.copy:
dest: /etc/motd
content: '{{ motd_banner_text | regex_replace("^\^(.*)\$$", "\1") | regex_replace("^\((.*\.)\|.*\)$",
"\1") | regex_replace("\[\\s\\n\]\+"," ") | regex_replace("\(\?:\[\\n\]\+\|\(\?:\\\\n\)\+\)",
"\n") | regex_replace("\\", "") | wordwrap() }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91349-1
- banner_etc_motd
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
|
Verify Group Ownership of System Login Banner
[ref]rule
To properly set the group owner of /etc/issue, run the command:
$ sudo chgrp root /etc/issue
Rationale:Display of a standardized and approved use notification before granting
access to the operating system ensures privacy and security notification
verbiage used is consistent with applicable federal laws, Executive Orders,
directives, policies, regulations, standards, and guidance.
Proper group ownership will ensure that only root user can modify the banner. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
find -P /etc/issue.d/ -type f ! -group 0 -regextype posix-extended -regex '^.*$' -exec chgrp --no-dereference "$newgroup" {} \;
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_groupowner_etc_issue_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_etc_issue_newgroup: '0'
tags:
- CCE-91355-8
- configure_strategy
- file_groupowner_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/issue.d/ file(s) matching ^.*$ recursively
ansible.builtin.command: find -P /etc/issue.d/ -type f ! -group 0 -regextype posix-extended
-regex "^.*$"
register: files_found
changed_when: false
failed_when: false
check_mode: false
tags:
- CCE-91355-8
- configure_strategy
- file_groupowner_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/issue.d/ file(s) matching ^.*$
ansible.builtin.file:
path: '{{ item }}'
follow: false
group: '{{ file_groupowner_etc_issue_newgroup }}'
state: file
with_items:
- '{{ files_found.stdout_lines }}'
tags:
- CCE-91355-8
- configure_strategy
- file_groupowner_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Ownership of System Login Banner for Remote Connections
[ref]rule
To properly set the group owner of /etc/issue.net, run the command:
$ sudo chgrp root /etc/issue.net
Rationale:Display of a standardized and approved use notification before granting
access to the operating system ensures privacy and security notification
verbiage used is consistent with applicable federal laws, Executive Orders,
directives, policies, regulations, standards, and guidance.
Proper group ownership will ensure that only root user can modify the banner. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/issue.net" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/issue.net
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_groupowner_etc_issue_net_newgroup variable if represented by
gid
ansible.builtin.set_fact:
file_groupowner_etc_issue_net_newgroup: '0'
tags:
- CCE-91358-2
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.8
- configure_strategy
- file_groupowner_etc_issue_net
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/issue.net
ansible.builtin.stat:
path: /etc/issue.net
register: file_exists
tags:
- CCE-91358-2
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.8
- configure_strategy
- file_groupowner_etc_issue_net
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/issue.net
ansible.builtin.file:
path: /etc/issue.net
follow: false
group: '{{ file_groupowner_etc_issue_net_newgroup }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91358-2
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.8
- configure_strategy
- file_groupowner_etc_issue_net
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Ownership of Message of the Day Banner
[ref]rule
To properly set the group owner of /etc/motd, run the command:
$ sudo chgrp root /etc/motd
Rationale:Display of a standardized and approved use notification before granting
access to the operating system ensures privacy and security notification
verbiage used is consistent with applicable federal laws, Executive Orders,
directives, policies, regulations, standards, and guidance.
Proper group ownership will ensure that only root user can modify the banner. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/motd" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/motd
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_groupowner_etc_motd_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_etc_motd_newgroup: '0'
tags:
- CCE-91352-5
- configure_strategy
- file_groupowner_etc_motd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/motd
ansible.builtin.stat:
path: /etc/motd
register: file_exists
tags:
- CCE-91352-5
- configure_strategy
- file_groupowner_etc_motd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/motd
ansible.builtin.file:
path: /etc/motd
follow: false
group: '{{ file_groupowner_etc_motd_newgroup }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91352-5
- configure_strategy
- file_groupowner_etc_motd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify ownership of System Login Banner
[ref]rule
To properly set the owner of /etc/issue, run the command:
$ sudo chown root /etc/issue
Rationale:Display of a standardized and approved use notification before granting
access to the operating system ensures privacy and security notification
verbiage used is consistent with applicable federal laws, Executive Orders,
directives, policies, regulations, standards, and guidance.
Proper ownership will ensure that only root user can modify the banner. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
find -P /etc/issue.d/ -type f ! -user 0 -regextype posix-extended -regex '^.*$' -exec chown --no-dereference "$newown" {} \;
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_owner_etc_issue_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_etc_issue_newown: '0'
tags:
- CCE-91356-6
- configure_strategy
- file_owner_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/issue.d/ file(s) matching ^.*$ recursively
ansible.builtin.command: find -P /etc/issue.d/ -type f ! -user 0 -regextype posix-extended
-regex "^.*$"
register: files_found
changed_when: false
failed_when: false
check_mode: false
tags:
- CCE-91356-6
- configure_strategy
- file_owner_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/issue.d/ file(s) matching ^.*$
ansible.builtin.file:
path: '{{ item }}'
follow: false
owner: '{{ file_owner_etc_issue_newown }}'
state: file
with_items:
- '{{ files_found.stdout_lines }}'
tags:
- CCE-91356-6
- configure_strategy
- file_owner_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify ownership of System Login Banner for Remote Connections
[ref]rule
To properly set the owner of /etc/issue.net, run the command:
$ sudo chown root /etc/issue.net
Rationale:Display of a standardized and approved use notification before granting
access to the operating system ensures privacy and security notification
verbiage used is consistent with applicable federal laws, Executive Orders,
directives, policies, regulations, standards, and guidance.
Proper ownership will ensure that only root user can modify the banner. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/issue.net" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/issue.net
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_owner_etc_issue_net_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_etc_issue_net_newown: '0'
tags:
- CCE-91359-0
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.8
- configure_strategy
- file_owner_etc_issue_net
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/issue.net
ansible.builtin.stat:
path: /etc/issue.net
register: file_exists
tags:
- CCE-91359-0
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.8
- configure_strategy
- file_owner_etc_issue_net
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/issue.net
ansible.builtin.file:
path: /etc/issue.net
follow: false
owner: '{{ file_owner_etc_issue_net_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91359-0
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.8
- configure_strategy
- file_owner_etc_issue_net
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify ownership of Message of the Day Banner
[ref]rule
To properly set the owner of /etc/motd, run the command:
$ sudo chown root /etc/motd
Rationale:Display of a standardized and approved use notification before granting
access to the operating system ensures privacy and security notification
verbiage used is consistent with applicable federal laws, Executive Orders,
directives, policies, regulations, standards, and guidance.
Proper ownership will ensure that only root user can modify the banner. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/motd" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/motd
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_owner_etc_motd_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_etc_motd_newown: '0'
tags:
- CCE-91353-3
- configure_strategy
- file_owner_etc_motd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/motd
ansible.builtin.stat:
path: /etc/motd
register: file_exists
tags:
- CCE-91353-3
- configure_strategy
- file_owner_etc_motd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/motd
ansible.builtin.file:
path: /etc/motd
follow: false
owner: '{{ file_owner_etc_motd_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91353-3
- configure_strategy
- file_owner_etc_motd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify permissions on System Login Banner
[ref]rule
To properly set the permissions of /etc/issue, run the command:
$ sudo chmod 0644 /etc/issue Rationale:Display of a standardized and approved use notification before granting
access to the operating system ensures privacy and security notification
verbiage used is consistent with applicable federal laws, Executive Orders,
directives, policies, regulations, standards, and guidance.
Proper permissions will ensure that only root user can modify the banner. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/issue
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Test for existence /etc/issue
ansible.builtin.stat:
path: /etc/issue
register: file_exists
tags:
- CCE-91354-1
- configure_strategy
- file_permissions_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xws,o-xwt on /etc/issue
ansible.builtin.file:
path: /etc/issue
mode: u-xs,g-xws,o-xwt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91354-1
- configure_strategy
- file_permissions_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify permissions on System Login Banner for Remote Connections
[ref]rule
To properly set the permissions of /etc/issue.net, run the command:
$ sudo chmod 0644 /etc/issue.net Rationale:Display of a standardized and approved use notification before granting
access to the operating system ensures privacy and security notification
verbiage used is consistent with applicable federal laws, Executive Orders,
directives, policies, regulations, standards, and guidance.
Proper permissions will ensure that only root user can modify the banner. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/issue.net
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Test for existence /etc/issue.net
ansible.builtin.stat:
path: /etc/issue.net
register: file_exists
tags:
- CCE-91357-4
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.8
- configure_strategy
- file_permissions_etc_issue_net
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xws,o-xwt on /etc/issue.net
ansible.builtin.file:
path: /etc/issue.net
mode: u-xs,g-xws,o-xwt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91357-4
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.8
- configure_strategy
- file_permissions_etc_issue_net
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify permissions on Message of the Day Banner
[ref]rule
To properly set the permissions of /etc/motd, run the command:
$ sudo chmod 0644 /etc/motd Rationale:Display of a standardized and approved use notification before granting
access to the operating system ensures privacy and security notification
verbiage used is consistent with applicable federal laws, Executive Orders,
directives, policies, regulations, standards, and guidance.
Proper permissions will ensure that only root user can modify the banner. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/motd
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Test for existence /etc/motd
ansible.builtin.stat:
path: /etc/motd
register: file_exists
tags:
- CCE-91351-7
- configure_strategy
- file_permissions_etc_motd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xws,o-xwt on /etc/motd
ansible.builtin.file:
path: /etc/motd
mode: u-xs,g-xws,o-xwt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91351-7
- configure_strategy
- file_permissions_etc_motd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Protect Accounts by Configuring PAM
[ref]groupPAM, or Pluggable Authentication Modules, is a system
which implements modular authentication for Linux programs. PAM provides
a flexible and configurable architecture for authentication, and it should be configured
to minimize exposure to unnecessary risk. This section contains
guidance on how to accomplish that.
PAM is implemented as a set of shared objects which are
loaded and invoked whenever an application wishes to authenticate a
user. Typically, the application must be running as root in order
to take advantage of PAM, because PAM's modules often need to be able
to access sensitive stores of account information, such as /etc/shadow.
Traditional privileged network listeners
(e.g. sshd) or SUID programs (e.g. sudo) already meet this
requirement. An SUID root application, userhelper, is provided so
that programs which are not SUID or privileged themselves can still
take advantage of PAM.
PAM looks in the directory /etc/pam.d for
application-specific configuration information. For instance, if
the program login attempts to authenticate a user, then PAM's
libraries follow the instructions in the file /etc/pam.d/login
to determine what actions should be taken.
One very important file in /etc/pam.d is
/etc/pam.d/system-auth. This file, which is included by
many other PAM configuration files, defines 'default' system authentication
measures. Modifying this file is a good way to make far-reaching
authentication changes, for instance when implementing a
centralized authentication service. Warning:
Be careful when making changes to PAM's configuration files.
The syntax for these files is complex, and modifications can
have unexpected consequences. The default configurations shipped
with applications should be sufficient for most users. |
| contains 13 rules |
Set Lockouts for Failed Password Attempts
[ref]groupThe pam_faillock PAM module provides the capability to
lock out user accounts after a number of failed login attempts. Its
documentation is available in
/usr/share/doc/pam-VERSION/txts/README.pam_faillock.
Warning:
Locking out user accounts presents the
risk of a denial-of-service attack. The lockout policy
must weigh whether the risk of such a
denial-of-service attack outweighs the benefits of thwarting
password guessing attacks. |
| contains 4 rules |
Limit Password Reuse
[ref]ruleDo not allow users to reuse recent passwords. This can be
accomplished by using the remember option for the
pam_pwhistory PAM modules.
In the file /etc/pam.d/common-password, make sure the parameters
remember and use_authtok are present, and that the value
for the remember parameter is 5 or greater. For example:
password requisite pam_pwhistory.so ...existing_options... remember=5 use_authtok
The profile requirement is 5 passwords.Rationale:Preventing reuse of previous passwords helps ensure that a compromised password is not reused by a user. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q pam; }; then
declare -a VALUES=()
declare -a VALUE_NAMES=()
declare -a ARGS=()
declare -a NEW_ARGS=()
declare -a DEL_ARGS=()
var_password_pam_remember='5'
VALUES+=("$var_password_pam_remember")
VALUE_NAMES+=("remember")
ARGS+=("")
NEW_ARGS+=("")
VALUES+=("")
VALUE_NAMES+=("")
ARGS+=("use_authtok")
NEW_ARGS+=("use_authtok")
for idx in "${!VALUES[@]}"
do
if [ -e "/etc/pam.d/common-password" ] ; then
valueRegex="${VALUES[$idx]}" defaultValue="${VALUES[$idx]}"
# non-empty values need to be preceded by an equals sign
[ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
# add an equals sign to non-empty values
[ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"
# fix the value for 'option' if one exists but does not match 'valueRegex'
if grep -q -P "^\\s*password\\s+requisite\\s+pam_pwhistory.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-password" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_pwhistory.so(\\s.+)?\\s)${VALUE_NAMES[$idx]}=[^[:space:]]*/\\1${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
# add 'option=default' if option is not set
elif grep -q -E "^\\s*password\\s+requisite\\s+pam_pwhistory.so" < "/etc/pam.d/common-password" &&
grep -E "^\\s*password\\s+requisite\\s+pam_pwhistory.so" < "/etc/pam.d/common-password" | grep -q -E -v "\\s${VALUE_NAMES[$idx]}(=|\\s|\$)" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_pwhistory.so[^\\n]*)/\\1 ${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
# add a new entry if none exists
elif ! grep -q -P "^\\s*password\\s+requisite\\s+pam_pwhistory.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}${valueRegex}(\\s|\$)" < "/etc/pam.d/common-password" ; then
echo "password requisite pam_pwhistory.so ${VALUE_NAMES[$idx]}${defaultValue}" >> "/etc/pam.d/common-password"
fi
else
echo "/etc/pam.d/common-password doesn't exist" >&2
fi
done
for idx in "${!ARGS[@]}"
do
if ! grep -q -P "^\s*password\s+requisite\s+pam_pwhistory.so.*\s+${ARGS[$idx]}\s*$" /etc/pam.d/common-password ; then
sed --follow-symlinks -i -E -e "s/^\\s*password\\s+requisite\\s+pam_pwhistory.so.*\$/& ${NEW_ARGS[$idx]}/" /etc/pam.d/common-password
if [ -n "${DEL_ARGS[$idx]}" ]; then
sed --follow-symlinks -i -E -e "s/\s+${DEL_ARGS[$idx]}\S+\s+/ /g" /etc/pam.d/common-password
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91398-8
- accounts_password_pam_pwhistory_remember
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_password_pam_remember # promote to variable
set_fact:
var_password_pam_remember: !!str 5
tags:
- always
- name: Set control_flag fact
ansible.builtin.set_fact:
control_flag: requisite
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
tags:
- CCE-91398-8
- accounts_password_pam_pwhistory_remember
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check to see if 'pam_pwhistory.so' module is configured in '/etc/pam.d/common-password'
ansible.builtin.shell: |
set -o pipefail
grep -E '^\s*password\s+\S+\s+pam_pwhistory.so' /etc/pam.d/common-password || true
register: check_pam_module_result
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
tags:
- CCE-91398-8
- accounts_password_pam_pwhistory_remember
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure 'pam_pwhistory.so' module in '/etc/pam.d/common-password'
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
line: password requisite pam_pwhistory.so
state: present
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
- check_pam_module_result.stdout is defined and '"pam_pwhistory.so" not in check_pam_module_result.stdout'
tags:
- CCE-91398-8
- accounts_password_pam_pwhistory_remember
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure 'pam_pwhistory.so' module has conforming control flag
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+)\S+(\s+pam_pwhistory.so\s+.*)
line: \g<1>requisite\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
- control_flag|length
tags:
- CCE-91398-8
- accounts_password_pam_pwhistory_remember
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure "pam_pwhistory.so" module has argument "remember={{ var_password_pam_remember
}}"
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+requisite\s+pam_pwhistory.so(?:\s+\S+)*\s+remember=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
line: \g<1>{{ var_password_pam_remember }}\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
tags:
- CCE-91398-8
- accounts_password_pam_pwhistory_remember
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check the presence of "remember" argument in "pam_pwhistory.so" module
ansible.builtin.shell: |
set -o pipefail
grep -E '^\s*password\s+requisite\s+pam_pwhistory.so.*\s+remember(=|\s|\s*$)' /etc/pam.d/common-password || true
register: check_pam_module_argument_result
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
tags:
- CCE-91398-8
- accounts_password_pam_pwhistory_remember
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Add "remember" argument to "pam_pwhistory.so" module
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+requisite\s+pam_pwhistory.so)((\s+\S+)*\s*(\\)*$)
line: \g<1> remember={{ var_password_pam_remember }}\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
- check_pam_module_argument_result is not skipped and '"remember" not in check_pam_module_argument_result.stdout'
tags:
- CCE-91398-8
- accounts_password_pam_pwhistory_remember
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Set argument_value fact
ansible.builtin.set_fact:
argument_value: ''
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
tags:
- CCE-91398-8
- accounts_password_pam_pwhistory_remember
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure "pam_pwhistory.so" module has argument "use_authtok"
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+requisite\s+pam_pwhistory.so(?:\s+\S+)*\s+use_authtok=)(?!)\S*((\s+\S+)*\s*\\*\s*)$
line: \g<1>\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
- argument_value|length
tags:
- CCE-91398-8
- accounts_password_pam_pwhistory_remember
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check the presence of "use_authtok" argument in "pam_pwhistory.so" module
ansible.builtin.shell: |
set -o pipefail
grep -E '^\s*password\s+requisite\s+pam_pwhistory.so.*\s+use_authtok(=|\s|\s*$)' /etc/pam.d/common-password || true
register: check_pam_module_argument_result
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
tags:
- CCE-91398-8
- accounts_password_pam_pwhistory_remember
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Add "use_authtok" argument to "pam_pwhistory.so" module
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+requisite\s+pam_pwhistory.so)((\s+\S+)*\s*(\\)*$)
line: \g<1> use_authtok\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
- check_pam_module_argument_result is not skipped and '"use_authtok" not in check_pam_module_argument_result.stdout'
tags:
- CCE-91398-8
- accounts_password_pam_pwhistory_remember
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Lock Accounts After Failed Password Attempts
[ref]ruleThis rule configures the system to lock out accounts after a number of incorrect login attempts
using pam_faillock.so.
pam_faillock.so module requires multiple entries in pam files. These entries must be carefully
defined to work as expected.
Ensure that the file /etc/security/faillock.conf contains the following entry:
deny = <count>
Where count should be less than or equal to
5 and greater than 0.
In order to avoid errors when manually editing these files, it is
recommended to use the appropriate tools, such as authselect or authconfig,
depending on the OS version. Warning:
If the system relies on authselect tool to manage PAM settings, the remediation
will also use authselect tool. However, if any manual modification was made in
PAM files, the authselect integrity check will fail and the remediation will be
aborted in order to preserve intentional changes. In this case, an informative message will
be shown in the remediation report.
If the system supports the /etc/security/faillock.conf file, the pam_faillock
parameters should be defined in faillock.conf file. Rationale:By limiting the number of failed logon attempts, the risk of unauthorized system access via
user password guessing, also known as brute-forcing, is reduced. Limits are imposed by locking
the account. Identifiers:
CCE-85842-3 References:
1, 12, 15, 16, 5.5.3, DSS05.04, DSS05.10, DSS06.10, 3.1.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(a), PR.AC-7, FIA_AFL.1, Req-8.1.6, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, R31, SLES-15-600450030, 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, 8.3.4, 8.3 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q pam; }; then
var_accounts_passwords_pam_faillock_deny='5'
if [ -f /usr/bin/authselect ]; then
if ! authselect check; then
echo "
authselect integrity check failed. Remediation aborted!
This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
It is not recommended to manually edit the PAM files when authselect tool is available.
In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
exit 1
fi
authselect enable-feature with-faillock
authselect apply-changes -b
else
pam_file="/etc/pam.d/common-auth"
if ! grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*$' "$pam_file" ; then
# insert before pam_unix.so
sed -i --follow-symlinks '/^auth.*required.*pam_unix\.so.*/i auth required pam_faillock.so preauth' "$pam_file"
fi
if ! grep -qE '^\s*auth\s+\[default=die\]\s+pam_faillock\.so\s+authfail.*$' "$pam_file" ; then
num_lines=$(sed -n 's/^\s*auth.*success=\([1-9]\).*pam_unix\.so.*/\1/p' "$pam_file")
if [ ! -z "$num_lines" ]; then
# Add pam_faillock (authfail) module below pam_unix, skipping N-1 lines, where N is
# the number of jumps in the pam_unix success=N statement. Ignore commented and empty lines.
append_position=$(cat -n "${pam_file}" \
| grep -P "^\s+\d+\s+auth\s+.*$" \
| grep -w "pam_unix.so" -A $(( num_lines - 1 )) \
| tail -n 1 | cut -f 1 | tr -d ' '
)
sed -i --follow-symlinks ''${append_position}'a auth [default=die] pam_faillock.so authfail' "$pam_file"
else
sed -i --follow-symlinks '/^auth.*pam_unix\.so.*/a auth [default=die] pam_faillock.so authfail' "$pam_file"
fi
fi
if ! grep -qE '^\s*auth\s+sufficient\s+pam_faillock\.so\s+authsucc.*$' "$pam_file" ; then
sed -i --follow-symlinks '/^auth.*pam_faillock\.so.*authfail.*/a auth sufficient pam_faillock.so authsucc' "$pam_file"
fi
pam_file="/etc/pam.d/common-account"
if ! grep -qE '^\s*account\s+required\s+pam_faillock\.so.*$' "$pam_file" ; then
echo 'account required pam_faillock.so' >> "$pam_file"
fi
fi
AUTH_FILES=("/etc/pam.d/common-auth")
SKIP_FAILLOCK_CHECK=true
FAILLOCK_CONF="/etc/security/faillock.conf"
if [ -f $FAILLOCK_CONF ] || [ "$SKIP_FAILLOCK_CHECK" = "true" ]; then
regex="^\s*deny\s*="
line="deny = $var_accounts_passwords_pam_faillock_deny"
if ! grep -q $regex $FAILLOCK_CONF; then
echo $line >> $FAILLOCK_CONF
else
sed -i --follow-symlinks 's|^\s*\(deny\s*=\s*\)\(\S\+\)|\1'"$var_accounts_passwords_pam_faillock_deny"'|g' $FAILLOCK_CONF
fi
for pam_file in "${AUTH_FILES[@]}"
do
if [ -e "$pam_file" ] ; then
PAM_FILE_PATH="$pam_file"
if [ -f /usr/bin/authselect ]; then
if ! authselect check; then
echo "
authselect integrity check failed. Remediation aborted!
This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
It is not recommended to manually edit the PAM files when authselect tool is available.
In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
exit 1
fi
CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
# If not already in use, a custom profile is created preserving the enabled features.
if [[ ! $CURRENT_PROFILE == custom/* ]]; then
ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
# The "local" profile does not contain essential security features required by multiple Benchmarks.
# If currently used, it is replaced by "sssd", which is the best option in this case.
if [[ $CURRENT_PROFILE == local ]]; then
CURRENT_PROFILE="sssd"
fi
authselect create-profile hardening -b $CURRENT_PROFILE
CURRENT_PROFILE="custom/hardening"
authselect apply-changes -b --backup=before-hardening-custom-profile
authselect select $CURRENT_PROFILE
for feature in $ENABLED_FEATURES; do
authselect enable-feature $feature;
done
authselect apply-changes -b --backup=after-hardening-custom-profile
fi
PAM_FILE_NAME=$(basename "$pam_file")
PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"
authselect apply-changes -b
fi
if grep -qP "^\s*auth\s.*\bpam_faillock.so\s.*\bdeny\b" "$PAM_FILE_PATH"; then
sed -i -E --follow-symlinks "s/(.*auth.*pam_faillock.so.*)\bdeny\b=?[[:alnum:]]*(.*)/\1\2/g" "$PAM_FILE_PATH"
fi
if [ -f /usr/bin/authselect ]; then
authselect apply-changes -b
fi
else
echo "$pam_file was not found" >&2
fi
done
else
for pam_file in "${AUTH_FILES[@]}"
do
if ! grep -qE '^\s*auth.*pam_faillock\.so\s+(preauth|authfail).*deny' "$pam_file"; then
sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*preauth.*/ s/$/ deny='"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*authfail.*/ s/$/ deny='"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
else
sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*preauth.*\)\('"deny"'=\)\S\+\b\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_deny"'\3/' "$pam_file"
sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*authfail.*\)\('"deny"'=\)\S\+\b\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_deny"'\3/' "$pam_file"
fi
done
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Configure the root Account for Failed Password Attempts
[ref]ruleThis rule configures the system to lock out the root account after a number of
incorrect login attempts using pam_faillock.so.
pam_faillock.so module requires multiple entries in pam files. These entries must be carefully
defined to work as expected. In order to avoid errors when manually editing these files, it is
recommended to use the appropriate tools, such as authselect or authconfig,
depending on the OS version. Warning:
If the system relies on authselect tool to manage PAM settings, the remediation
will also use authselect tool. However, if any manual modification was made in
PAM files, the authselect integrity check will fail and the remediation will be
aborted in order to preserve intentional changes. In this case, an informative message will
be shown in the remediation report.
If the system supports the /etc/security/faillock.conf file, the pam_faillock
parameters should be defined in faillock.conf file. Rationale:By limiting the number of failed logon attempts, the risk of unauthorized system access via
user password guessing, also known as brute-forcing, is reduced. Limits are imposed by locking
the account. Identifiers:
CCE-91171-9 References:
1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(b), IA-5(c), PR.AC-7, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, R31, SLES-15-600450060, 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q pam; }; then
if [ -f /usr/bin/authselect ]; then
if ! authselect check; then
echo "
authselect integrity check failed. Remediation aborted!
This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
It is not recommended to manually edit the PAM files when authselect tool is available.
In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
exit 1
fi
authselect enable-feature with-faillock
authselect apply-changes -b
else
pam_file="/etc/pam.d/common-auth"
if ! grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*$' "$pam_file" ; then
# insert before pam_unix.so
sed -i --follow-symlinks '/^auth.*required.*pam_unix\.so.*/i auth required pam_faillock.so preauth' "$pam_file"
fi
if ! grep -qE '^\s*auth\s+\[default=die\]\s+pam_faillock\.so\s+authfail.*$' "$pam_file" ; then
num_lines=$(sed -n 's/^\s*auth.*success=\([1-9]\).*pam_unix\.so.*/\1/p' "$pam_file")
if [ ! -z "$num_lines" ]; then
# Add pam_faillock (authfail) module below pam_unix, skipping N-1 lines, where N is
# the number of jumps in the pam_unix success=N statement. Ignore commented and empty lines.
append_position=$(cat -n "${pam_file}" \
| grep -P "^\s+\d+\s+auth\s+.*$" \
| grep -w "pam_unix.so" -A $(( num_lines - 1 )) \
| tail -n 1 | cut -f 1 | tr -d ' '
)
sed -i --follow-symlinks ''${append_position}'a auth [default=die] pam_faillock.so authfail' "$pam_file"
else
sed -i --follow-symlinks '/^auth.*pam_unix\.so.*/a auth [default=die] pam_faillock.so authfail' "$pam_file"
fi
fi
if ! grep -qE '^\s*auth\s+sufficient\s+pam_faillock\.so\s+authsucc.*$' "$pam_file" ; then
sed -i --follow-symlinks '/^auth.*pam_faillock\.so.*authfail.*/a auth sufficient pam_faillock.so authsucc' "$pam_file"
fi
pam_file="/etc/pam.d/common-account"
if ! grep -qE '^\s*account\s+required\s+pam_faillock\.so.*$' "$pam_file" ; then
echo 'account required pam_faillock.so' >> "$pam_file"
fi
fi
AUTH_FILES=("/etc/pam.d/common-auth")
SKIP_FAILLOCK_CHECK=true
FAILLOCK_CONF="/etc/security/faillock.conf"
if [ -f $FAILLOCK_CONF ] || [ "$SKIP_FAILLOCK_CHECK" = "true" ]; then
regex="^\s*even_deny_root"
line="even_deny_root"
if ! grep -q $regex $FAILLOCK_CONF; then
echo $line >> $FAILLOCK_CONF
fi
for pam_file in "${AUTH_FILES[@]}"
do
if [ -e "$pam_file" ] ; then
PAM_FILE_PATH="$pam_file"
if [ -f /usr/bin/authselect ]; then
if ! authselect check; then
echo "
authselect integrity check failed. Remediation aborted!
This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
It is not recommended to manually edit the PAM files when authselect tool is available.
In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
exit 1
fi
CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
# If not already in use, a custom profile is created preserving the enabled features.
if [[ ! $CURRENT_PROFILE == custom/* ]]; then
ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
# The "local" profile does not contain essential security features required by multiple Benchmarks.
# If currently used, it is replaced by "sssd", which is the best option in this case.
if [[ $CURRENT_PROFILE == local ]]; then
CURRENT_PROFILE="sssd"
fi
authselect create-profile hardening -b $CURRENT_PROFILE
CURRENT_PROFILE="custom/hardening"
authselect apply-changes -b --backup=before-hardening-custom-profile
authselect select $CURRENT_PROFILE
for feature in $ENABLED_FEATURES; do
authselect enable-feature $feature;
done
authselect apply-changes -b --backup=after-hardening-custom-profile
fi
PAM_FILE_NAME=$(basename "$pam_file")
PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"
authselect apply-changes -b
fi
if grep -qP "^\s*auth\s.*\bpam_faillock.so\s.*\beven_deny_root\b" "$PAM_FILE_PATH"; then
sed -i -E --follow-symlinks "s/(.*auth.*pam_faillock.so.*)\beven_deny_root\b=?[[:alnum:]]*(.*)/\1\2/g" "$PAM_FILE_PATH"
fi
if [ -f /usr/bin/authselect ]; then
authselect apply-changes -b
fi
else
echo "$pam_file was not found" >&2
fi
done
else
for pam_file in "${AUTH_FILES[@]}"
do
if ! grep -qE '^\s*auth.*pam_faillock\.so\s+(preauth|authfail).*even_deny_root' "$pam_file"; then
sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*preauth.*/ s/$/ even_deny_root/' "$pam_file"
sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*authfail.*/ s/$/ even_deny_root/' "$pam_file"
fi
done
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Set Lockout Time for Failed Password Attempts
[ref]ruleThis rule configures the system to lock out accounts during a specified time period after a
number of incorrect login attempts using pam_faillock.so.
Ensure that the file /etc/security/faillock.conf contains the following entry:
unlock_time=<interval-in-seconds> where
interval-in-seconds is 900 or greater.
pam_faillock.so module requires multiple entries in pam files. These entries must be carefully
defined to work as expected. In order to avoid any errors when manually editing these files,
it is recommended to use the appropriate tools, such as authselect or authconfig,
depending on the OS version.
If unlock_time is set to 0, manual intervention by an administrator is required
to unlock a user. This should be done using the faillock tool. Warning:
If the system supports the new /etc/security/faillock.conf file but the
pam_faillock.so parameters are defined directly in /etc/pam.d/system-auth and
/etc/pam.d/password-auth, the remediation will migrate the unlock_time parameter
to /etc/security/faillock.conf to ensure compatibility with authselect tool.
The parameters deny and fail_interval, if used, also have to be migrated
by their respective remediation. Warning:
If the system relies on authselect tool to manage PAM settings, the remediation
will also use authselect tool. However, if any manual modification was made in
PAM files, the authselect integrity check will fail and the remediation will be
aborted in order to preserve intentional changes. In this case, an informative message will
be shown in the remediation report.
If the system supports the /etc/security/faillock.conf file, the pam_faillock
parameters should be defined in faillock.conf file. Rationale:By limiting the number of failed logon attempts the risk of unauthorized system
access via user password guessing, otherwise known as brute-forcing, is reduced.
Limits are imposed by locking the account. Identifiers:
CCE-85841-5 References:
1, 12, 15, 16, 5.5.3, DSS05.04, DSS05.10, DSS06.10, 3.1.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(b), PR.AC-7, FIA_AFL.1, Req-8.1.7, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, R31, SLES-15-600450045, 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, 8.3.4, 8.3 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q pam; }; then
var_accounts_passwords_pam_faillock_unlock_time='900'
if [ -f /usr/bin/authselect ]; then
if ! authselect check; then
echo "
authselect integrity check failed. Remediation aborted!
This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
It is not recommended to manually edit the PAM files when authselect tool is available.
In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
exit 1
fi
authselect enable-feature with-faillock
authselect apply-changes -b
else
pam_file="/etc/pam.d/common-auth"
if ! grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+preauth.*$' "$pam_file" ; then
# insert before pam_unix.so
sed -i --follow-symlinks '/^auth.*required.*pam_unix\.so.*/i auth required pam_faillock.so preauth' "$pam_file"
fi
if ! grep -qE '^\s*auth\s+\[default=die\]\s+pam_faillock\.so\s+authfail.*$' "$pam_file" ; then
num_lines=$(sed -n 's/^\s*auth.*success=\([1-9]\).*pam_unix\.so.*/\1/p' "$pam_file")
if [ ! -z "$num_lines" ]; then
# Add pam_faillock (authfail) module below pam_unix, skipping N-1 lines, where N is
# the number of jumps in the pam_unix success=N statement. Ignore commented and empty lines.
append_position=$(cat -n "${pam_file}" \
| grep -P "^\s+\d+\s+auth\s+.*$" \
| grep -w "pam_unix.so" -A $(( num_lines - 1 )) \
| tail -n 1 | cut -f 1 | tr -d ' '
)
sed -i --follow-symlinks ''${append_position}'a auth [default=die] pam_faillock.so authfail' "$pam_file"
else
sed -i --follow-symlinks '/^auth.*pam_unix\.so.*/a auth [default=die] pam_faillock.so authfail' "$pam_file"
fi
fi
if ! grep -qE '^\s*auth\s+sufficient\s+pam_faillock\.so\s+authsucc.*$' "$pam_file" ; then
sed -i --follow-symlinks '/^auth.*pam_faillock\.so.*authfail.*/a auth sufficient pam_faillock.so authsucc' "$pam_file"
fi
pam_file="/etc/pam.d/common-account"
if ! grep -qE '^\s*account\s+required\s+pam_faillock\.so.*$' "$pam_file" ; then
echo 'account required pam_faillock.so' >> "$pam_file"
fi
fi
AUTH_FILES=("/etc/pam.d/common-auth")
SKIP_FAILLOCK_CHECK=true
FAILLOCK_CONF="/etc/security/faillock.conf"
if [ -f $FAILLOCK_CONF ] || [ "$SKIP_FAILLOCK_CHECK" = "true" ]; then
regex="^\s*unlock_time\s*="
line="unlock_time = $var_accounts_passwords_pam_faillock_unlock_time"
if ! grep -q $regex $FAILLOCK_CONF; then
echo $line >> $FAILLOCK_CONF
else
sed -i --follow-symlinks 's|^\s*\(unlock_time\s*=\s*\)\(\S\+\)|\1'"$var_accounts_passwords_pam_faillock_unlock_time"'|g' $FAILLOCK_CONF
fi
for pam_file in "${AUTH_FILES[@]}"
do
if [ -e "$pam_file" ] ; then
PAM_FILE_PATH="$pam_file"
if [ -f /usr/bin/authselect ]; then
if ! authselect check; then
echo "
authselect integrity check failed. Remediation aborted!
This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
It is not recommended to manually edit the PAM files when authselect tool is available.
In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
exit 1
fi
CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
# If not already in use, a custom profile is created preserving the enabled features.
if [[ ! $CURRENT_PROFILE == custom/* ]]; then
ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
# The "local" profile does not contain essential security features required by multiple Benchmarks.
# If currently used, it is replaced by "sssd", which is the best option in this case.
if [[ $CURRENT_PROFILE == local ]]; then
CURRENT_PROFILE="sssd"
fi
authselect create-profile hardening -b $CURRENT_PROFILE
CURRENT_PROFILE="custom/hardening"
authselect apply-changes -b --backup=before-hardening-custom-profile
authselect select $CURRENT_PROFILE
for feature in $ENABLED_FEATURES; do
authselect enable-feature $feature;
done
authselect apply-changes -b --backup=after-hardening-custom-profile
fi
PAM_FILE_NAME=$(basename "$pam_file")
PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"
authselect apply-changes -b
fi
if grep -qP "^\s*auth\s.*\bpam_faillock.so\s.*\bunlock_time\b" "$PAM_FILE_PATH"; then
sed -i -E --follow-symlinks "s/(.*auth.*pam_faillock.so.*)\bunlock_time\b=?[[:alnum:]]*(.*)/\1\2/g" "$PAM_FILE_PATH"
fi
if [ -f /usr/bin/authselect ]; then
authselect apply-changes -b
fi
else
echo "$pam_file was not found" >&2
fi
done
else
for pam_file in "${AUTH_FILES[@]}"
do
if ! grep -qE '^\s*auth.*pam_faillock\.so\s+(preauth|authfail).*unlock_time' "$pam_file"; then
sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*preauth.*/ s/$/ unlock_time='"$var_accounts_passwords_pam_faillock_unlock_time"'/' "$pam_file"
sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*authfail.*/ s/$/ unlock_time='"$var_accounts_passwords_pam_faillock_unlock_time"'/' "$pam_file"
else
sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*preauth.*\)\('"unlock_time"'=\)\S\+\b\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_unlock_time"'\3/' "$pam_file"
sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*authfail.*\)\('"unlock_time"'=\)\S\+\b\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_unlock_time"'\3/' "$pam_file"
fi
done
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Set Password Quality Requirements
[ref]groupThe default pam_pwquality PAM module provides strength
checking for passwords. It performs a number of checks, such as
making sure passwords are not similar to dictionary words, are of
at least a certain length, are not the previous password reversed,
and are not simply a change of case from the previous password. It
can also require passwords to be in certain character classes. The
pam_pwquality module is the preferred way of configuring
password requirements.
The man pages pam_pwquality(8)
provide information on the capabilities and configuration of
each. |
| contains 6 rules |
Set Password Quality Requirements, if using
pam_cracklib
[ref]groupThe pam_cracklib PAM module can be configured to meet
requirements for a variety of policies.
For example, to configure pam_cracklib to require at least one uppercase
character, lowercase character, digit, and other (special)
character, locate the following line in /etc/pam.d/system-auth:
password requisite pam_cracklib.so try_first_pass retry=3
and then alter it to read:
password required pam_cracklib.so try_first_pass retry=3 maxrepeat=3 minlen=14 dcredit=-1 ucredit=-1 ocredit=-1 lcredit=-1 difok=4
If no such line exists, add one as the first line of the password section in /etc/pam.d/system-auth.
The arguments can be modified to ensure compliance with
your organization's security policy. Discussion of each parameter follows.Warning:
Note that the password quality requirements are not enforced for the
root account for some reason. |
| contains 5 rules |
Set Password Strength Minimum Digit Characters
[ref]ruleThe pam_cracklib module's dcredit parameter controls requirements
for usage of digits in a password. When set to a negative number, any
password will be required to contain that many digits. When set to a
positive number, pam_cracklib will grant +1 additional length credit for
each digit. Add dcredit=-1 after pam_cracklib.so to require use of
a digit in passwords. Rationale:Requiring digits makes password guessing attacks more difficult by ensuring
a larger search space. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
declare -a VALUES=()
declare -a VALUE_NAMES=()
declare -a ARGS=()
declare -a NEW_ARGS=()
declare -a DEL_ARGS=()
var_password_pam_dcredit='-1'
VALUES+=("$var_password_pam_dcredit")
VALUE_NAMES+=("dcredit")
ARGS+=("")
NEW_ARGS+=("")
for idx in "${!VALUES[@]}"
do
if [ -e "/etc/pam.d/common-password" ] ; then
valueRegex="${VALUES[$idx]}" defaultValue="${VALUES[$idx]}"
# non-empty values need to be preceded by an equals sign
[ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
# add an equals sign to non-empty values
[ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"
# fix the value for 'option' if one exists but does not match 'valueRegex'
if grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-password" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s)${VALUE_NAMES[$idx]}=[^[:space:]]*/\\1${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
# add 'option=default' if option is not set
elif grep -q -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" &&
grep -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" | grep -q -E -v "\\s${VALUE_NAMES[$idx]}(=|\\s|\$)" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so[^\\n]*)/\\1 ${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
# add a new entry if none exists
elif ! grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}${valueRegex}(\\s|\$)" < "/etc/pam.d/common-password" ; then
echo "password requisite pam_cracklib.so ${VALUE_NAMES[$idx]}${defaultValue}" >> "/etc/pam.d/common-password"
fi
else
echo "/etc/pam.d/common-password doesn't exist" >&2
fi
done
for idx in "${!ARGS[@]}"
do
if ! grep -q -P "^\s*password\s+requisite\s+pam_cracklib.so.*\s+${ARGS[$idx]}\s*$" /etc/pam.d/common-password ; then
sed --follow-symlinks -i -E -e "s/^\\s*password\\s+requisite\\s+pam_cracklib.so.*\$/& ${NEW_ARGS[$idx]}/" /etc/pam.d/common-password
if [ -n "${DEL_ARGS[$idx]}" ]; then
sed --follow-symlinks -i -E -e "s/\s+${DEL_ARGS[$idx]}\S+\s+/ /g" /etc/pam.d/common-password
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85564-3
- DISA-STIG-SLES-15-020150
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_dcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_password_pam_dcredit # promote to variable
set_fact:
var_password_pam_dcredit: !!str -1
tags:
- always
- name: Set control_flag fact
ansible.builtin.set_fact:
control_flag: requisite
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85564-3
- DISA-STIG-SLES-15-020150
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_dcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check to see if 'pam_cracklib.so' module is configured in '/etc/pam.d/common-password'
ansible.builtin.shell: |
set -o pipefail
grep -E '^\s*password\s+\S+\s+pam_cracklib.so' /etc/pam.d/common-password || true
register: check_pam_module_result
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85564-3
- DISA-STIG-SLES-15-020150
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_dcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure 'pam_cracklib.so' module in '/etc/pam.d/common-password'
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
line: password requisite pam_cracklib.so
state: present
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- check_pam_module_result.stdout is defined and '"pam_cracklib.so" not in check_pam_module_result.stdout'
tags:
- CCE-85564-3
- DISA-STIG-SLES-15-020150
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_dcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure 'pam_cracklib.so' module has conforming control flag
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+)\S+(\s+pam_cracklib.so\s+.*)
line: \g<1>requisite\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- control_flag|length
tags:
- CCE-85564-3
- DISA-STIG-SLES-15-020150
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_dcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure "pam_cracklib.so" module has argument "dcredit={{ var_password_pam_dcredit
}}"
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+requisite\s+pam_cracklib.so(?:\s+\S+)*\s+dcredit=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
line: \g<1>{{ var_password_pam_dcredit }}\g<2>
backrefs: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85564-3
- DISA-STIG-SLES-15-020150
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_dcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check the presence of "dcredit" argument in "pam_cracklib.so" module
ansible.builtin.shell: |
set -o pipefail
grep -E '^\s*password\s+requisite\s+pam_cracklib.so.*\s+dcredit(=|\s|\s*$)' /etc/pam.d/common-password || true
register: check_pam_module_argument_result
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85564-3
- DISA-STIG-SLES-15-020150
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_dcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Add "dcredit" argument to "pam_cracklib.so" module
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+requisite\s+pam_cracklib.so)((\s+\S+)*\s*(\\)*$)
line: \g<1> dcredit={{ var_password_pam_dcredit }}\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- check_pam_module_argument_result is not skipped and '"dcredit" not in check_pam_module_argument_result.stdout'
tags:
- CCE-85564-3
- DISA-STIG-SLES-15-020150
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_dcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Set Password Strength Minimum Different Characters
[ref]ruleThe pam_cracklib module's difok parameter controls requirements for
usage of different characters during a password change. The number of
changed characters refers to the number of changes required with respect to
the total number of positions in the current password. In other words,
characters may be the same within the two passwords; however, the positions
of the like characters must be different.
Make sure the difok parameter for the pam_cracklib module is
configured to greater than or equal to 2. Rationale:Requiring a minimum number of different characters during password changes
ensures that newly changed passwords should not resemble previously
compromised ones. Note that passwords which are changed on compromised
systems will still be compromised, however. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
declare -a VALUES=()
declare -a VALUE_NAMES=()
declare -a ARGS=()
declare -a NEW_ARGS=()
declare -a DEL_ARGS=()
var_password_pam_difok='2'
VALUES+=("$var_password_pam_difok")
VALUE_NAMES+=("difok")
ARGS+=("")
NEW_ARGS+=("")
for idx in "${!VALUES[@]}"
do
if [ -e "/etc/pam.d/common-password" ] ; then
valueRegex="${VALUES[$idx]}" defaultValue="${VALUES[$idx]}"
# non-empty values need to be preceded by an equals sign
[ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
# add an equals sign to non-empty values
[ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"
# fix the value for 'option' if one exists but does not match 'valueRegex'
if grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-password" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s)${VALUE_NAMES[$idx]}=[^[:space:]]*/\\1${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
# add 'option=default' if option is not set
elif grep -q -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" &&
grep -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" | grep -q -E -v "\\s${VALUE_NAMES[$idx]}(=|\\s|\$)" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so[^\\n]*)/\\1 ${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
# add a new entry if none exists
elif ! grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}${valueRegex}(\\s|\$)" < "/etc/pam.d/common-password" ; then
echo "password requisite pam_cracklib.so ${VALUE_NAMES[$idx]}${defaultValue}" >> "/etc/pam.d/common-password"
fi
else
echo "/etc/pam.d/common-password doesn't exist" >&2
fi
done
for idx in "${!ARGS[@]}"
do
if ! grep -q -P "^\s*password\s+requisite\s+pam_cracklib.so.*\s+${ARGS[$idx]}\s*$" /etc/pam.d/common-password ; then
sed --follow-symlinks -i -E -e "s/^\\s*password\\s+requisite\\s+pam_cracklib.so.*\$/& ${NEW_ARGS[$idx]}/" /etc/pam.d/common-password
if [ -n "${DEL_ARGS[$idx]}" ]; then
sed --follow-symlinks -i -E -e "s/\s+${DEL_ARGS[$idx]}\S+\s+/ /g" /etc/pam.d/common-password
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85677-3
- DISA-STIG-SLES-15-020160
- NIST-800-53-IA-5(1)(b)
- NIST-800-53-IA-5(1).1(v)
- cracklib_accounts_password_pam_difok
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_password_pam_difok # promote to variable
set_fact:
var_password_pam_difok: !!str 2
tags:
- always
- name: Set control_flag fact
ansible.builtin.set_fact:
control_flag: requisite
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85677-3
- DISA-STIG-SLES-15-020160
- NIST-800-53-IA-5(1)(b)
- NIST-800-53-IA-5(1).1(v)
- cracklib_accounts_password_pam_difok
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check to see if 'pam_cracklib.so' module is configured in '/etc/pam.d/common-password'
ansible.builtin.shell: |
set -o pipefail
grep -E '^\s*password\s+\S+\s+pam_cracklib.so' /etc/pam.d/common-password || true
register: check_pam_module_result
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85677-3
- DISA-STIG-SLES-15-020160
- NIST-800-53-IA-5(1)(b)
- NIST-800-53-IA-5(1).1(v)
- cracklib_accounts_password_pam_difok
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure 'pam_cracklib.so' module in '/etc/pam.d/common-password'
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
line: password requisite pam_cracklib.so
state: present
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- check_pam_module_result.stdout is defined and '"pam_cracklib.so" not in check_pam_module_result.stdout'
tags:
- CCE-85677-3
- DISA-STIG-SLES-15-020160
- NIST-800-53-IA-5(1)(b)
- NIST-800-53-IA-5(1).1(v)
- cracklib_accounts_password_pam_difok
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure 'pam_cracklib.so' module has conforming control flag
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+)\S+(\s+pam_cracklib.so\s+.*)
line: \g<1>requisite\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- control_flag|length
tags:
- CCE-85677-3
- DISA-STIG-SLES-15-020160
- NIST-800-53-IA-5(1)(b)
- NIST-800-53-IA-5(1).1(v)
- cracklib_accounts_password_pam_difok
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure "pam_cracklib.so" module has argument "difok={{ var_password_pam_difok
}}"
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+requisite\s+pam_cracklib.so(?:\s+\S+)*\s+difok=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
line: \g<1>{{ var_password_pam_difok }}\g<2>
backrefs: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85677-3
- DISA-STIG-SLES-15-020160
- NIST-800-53-IA-5(1)(b)
- NIST-800-53-IA-5(1).1(v)
- cracklib_accounts_password_pam_difok
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check the presence of "difok" argument in "pam_cracklib.so" module
ansible.builtin.shell: |
set -o pipefail
grep -E '^\s*password\s+requisite\s+pam_cracklib.so.*\s+difok(=|\s|\s*$)' /etc/pam.d/common-password || true
register: check_pam_module_argument_result
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85677-3
- DISA-STIG-SLES-15-020160
- NIST-800-53-IA-5(1)(b)
- NIST-800-53-IA-5(1).1(v)
- cracklib_accounts_password_pam_difok
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Add "difok" argument to "pam_cracklib.so" module
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+requisite\s+pam_cracklib.so)((\s+\S+)*\s*(\\)*$)
line: \g<1> difok={{ var_password_pam_difok }}\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- check_pam_module_argument_result is not skipped and '"difok" not in check_pam_module_argument_result.stdout'
tags:
- CCE-85677-3
- DISA-STIG-SLES-15-020160
- NIST-800-53-IA-5(1)(b)
- NIST-800-53-IA-5(1).1(v)
- cracklib_accounts_password_pam_difok
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Set Password Strength Minimum Lowercase Characters
[ref]ruleThe pam_cracklib module's lcredit= parameter controls requirements
for usage of lowercase letters in a password. When set to a negative
number, any password will be required to contain that many lowercase
characters. When set to a positive number, pam_cracklib will grant +1
additional length credit for each lowercase character.
Add lcredit=-1 after pam_cracklib.so to require use of a
lowercase character in passwords. Rationale:Requiring a minimum number of lowercase characters makes password guessing
attacks more difficult by ensuring a larger search space. Identifiers:
CCE-85676-5 References:
IA-5(1)(a), IA-5(1).1(v), Req-8.2.3, SRG-OS-000070-GPOS-00038, SLES-15-020140, 5.3.1, R31, SLES-15-600450120, 8.3.6, 8.3, SV-234883r1009622_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
declare -a VALUES=()
declare -a VALUE_NAMES=()
declare -a ARGS=()
declare -a NEW_ARGS=()
declare -a DEL_ARGS=()
var_password_pam_lcredit='-1'
VALUES+=("$var_password_pam_lcredit")
VALUE_NAMES+=("lcredit")
ARGS+=("")
NEW_ARGS+=("")
for idx in "${!VALUES[@]}"
do
if [ -e "/etc/pam.d/common-password" ] ; then
valueRegex="${VALUES[$idx]}" defaultValue="${VALUES[$idx]}"
# non-empty values need to be preceded by an equals sign
[ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
# add an equals sign to non-empty values
[ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"
# fix the value for 'option' if one exists but does not match 'valueRegex'
if grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-password" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s)${VALUE_NAMES[$idx]}=[^[:space:]]*/\\1${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
# add 'option=default' if option is not set
elif grep -q -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" &&
grep -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" | grep -q -E -v "\\s${VALUE_NAMES[$idx]}(=|\\s|\$)" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so[^\\n]*)/\\1 ${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
# add a new entry if none exists
elif ! grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}${valueRegex}(\\s|\$)" < "/etc/pam.d/common-password" ; then
echo "password requisite pam_cracklib.so ${VALUE_NAMES[$idx]}${defaultValue}" >> "/etc/pam.d/common-password"
fi
else
echo "/etc/pam.d/common-password doesn't exist" >&2
fi
done
for idx in "${!ARGS[@]}"
do
if ! grep -q -P "^\s*password\s+requisite\s+pam_cracklib.so.*\s+${ARGS[$idx]}\s*$" /etc/pam.d/common-password ; then
sed --follow-symlinks -i -E -e "s/^\\s*password\\s+requisite\\s+pam_cracklib.so.*\$/& ${NEW_ARGS[$idx]}/" /etc/pam.d/common-password
if [ -n "${DEL_ARGS[$idx]}" ]; then
sed --follow-symlinks -i -E -e "s/\s+${DEL_ARGS[$idx]}\S+\s+/ /g" /etc/pam.d/common-password
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85676-5
- DISA-STIG-SLES-15-020140
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_lcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_password_pam_lcredit # promote to variable
set_fact:
var_password_pam_lcredit: !!str -1
tags:
- always
- name: Set control_flag fact
ansible.builtin.set_fact:
control_flag: requisite
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85676-5
- DISA-STIG-SLES-15-020140
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_lcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check to see if 'pam_cracklib.so' module is configured in '/etc/pam.d/common-password'
ansible.builtin.shell: |
set -o pipefail
grep -E '^\s*password\s+\S+\s+pam_cracklib.so' /etc/pam.d/common-password || true
register: check_pam_module_result
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85676-5
- DISA-STIG-SLES-15-020140
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_lcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure 'pam_cracklib.so' module in '/etc/pam.d/common-password'
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
line: password requisite pam_cracklib.so
state: present
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- check_pam_module_result.stdout is defined and '"pam_cracklib.so" not in check_pam_module_result.stdout'
tags:
- CCE-85676-5
- DISA-STIG-SLES-15-020140
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_lcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure 'pam_cracklib.so' module has conforming control flag
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+)\S+(\s+pam_cracklib.so\s+.*)
line: \g<1>requisite\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- control_flag|length
tags:
- CCE-85676-5
- DISA-STIG-SLES-15-020140
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_lcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure "pam_cracklib.so" module has argument "lcredit={{ var_password_pam_lcredit
}}"
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+requisite\s+pam_cracklib.so(?:\s+\S+)*\s+lcredit=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
line: \g<1>{{ var_password_pam_lcredit }}\g<2>
backrefs: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85676-5
- DISA-STIG-SLES-15-020140
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_lcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check the presence of "lcredit" argument in "pam_cracklib.so" module
ansible.builtin.shell: |
set -o pipefail
grep -E '^\s*password\s+requisite\s+pam_cracklib.so.*\s+lcredit(=|\s|\s*$)' /etc/pam.d/common-password || true
register: check_pam_module_argument_result
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85676-5
- DISA-STIG-SLES-15-020140
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_lcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Add "lcredit" argument to "pam_cracklib.so" module
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+requisite\s+pam_cracklib.so)((\s+\S+)*\s*(\\)*$)
line: \g<1> lcredit={{ var_password_pam_lcredit }}\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- check_pam_module_argument_result is not skipped and '"lcredit" not in check_pam_module_argument_result.stdout'
tags:
- CCE-85676-5
- DISA-STIG-SLES-15-020140
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- cracklib_accounts_password_pam_lcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Set Password Strength Minimum Special Characters
[ref]ruleThe pam_cracklib module's ocredit= parameter controls requirements
for usage of special (or ``other'') characters in a password. When set to a
negative number, any password will be required to contain that many special
characters. When set to a positive number, pam_cracklib will grant +1
additional length credit for each special character.
Make sure the ocredit parameter for the pam_cracklib module is
set to less than or equal to -1. For example, ocredit=-1. Rationale:Requiring a minimum number of special characters makes password guessing
attacks more difficult by ensuring a larger search space. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
declare -a VALUES=()
declare -a VALUE_NAMES=()
declare -a ARGS=()
declare -a NEW_ARGS=()
declare -a DEL_ARGS=()
var_password_pam_ocredit='-1'
VALUES+=("$var_password_pam_ocredit")
VALUE_NAMES+=("ocredit")
ARGS+=("")
NEW_ARGS+=("")
for idx in "${!VALUES[@]}"
do
if [ -e "/etc/pam.d/common-password" ] ; then
valueRegex="${VALUES[$idx]}" defaultValue="${VALUES[$idx]}"
# non-empty values need to be preceded by an equals sign
[ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
# add an equals sign to non-empty values
[ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"
# fix the value for 'option' if one exists but does not match 'valueRegex'
if grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-password" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s)${VALUE_NAMES[$idx]}=[^[:space:]]*/\\1${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
# add 'option=default' if option is not set
elif grep -q -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" &&
grep -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" | grep -q -E -v "\\s${VALUE_NAMES[$idx]}(=|\\s|\$)" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so[^\\n]*)/\\1 ${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
# add a new entry if none exists
elif ! grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}${valueRegex}(\\s|\$)" < "/etc/pam.d/common-password" ; then
echo "password requisite pam_cracklib.so ${VALUE_NAMES[$idx]}${defaultValue}" >> "/etc/pam.d/common-password"
fi
else
echo "/etc/pam.d/common-password doesn't exist" >&2
fi
done
for idx in "${!ARGS[@]}"
do
if ! grep -q -P "^\s*password\s+requisite\s+pam_cracklib.so.*\s+${ARGS[$idx]}\s*$" /etc/pam.d/common-password ; then
sed --follow-symlinks -i -E -e "s/^\\s*password\\s+requisite\\s+pam_cracklib.so.*\$/& ${NEW_ARGS[$idx]}/" /etc/pam.d/common-password
if [ -n "${DEL_ARGS[$idx]}" ]; then
sed --follow-symlinks -i -E -e "s/\s+${DEL_ARGS[$idx]}\S+\s+/ /g" /etc/pam.d/common-password
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85574-2
- DISA-STIG-SLES-15-020270
- NIST-800-53-IA-5(a)
- NIST-800-53-IA-5(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ocredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_password_pam_ocredit # promote to variable
set_fact:
var_password_pam_ocredit: !!str -1
tags:
- always
- name: Set control_flag fact
ansible.builtin.set_fact:
control_flag: requisite
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85574-2
- DISA-STIG-SLES-15-020270
- NIST-800-53-IA-5(a)
- NIST-800-53-IA-5(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ocredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check to see if 'pam_cracklib.so' module is configured in '/etc/pam.d/common-password'
ansible.builtin.shell: |
set -o pipefail
grep -E '^\s*password\s+\S+\s+pam_cracklib.so' /etc/pam.d/common-password || true
register: check_pam_module_result
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85574-2
- DISA-STIG-SLES-15-020270
- NIST-800-53-IA-5(a)
- NIST-800-53-IA-5(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ocredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure 'pam_cracklib.so' module in '/etc/pam.d/common-password'
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
line: password requisite pam_cracklib.so
state: present
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- check_pam_module_result.stdout is defined and '"pam_cracklib.so" not in check_pam_module_result.stdout'
tags:
- CCE-85574-2
- DISA-STIG-SLES-15-020270
- NIST-800-53-IA-5(a)
- NIST-800-53-IA-5(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ocredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure 'pam_cracklib.so' module has conforming control flag
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+)\S+(\s+pam_cracklib.so\s+.*)
line: \g<1>requisite\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- control_flag|length
tags:
- CCE-85574-2
- DISA-STIG-SLES-15-020270
- NIST-800-53-IA-5(a)
- NIST-800-53-IA-5(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ocredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure "pam_cracklib.so" module has argument "ocredit={{ var_password_pam_ocredit
}}"
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+requisite\s+pam_cracklib.so(?:\s+\S+)*\s+ocredit=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
line: \g<1>{{ var_password_pam_ocredit }}\g<2>
backrefs: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85574-2
- DISA-STIG-SLES-15-020270
- NIST-800-53-IA-5(a)
- NIST-800-53-IA-5(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ocredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check the presence of "ocredit" argument in "pam_cracklib.so" module
ansible.builtin.shell: |
set -o pipefail
grep -E '^\s*password\s+requisite\s+pam_cracklib.so.*\s+ocredit(=|\s|\s*$)' /etc/pam.d/common-password || true
register: check_pam_module_argument_result
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85574-2
- DISA-STIG-SLES-15-020270
- NIST-800-53-IA-5(a)
- NIST-800-53-IA-5(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ocredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Add "ocredit" argument to "pam_cracklib.so" module
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+requisite\s+pam_cracklib.so)((\s+\S+)*\s*(\\)*$)
line: \g<1> ocredit={{ var_password_pam_ocredit }}\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- check_pam_module_argument_result is not skipped and '"ocredit" not in check_pam_module_argument_result.stdout'
tags:
- CCE-85574-2
- DISA-STIG-SLES-15-020270
- NIST-800-53-IA-5(a)
- NIST-800-53-IA-5(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ocredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Set Password Strength Minimum Uppercase Characters
[ref]ruleThe pam_cracklib module's ucredit= parameter controls requirements
for usage of uppercase letters in a password. When set to a negative
number, any password will be required to contain that many uppercase
characters. When set to a positive number, pam_cracklib will grant +1
additional length credit for each uppercase character.
Add ucredit=-1 after pam_cracklib.so to require use of an upper
case character in passwords. Rationale:Requiring a minimum number of uppercase characters makes password guessing
attacks more difficult by ensuring a larger search space. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
declare -a VALUES=()
declare -a VALUE_NAMES=()
declare -a ARGS=()
declare -a NEW_ARGS=()
declare -a DEL_ARGS=()
var_password_pam_ucredit='-1'
VALUES+=("$var_password_pam_ucredit")
VALUE_NAMES+=("ucredit")
ARGS+=("")
NEW_ARGS+=("")
for idx in "${!VALUES[@]}"
do
if [ -e "/etc/pam.d/common-password" ] ; then
valueRegex="${VALUES[$idx]}" defaultValue="${VALUES[$idx]}"
# non-empty values need to be preceded by an equals sign
[ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
# add an equals sign to non-empty values
[ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"
# fix the value for 'option' if one exists but does not match 'valueRegex'
if grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-password" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s)${VALUE_NAMES[$idx]}=[^[:space:]]*/\\1${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
# add 'option=default' if option is not set
elif grep -q -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" &&
grep -E "^\\s*password\\s+requisite\\s+pam_cracklib.so" < "/etc/pam.d/common-password" | grep -q -E -v "\\s${VALUE_NAMES[$idx]}(=|\\s|\$)" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*password\\s+requisite\\s+pam_cracklib.so[^\\n]*)/\\1 ${VALUE_NAMES[$idx]}${defaultValue}/" "/etc/pam.d/common-password"
# add a new entry if none exists
elif ! grep -q -P "^\\s*password\\s+requisite\\s+pam_cracklib.so(\\s.+)?\\s+${VALUE_NAMES[$idx]}${valueRegex}(\\s|\$)" < "/etc/pam.d/common-password" ; then
echo "password requisite pam_cracklib.so ${VALUE_NAMES[$idx]}${defaultValue}" >> "/etc/pam.d/common-password"
fi
else
echo "/etc/pam.d/common-password doesn't exist" >&2
fi
done
for idx in "${!ARGS[@]}"
do
if ! grep -q -P "^\s*password\s+requisite\s+pam_cracklib.so.*\s+${ARGS[$idx]}\s*$" /etc/pam.d/common-password ; then
sed --follow-symlinks -i -E -e "s/^\\s*password\\s+requisite\\s+pam_cracklib.so.*\$/& ${NEW_ARGS[$idx]}/" /etc/pam.d/common-password
if [ -n "${DEL_ARGS[$idx]}" ]; then
sed --follow-symlinks -i -E -e "s/\s+${DEL_ARGS[$idx]}\S+\s+/ /g" /etc/pam.d/common-password
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85675-7
- DISA-STIG-SLES-15-020130
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ucredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_password_pam_ucredit # promote to variable
set_fact:
var_password_pam_ucredit: !!str -1
tags:
- always
- name: Set control_flag fact
ansible.builtin.set_fact:
control_flag: requisite
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85675-7
- DISA-STIG-SLES-15-020130
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ucredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check to see if 'pam_cracklib.so' module is configured in '/etc/pam.d/common-password'
ansible.builtin.shell: |
set -o pipefail
grep -E '^\s*password\s+\S+\s+pam_cracklib.so' /etc/pam.d/common-password || true
register: check_pam_module_result
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85675-7
- DISA-STIG-SLES-15-020130
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ucredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure 'pam_cracklib.so' module in '/etc/pam.d/common-password'
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
line: password requisite pam_cracklib.so
state: present
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- check_pam_module_result.stdout is defined and '"pam_cracklib.so" not in check_pam_module_result.stdout'
tags:
- CCE-85675-7
- DISA-STIG-SLES-15-020130
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ucredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure 'pam_cracklib.so' module has conforming control flag
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+)\S+(\s+pam_cracklib.so\s+.*)
line: \g<1>requisite\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- control_flag|length
tags:
- CCE-85675-7
- DISA-STIG-SLES-15-020130
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ucredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure "pam_cracklib.so" module has argument "ucredit={{ var_password_pam_ucredit
}}"
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+requisite\s+pam_cracklib.so(?:\s+\S+)*\s+ucredit=)(?:\S+)((\s+\S+)*\s*\\*\s*)$
line: \g<1>{{ var_password_pam_ucredit }}\g<2>
backrefs: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85675-7
- DISA-STIG-SLES-15-020130
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ucredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check the presence of "ucredit" argument in "pam_cracklib.so" module
ansible.builtin.shell: |
set -o pipefail
grep -E '^\s*password\s+requisite\s+pam_cracklib.so.*\s+ucredit(=|\s|\s*$)' /etc/pam.d/common-password || true
register: check_pam_module_argument_result
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85675-7
- DISA-STIG-SLES-15-020130
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ucredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Add "ucredit" argument to "pam_cracklib.so" module
ansible.builtin.lineinfile:
path: /etc/pam.d/common-password
regexp: ^(\s*password\s+requisite\s+pam_cracklib.so)((\s+\S+)*\s*(\\)*$)
line: \g<1> ucredit={{ var_password_pam_ucredit }}\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- check_pam_module_argument_result is not skipped and '"ucredit" not in check_pam_module_argument_result.stdout'
tags:
- CCE-85675-7
- DISA-STIG-SLES-15-020130
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(1).1(v)
- PCI-DSS-Req-8.2.3
- cracklib_accounts_password_pam_ucredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Set Password Quality Requirements with pam_pwquality
[ref]groupThe pam_pwquality PAM module can be configured to meet
requirements for a variety of policies.
For example, to configure pam_pwquality to require at least one uppercase
character, lowercase character, digit, and other (special)
character, make sure that pam_pwquality exists in /etc/pam.d/system-auth:
password requisite pam_pwquality.so try_first_pass local_users_only retry=3 authtok_type=
If no such line exists, add one as the first line of the password section in /etc/pam.d/system-auth.
Next, modify the settings in /etc/security/pwquality.conf to match the following:
difok = 4
minlen = 14
dcredit = -1
ucredit = -1
lcredit = -1
ocredit = -1
maxrepeat = 3
The arguments can be modified to ensure compliance with
your organization's security policy. Discussion of each parameter follows. |
| contains 1 rule |
Ensure PAM Enforces Password Requirements - Minimum Length
[ref]ruleThe pam_pwquality module's minlen parameter controls requirements for
minimum characters required in a password. Add minlen=14
after pam_pwquality to set minimum password length requirements. Rationale:The shorter the password, the lower the number of possible combinations
that need to be tested before the password is compromised.
Password complexity, or strength, is a measure of the effectiveness of a
password in resisting attempts at guessing and brute-force attacks.
Password length is one factor of several that helps to determine strength
and how long it takes to crack a password. Use of more characters in a password
helps to exponentially increase the time and/or resources required to
compromise the password. Identifiers:
CCE-85785-4 References:
1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, Req-8.2.3, SRG-OS-000078-GPOS-00046, 5.3.1, R31, R68, SLES-15-600450105, 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, 8.3.6, 8.3 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q libpwquality; }; then
var_password_pam_minlen='14'
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^minlen")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_minlen"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^minlen\\>" "/etc/security/pwquality.conf"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^minlen\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
else
if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
fi
cce="CCE-85785-4"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/security/pwquality.conf" >> "/etc/security/pwquality.conf"
printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85785-4
- CJIS-5.6.2.1.1
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(4)
- NIST-800-53-IA-5(c)
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- accounts_password_pam_minlen
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_password_pam_minlen # promote to variable
set_fact:
var_password_pam_minlen: !!str 14
tags:
- always
- name: Ensure PAM Enforces Password Requirements - Minimum Length - Ensure PAM variable
minlen is set accordingly
ansible.builtin.lineinfile:
create: true
dest: /etc/security/pwquality.conf
regexp: ^#?\s*minlen
line: minlen = {{ var_password_pam_minlen }}
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"libpwquality" in ansible_facts.packages'
tags:
- CCE-85785-4
- CJIS-5.6.2.1.1
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(4)
- NIST-800-53-IA-5(c)
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.6
- accounts_password_pam_minlen
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Set Password Hashing Algorithm
[ref]groupThe system's default algorithm for storing password hashes in
/etc/shadow is SHA-512. This can be configured in several
locations. |
| contains 3 rules |
Set Password Hashing Algorithm in /etc/login.defs
[ref]ruleIn /etc/login.defs, add or update the following line to ensure the system will use
SHA512 as the hashing algorithm:
ENCRYPT_METHOD SHA512 Rationale:Passwords need to be protected at all times, and encryption is the standard method for
protecting passwords. If passwords are not encrypted, they can be plainly read
(i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm
are no more protected than if they are kept in plain text.
Using a stronger hashing algorithm makes password cracking attacks more difficult. Identifiers:
CCE-83279-0 References:
1, 12, 15, 16, 5, 5.6.2.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.13.11, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(c), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, SRG-OS-000073-GPOS-00041, SLES-15-010260, 5.4.1.1, SLES-15-600600060, 0418, 1055, 1402, 8.3.2, 8.3, SV-234825r971535_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q shadow; }; then
var_password_hashing_algorithm='SHA512'
# Allow multiple algorithms, but choose the first one for remediation
#
var_password_hashing_algorithm="$(echo $var_password_hashing_algorithm | cut -d \| -f 1)"
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^ENCRYPT_METHOD")
# shellcheck disable=SC2059
printf -v formatted_output "%s %s" "$stripped_key" "$var_password_hashing_algorithm"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^ENCRYPT_METHOD\\>" "/etc/login.defs"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^ENCRYPT_METHOD\\>.*/$escaped_formatted_output/gi" "/etc/login.defs"
else
if [[ -s "/etc/login.defs" ]] && [[ -n "$(tail -c 1 -- "/etc/login.defs" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/login.defs"
fi
cce="CCE-83279-0"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/login.defs" >> "/etc/login.defs"
printf '%s\n' "$formatted_output" >> "/etc/login.defs"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83279-0
- CJIS-5.6.2.2
- DISA-STIG-SLES-15-010260
- NIST-800-171-3.13.11
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(c)
- NIST-800-53-IA-5(c)
- PCI-DSS-Req-8.2.1
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.2
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- set_password_hashing_algorithm_logindefs
- name: XCCDF Value var_password_hashing_algorithm # promote to variable
set_fact:
var_password_hashing_algorithm: !!str SHA512
tags:
- always
- name: Set Password Hashing Algorithm in /etc/login.defs
ansible.builtin.lineinfile:
dest: /etc/login.defs
regexp: ^#?ENCRYPT_METHOD
line: ENCRYPT_METHOD {{ var_password_hashing_algorithm.split('|')[0] }}
state: present
create: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"shadow" in ansible_facts.packages'
tags:
- CCE-83279-0
- CJIS-5.6.2.2
- DISA-STIG-SLES-15-010260
- NIST-800-171-3.13.11
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(c)
- NIST-800-53-IA-5(c)
- PCI-DSS-Req-8.2.1
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.2
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- set_password_hashing_algorithm_logindefs
|
Set PAM''s Password Hashing Algorithm - password-auth
[ref]ruleThe PAM system service can be configured to only store encrypted representations of passwords.
In /etc/pam.d/password-auth, the password section of the file controls which
PAM modules to execute during a password change.
Set the pam_unix.so module in the password section to include the option
sha512 and no other hashing
algorithms as shown below:
password sufficient pam_unix.so sha512 other arguments...
This will help ensure that new passwords for local users will be stored using the
sha512 algorithm.Warning:
The hashing algorithms to be used with pam_unix.so are defined with independent module
options. There are at least 7 possible algorithms and likely more algorithms will be
introduced along the time. Due the the number of options and its possible combinations,
the use of multiple hashing algorithm options may bring unexpected behaviors to the
system. For this reason the check will pass only when one hashing algorithm option is
defined and is aligned to the "var_password_hashing_algorithm_pam" variable. The
remediation will ensure the correct option and remove any other extra hashing algorithm
option. Rationale:Passwords need to be protected at all times, and encryption is the standard method for
protecting passwords. If passwords are not encrypted, they can be plainly read
(i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm
are no more protected than if they are kept in plain text.
This setting ensures user and group account administration utilities are configured to store
only encrypted representations of passwords. Additionally, the crypt_style
configuration option in /etc/libuser.conf ensures the use of a strong hashing
algorithm that makes password cracking attacks more difficult. Identifiers:
CCE-92607-1 References:
1, 12, 15, 16, 5, 5.6.2.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.13.11, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(c), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061, SLES-15-600450255, 0418, 1055, 1402 |
Set PAM''s Password Hashing Algorithm
[ref]ruleThe PAM system service can be configured to only store encrypted representations of passwords.
In "/etc/pam.d/common-password", the password section of the file controls which
PAM modules to execute during a password change.
Set the pam_unix.so module in the password section to include the option
sha512 and no other hashing
algorithms as shown below:
password required pam_unix.so sha512 other arguments...
This will help ensure that new passwords for local users will be stored using the
sha512 algorithm.Warning:
The hashing algorithms to be used with pam_unix.so are defined with independent module
options. There are at least 7 possible algorithms and likely more algorithms will be
introduced along the time. Due the the number of options and its possible combinations,
the use of multiple hashing algorithm options may bring unexpected behaviors to the
system. For this reason the check will pass only when one hashing algorithm option is
defined and is aligned to the "var_password_hashing_algorithm_pam" variable. The
remediation will ensure the correct option and remove any other extra hashing algorithm
option. Rationale:Passwords need to be protected at all times, and encryption is the standard method for
protecting passwords. If passwords are not encrypted, they can be plainly read
(i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm
are no more protected than if they are kept in plain text.
This setting ensures user and group account administration utilities are configured to store
only encrypted representations of passwords. Additionally, the crypt_style
configuration option in /etc/libuser.conf ensures the use of a strong hashing
algorithm that makes password cracking attacks more difficult. Identifiers:
CCE-85565-0 References:
1, 12, 15, 16, 5, 5.6.2.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.13.11, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(c), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061, SLES-15-020170, R68, SLES-15-600450255, 0418, 1055, 1402, 8.3.2, 8.3, SV-234886r1009625_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q pam; }; then
var_password_hashing_algorithm_pam='sha512'
PAM_FILE_PATH="/etc/pam.d/common-password"
# Ensure all the hashing algorithm option is removed.
declare -a HASHING_ALGORITHMS_OPTIONS=("sha512" "yescrypt" "gost_yescrypt" "blowfish" "sha256" "md5" "bigcrypt")
for hash_option in "${HASHING_ALGORITHMS_OPTIONS[@]}"; do
if grep -qP "^\s*password\s+.*\s+pam_unix.so\s+.*\b$hash_option\b" "$PAM_FILE_PATH"; then
if [ -e "$PAM_FILE_PATH" ] ; then
PAM_FILE_PATH="$PAM_FILE_PATH"
if [ -f /usr/bin/authselect ]; then
if ! authselect check; then
echo "
authselect integrity check failed. Remediation aborted!
This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
It is not recommended to manually edit the PAM files when authselect tool is available.
In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
exit 1
fi
CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
# If not already in use, a custom profile is created preserving the enabled features.
if [[ ! $CURRENT_PROFILE == custom/* ]]; then
ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
# The "local" profile does not contain essential security features required by multiple Benchmarks.
# If currently used, it is replaced by "sssd", which is the best option in this case.
if [[ $CURRENT_PROFILE == local ]]; then
CURRENT_PROFILE="sssd"
fi
authselect create-profile hardening -b $CURRENT_PROFILE
CURRENT_PROFILE="custom/hardening"
authselect apply-changes -b --backup=before-hardening-custom-profile
authselect select $CURRENT_PROFILE
for feature in $ENABLED_FEATURES; do
authselect enable-feature $feature;
done
authselect apply-changes -b --backup=after-hardening-custom-profile
fi
PAM_FILE_NAME=$(basename "$PAM_FILE_PATH")
PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"
authselect apply-changes -b
fi
if grep -qP "^\s*password\s+.*\s+pam_unix.so\s.*\b$hash_option\b" "$PAM_FILE_PATH"; then
sed -i -E --follow-symlinks "s/(.*password.*.*.*pam_unix.so.*)\b$hash_option\b=?[[:alnum:]]*(.*)/\1\2/g" "$PAM_FILE_PATH"
fi
if [ -f /usr/bin/authselect ]; then
authselect apply-changes -b
fi
else
echo "$PAM_FILE_PATH was not found" >&2
fi
fi
done
if [ -e "$PAM_FILE_PATH" ] ; then
PAM_FILE_PATH="$PAM_FILE_PATH"
if [ -f /usr/bin/authselect ]; then
if ! authselect check; then
echo "
authselect integrity check failed. Remediation aborted!
This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
It is not recommended to manually edit the PAM files when authselect tool is available.
In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
exit 1
fi
CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
# If not already in use, a custom profile is created preserving the enabled features.
if [[ ! $CURRENT_PROFILE == custom/* ]]; then
ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
# The "local" profile does not contain essential security features required by multiple Benchmarks.
# If currently used, it is replaced by "sssd", which is the best option in this case.
if [[ $CURRENT_PROFILE == local ]]; then
CURRENT_PROFILE="sssd"
fi
authselect create-profile hardening -b $CURRENT_PROFILE
CURRENT_PROFILE="custom/hardening"
authselect apply-changes -b --backup=before-hardening-custom-profile
authselect select $CURRENT_PROFILE
for feature in $ENABLED_FEATURES; do
authselect enable-feature $feature;
done
authselect apply-changes -b --backup=after-hardening-custom-profile
fi
PAM_FILE_NAME=$(basename "$PAM_FILE_PATH")
PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"
authselect apply-changes -b
fi
if ! grep -qP "^\s*password\s+required\s+pam_unix.so\s*.*" "$PAM_FILE_PATH"; then
# Line matching group + control + module was not found. Check group + module.
if [ "$(grep -cP '^\s*password\s+.*\s+pam_unix.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
# The control is updated only if one single line matches.
sed -i -E --follow-symlinks "s/^(\s*password\s+).*(\bpam_unix.so.*)/\1required \2/" "$PAM_FILE_PATH"
else
echo "password required pam_unix.so" >> "$PAM_FILE_PATH"
fi
fi
# Check the option
if ! grep -qP "^\s*password\s+required\s+pam_unix.so\s*.*\s$var_password_hashing_algorithm_pam\b" "$PAM_FILE_PATH"; then
sed -i -E --follow-symlinks "/\s*password\s+required\s+pam_unix.so.*/ s/$/ $var_password_hashing_algorithm_pam/" "$PAM_FILE_PATH"
fi
if [ -f /usr/bin/authselect ]; then
authselect apply-changes -b
fi
else
echo "$PAM_FILE_PATH was not found" >&2
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85565-0
- CJIS-5.6.2.2
- DISA-STIG-SLES-15-020170
- NIST-800-171-3.13.11
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(c)
- NIST-800-53-IA-5(c)
- PCI-DSS-Req-8.2.1
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- set_password_hashing_algorithm_systemauth
- name: XCCDF Value var_password_hashing_algorithm_pam # promote to variable
set_fact:
var_password_hashing_algorithm_pam: !!str sha512
tags:
- always
- name: Set PAM's Password Hashing Algorithm - Check if /etc/pam.d/common-password
file is present
ansible.builtin.stat:
path: /etc/pam.d/common-password
register: result_pam_file_present
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
tags:
- CCE-85565-0
- CJIS-5.6.2.2
- DISA-STIG-SLES-15-020170
- NIST-800-171-3.13.11
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(c)
- NIST-800-53-IA-5(c)
- PCI-DSS-Req-8.2.1
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- set_password_hashing_algorithm_systemauth
- name: Set PAM's Password Hashing Algorithm - Check the proper remediation for the
system
block:
- name: Set PAM's Password Hashing Algorithm - Define the PAM file to be edited
as a local fact
ansible.builtin.set_fact:
pam_file_path: /etc/pam.d/common-password
- name: Set PAM's Password Hashing Algorithm - Check if system relies on authselect
tool
ansible.builtin.stat:
path: /usr/bin/authselect
register: result_authselect_present
- name: Set PAM's Password Hashing Algorithm - Ensure authselect custom profile
is used if authselect is present
block:
- name: Set PAM's Password Hashing Algorithm - Check integrity of authselect current
profile
ansible.builtin.command:
cmd: authselect check
register: result_authselect_check_cmd
changed_when: false
check_mode: false
failed_when: false
- name: Set PAM's Password Hashing Algorithm - Informative message based on the
authselect integrity check result
ansible.builtin.assert:
that:
- ansible_check_mode or result_authselect_check_cmd.rc == 0
fail_msg:
- authselect integrity check failed. Remediation aborted!
- This remediation could not be applied because an authselect profile was
not selected or the selected profile is not intact.
- It is not recommended to manually edit the PAM files when authselect tool
is available.
- In cases where the default authselect profile does not cover a specific
demand, a custom authselect profile is recommended.
success_msg:
- authselect integrity check passed
- name: Set PAM's Password Hashing Algorithm - Get authselect current profile
ansible.builtin.shell:
cmd: authselect current -r | awk '{ print $1 }'
register: result_authselect_profile
changed_when: false
when:
- result_authselect_check_cmd is success
- name: Set PAM's Password Hashing Algorithm - Define the current authselect profile
as a local fact
ansible.builtin.set_fact:
authselect_current_profile: '{{ result_authselect_profile.stdout }}'
authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
when:
- result_authselect_profile is not skipped
- result_authselect_profile.stdout is match("custom/")
- name: Set PAM's Password Hashing Algorithm - Define the new authselect custom
profile as a local fact
ansible.builtin.set_fact:
authselect_current_profile: '{{ result_authselect_profile.stdout }}'
authselect_custom_profile: custom/hardening
when:
- result_authselect_profile is not skipped
- result_authselect_profile.stdout is not match("custom/")
- name: Set PAM's Password Hashing Algorithm - Get authselect current features
to also enable them in the custom profile
ansible.builtin.shell:
cmd: authselect current | tail -n+3 | awk '{ print $2 }'
register: result_authselect_features
changed_when: false
check_mode: false
when:
- result_authselect_profile is not skipped
- authselect_current_profile is not match("custom/")
- name: Set PAM's Password Hashing Algorithm - Check if any custom profile with
the same name was already created
ansible.builtin.stat:
path: /etc/authselect/{{ authselect_custom_profile }}
register: result_authselect_custom_profile_present
changed_when: false
when:
- result_authselect_profile is not skipped
- authselect_current_profile is not match("custom/")
- name: Set PAM's Password Hashing Algorithm - Create an authselect custom profile
based on the current profile
ansible.builtin.command:
cmd: authselect create-profile hardening -b {{ authselect_current_profile
}}
when:
- result_authselect_profile is not skipped
- result_authselect_check_cmd is success
- authselect_current_profile is not match("^(custom/|local)")
- not result_authselect_custom_profile_present.stat.exists
- name: Set PAM's Password Hashing Algorithm - Create an authselect custom profile
based on sssd profile
ansible.builtin.command:
cmd: authselect create-profile hardening -b sssd
when:
- result_authselect_profile is not skipped
- result_authselect_check_cmd is success
- authselect_current_profile is match("local")
- not result_authselect_custom_profile_present.stat.exists
- name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
ansible.builtin.command:
cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
when:
- result_authselect_check_cmd is success
- result_authselect_profile is not skipped
- authselect_current_profile is not match("custom/")
- authselect_custom_profile is not match(authselect_current_profile)
- name: Set PAM's Password Hashing Algorithm - Ensure the authselect custom profile
is selected
ansible.builtin.command:
cmd: authselect select {{ authselect_custom_profile }}
register: result_pam_authselect_select_profile
when:
- result_authselect_check_cmd is success
- result_authselect_profile is not skipped
- authselect_current_profile is not match("custom/")
- authselect_custom_profile is not match(authselect_current_profile)
- name: Set PAM's Password Hashing Algorithm - Restore the authselect features
in the custom profile
ansible.builtin.command:
cmd: authselect enable-feature {{ item }}
loop: '{{ result_authselect_features.stdout_lines }}'
register: result_pam_authselect_restore_features
when:
- result_authselect_profile is not skipped
- result_authselect_features is not skipped
- result_pam_authselect_select_profile is not skipped
- name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
ansible.builtin.command:
cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
when:
- result_authselect_check_cmd is success
- result_authselect_profile is not skipped
- result_pam_authselect_restore_features is not skipped
- name: Set PAM's Password Hashing Algorithm - Change the PAM file to be edited
according to the custom authselect profile
ansible.builtin.set_fact:
pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
| basename }}
when:
- authselect_custom_profile is defined
when:
- result_authselect_present.stat.exists
- name: Set PAM's Password Hashing Algorithm - Define a fact for control already
filtered in case filters are used
ansible.builtin.set_fact:
pam_module_control: required
- name: Set PAM's Password Hashing Algorithm - Check if expected PAM module line
is present in {{ pam_file_path }}
ansible.builtin.lineinfile:
path: '{{ pam_file_path }}'
regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_unix.so\s*.*
state: absent
check_mode: true
changed_when: false
register: result_pam_line_present
- name: Set PAM's Password Hashing Algorithm - Include or update the PAM module
line in {{ pam_file_path }}
block:
- name: Set PAM's Password Hashing Algorithm - Check if required PAM module line
is present in {{ pam_file_path }} with different control
ansible.builtin.lineinfile:
path: '{{ pam_file_path }}'
regexp: ^\s*password\s+.*\s+pam_unix.so\s*
state: absent
check_mode: true
changed_when: false
register: result_pam_line_other_control_present
- name: Set PAM's Password Hashing Algorithm - Ensure the correct control for
the required PAM module line in {{ pam_file_path }}
ansible.builtin.replace:
dest: '{{ pam_file_path }}'
regexp: ^(\s*password\s+).*(\bpam_unix.so.*)
replace: \1{{ pam_module_control }} \2
register: result_pam_module_edit
when:
- result_pam_line_other_control_present.found == 1
- name: Set PAM's Password Hashing Algorithm - Ensure the required PAM module
line is included in {{ pam_file_path }}
ansible.builtin.lineinfile:
dest: '{{ pam_file_path }}'
line: password {{ pam_module_control }} pam_unix.so
register: result_pam_module_add
when:
- result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
> 1
- name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
ansible.builtin.command:
cmd: authselect apply-changes -b
when:
- result_authselect_present is defined
- result_authselect_present.stat.exists
- |-
(result_pam_module_add is defined and result_pam_module_add.changed)
or (result_pam_module_edit is defined and result_pam_module_edit.changed)
when:
- result_pam_line_present.found is defined
- result_pam_line_present.found == 0
- name: Set PAM's Password Hashing Algorithm - Define a fact for control already
filtered in case filters are used
ansible.builtin.set_fact:
pam_module_control: required
- name: Set PAM's Password Hashing Algorithm - Check if the required PAM module
option is present in {{ pam_file_path }}
ansible.builtin.lineinfile:
path: '{{ pam_file_path }}'
regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_unix.so\s*.*\s{{
var_password_hashing_algorithm_pam }}\b
state: absent
check_mode: true
changed_when: false
register: result_pam_module_set_password_hashing_algorithm_systemauth_option_present
- name: Set PAM's Password Hashing Algorithm - Ensure the "{{ var_password_hashing_algorithm_pam
}}" PAM option for "pam_unix.so" is included in {{ pam_file_path }}
ansible.builtin.lineinfile:
path: '{{ pam_file_path }}'
backrefs: true
regexp: ^(\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_unix.so.*)
line: \1 {{ var_password_hashing_algorithm_pam }}
state: present
register: result_pam_set_password_hashing_algorithm_systemauth_add
when:
- result_pam_module_set_password_hashing_algorithm_systemauth_option_present.found
is defined
- result_pam_module_set_password_hashing_algorithm_systemauth_option_present.found
== 0
- name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
ansible.builtin.command:
cmd: authselect apply-changes -b
when:
- result_authselect_present.stat.exists
- |-
(result_pam_set_password_hashing_algorithm_systemauth_add is defined and result_pam_set_password_hashing_algorithm_systemauth_add.changed)
or (result_pam_set_password_hashing_algorithm_systemauth_edit is defined and result_pam_set_password_hashing_algorithm_systemauth_edit.changed)
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
- result_pam_file_present.stat.exists
tags:
- CCE-85565-0
- CJIS-5.6.2.2
- DISA-STIG-SLES-15-020170
- NIST-800-171-3.13.11
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(c)
- NIST-800-53-IA-5(c)
- PCI-DSS-Req-8.2.1
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- set_password_hashing_algorithm_systemauth
- name: Set PAM's Password Hashing Algorithm - Check if /etc/pam.d/common-password
File is Present
ansible.builtin.stat:
path: /etc/pam.d/common-password
register: result_pam_file_present
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
tags:
- CCE-85565-0
- CJIS-5.6.2.2
- DISA-STIG-SLES-15-020170
- NIST-800-171-3.13.11
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(c)
- NIST-800-53-IA-5(c)
- PCI-DSS-Req-8.2.1
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- set_password_hashing_algorithm_systemauth
- name: Set PAM's Password Hashing Algorithm - Check The Proper Remediation For The
System
block:
- name: Set PAM's Password Hashing Algorithm - Define the PAM file to be edited
as a local fact
ansible.builtin.set_fact:
pam_file_path: /etc/pam.d/common-password
- name: Set PAM's Password Hashing Algorithm - Check if system relies on authselect
tool
ansible.builtin.stat:
path: /usr/bin/authselect
register: result_authselect_present
- name: Set PAM's Password Hashing Algorithm - Ensure authselect custom profile
is used if authselect is present
block:
- name: Set PAM's Password Hashing Algorithm - Check integrity of authselect current
profile
ansible.builtin.command:
cmd: authselect check
register: result_authselect_check_cmd
changed_when: false
check_mode: false
failed_when: false
- name: Set PAM's Password Hashing Algorithm - Informative message based on the
authselect integrity check result
ansible.builtin.assert:
that:
- ansible_check_mode or result_authselect_check_cmd.rc == 0
fail_msg:
- authselect integrity check failed. Remediation aborted!
- This remediation could not be applied because an authselect profile was
not selected or the selected profile is not intact.
- It is not recommended to manually edit the PAM files when authselect tool
is available.
- In cases where the default authselect profile does not cover a specific
demand, a custom authselect profile is recommended.
success_msg:
- authselect integrity check passed
- name: Set PAM's Password Hashing Algorithm - Get authselect current profile
ansible.builtin.shell:
cmd: authselect current -r | awk '{ print $1 }'
register: result_authselect_profile
changed_when: false
when:
- result_authselect_check_cmd is success
- name: Set PAM's Password Hashing Algorithm - Define the current authselect profile
as a local fact
ansible.builtin.set_fact:
authselect_current_profile: '{{ result_authselect_profile.stdout }}'
authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
when:
- result_authselect_profile is not skipped
- result_authselect_profile.stdout is match("custom/")
- name: Set PAM's Password Hashing Algorithm - Define the new authselect custom
profile as a local fact
ansible.builtin.set_fact:
authselect_current_profile: '{{ result_authselect_profile.stdout }}'
authselect_custom_profile: custom/hardening
when:
- result_authselect_profile is not skipped
- result_authselect_profile.stdout is not match("custom/")
- name: Set PAM's Password Hashing Algorithm - Get authselect current features
to also enable them in the custom profile
ansible.builtin.shell:
cmd: authselect current | tail -n+3 | awk '{ print $2 }'
register: result_authselect_features
changed_when: false
check_mode: false
when:
- result_authselect_profile is not skipped
- authselect_current_profile is not match("custom/")
- name: Set PAM's Password Hashing Algorithm - Check if any custom profile with
the same name was already created
ansible.builtin.stat:
path: /etc/authselect/{{ authselect_custom_profile }}
register: result_authselect_custom_profile_present
changed_when: false
when:
- result_authselect_profile is not skipped
- authselect_current_profile is not match("custom/")
- name: Set PAM's Password Hashing Algorithm - Create an authselect custom profile
based on the current profile
ansible.builtin.command:
cmd: authselect create-profile hardening -b {{ authselect_current_profile
}}
when:
- result_authselect_profile is not skipped
- result_authselect_check_cmd is success
- authselect_current_profile is not match("^(custom/|local)")
- not result_authselect_custom_profile_present.stat.exists
- name: Set PAM's Password Hashing Algorithm - Create an authselect custom profile
based on sssd profile
ansible.builtin.command:
cmd: authselect create-profile hardening -b sssd
when:
- result_authselect_profile is not skipped
- result_authselect_check_cmd is success
- authselect_current_profile is match("local")
- not result_authselect_custom_profile_present.stat.exists
- name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
ansible.builtin.command:
cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
when:
- result_authselect_check_cmd is success
- result_authselect_profile is not skipped
- authselect_current_profile is not match("custom/")
- authselect_custom_profile is not match(authselect_current_profile)
- name: Set PAM's Password Hashing Algorithm - Ensure the authselect custom profile
is selected
ansible.builtin.command:
cmd: authselect select {{ authselect_custom_profile }}
register: result_pam_authselect_select_profile
when:
- result_authselect_check_cmd is success
- result_authselect_profile is not skipped
- authselect_current_profile is not match("custom/")
- authselect_custom_profile is not match(authselect_current_profile)
- name: Set PAM's Password Hashing Algorithm - Restore the authselect features
in the custom profile
ansible.builtin.command:
cmd: authselect enable-feature {{ item }}
loop: '{{ result_authselect_features.stdout_lines }}'
register: result_pam_authselect_restore_features
when:
- result_authselect_profile is not skipped
- result_authselect_features is not skipped
- result_pam_authselect_select_profile is not skipped
- name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
ansible.builtin.command:
cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
when:
- result_authselect_check_cmd is success
- result_authselect_profile is not skipped
- result_pam_authselect_restore_features is not skipped
- name: Set PAM's Password Hashing Algorithm - Change the PAM file to be edited
according to the custom authselect profile
ansible.builtin.set_fact:
pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
| basename }}
when:
- authselect_custom_profile is defined
when:
- result_authselect_present.stat.exists
- name: Set PAM's Password Hashing Algorithm - Check if "{{ pam_file_path }}" File
is Present
ansible.builtin.stat:
path: '{{ pam_file_path }}'
register: pam_file_path_present
- name: Set PAM's Password Hashing Algorithm - Ensure That Only the Correct Hashing
Algorithm Option For pam_unix.so Is Used in {{ pam_file_path }}
ansible.builtin.replace:
dest: '{{ pam_file_path }}'
regexp: (^\s*password.*pam_unix\.so.*)\b{{ item }}\b\s*(.*)
replace: \1\2
when:
- item != var_password_hashing_algorithm_pam
- pam_file_path_present.stat.exists
loop:
- sha512
- yescrypt
- gost_yescrypt
- blowfish
- sha256
- md5
- bigcrypt
register: result_pam_hashing_options_removal
- name: Set PAM's Password Hashing Algorithm - Ensure authselect changes are applied
ansible.builtin.command:
cmd: authselect apply-changes -b
when:
- result_authselect_present.stat.exists
- result_pam_hashing_options_removal is changed
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
- result_pam_file_present.stat.exists
tags:
- CCE-85565-0
- CJIS-5.6.2.2
- DISA-STIG-SLES-15-020170
- NIST-800-171-3.13.11
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(c)
- NIST-800-53-IA-5(c)
- PCI-DSS-Req-8.2.1
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- set_password_hashing_algorithm_systemauth
|
Protect Physical Console Access
[ref]groupIt is impossible to fully protect a system from an
attacker with physical access, so securing the space in which the
system is located should be considered a necessary step. However,
there are some steps which, if taken, make it more difficult for an
attacker to quickly or undetectably modify a system from its
console. |
| contains 4 rules |
Configure Screen Locking
[ref]groupWhen a user must temporarily leave an account
logged-in, screen locking should be employed to prevent passersby
from abusing the account. User education and training is
particularly important for screen locking to be effective, and policies
can be implemented to reinforce this.
Automatic screen locking is only meant as a safeguard for
those cases where a user forgot to lock the screen. |
| contains 4 rules |
Hardware Tokens for Authentication
[ref]groupThe use of hardware tokens such as smart cards for system login
provides stronger, two-factor authentication than using a username and password.
In Red Hat Enterprise Linux servers and workstations, hardware token login
is not enabled by default and must be enabled in the system settings. |
| contains 4 rules |
Install Smart Card Packages For Multifactor Authentication
[ref]ruleConfigure the operating system to implement multifactor authentication by
installing the required package with the following command:
The pam_pkcs11 package can be installed with the following command:
$ sudo zypper install pam_pkcs11
The mozilla-nss package can be installed with the following command:
$ sudo zypper install mozilla-nss
The mozilla-nss-tools package can be installed with the following command:
$ sudo zypper install mozilla-nss-tools
The pcsc-ccid package can be installed with the following command:
$ sudo zypper install pcsc-ccid
The pcsc-lite package can be installed with the following command:
$ sudo zypper install pcsc-lite
The pcsc-tools package can be installed with the following command:
$ sudo zypper install pcsc-tools
The opensc package can be installed with the following command:
$ sudo zypper install opensc Rationale:Using an authentication device, such as a CAC or token that is separate from
the information system, ensures that even if the information system is
compromised, that compromise will not affect credentials stored on the
authentication device.
Multifactor solutions that require devices separate from
information systems gaining access include, for example, hardware tokens
providing time-based or challenge-response authenticators and smart cards
or similar secure authentication devices issued by an organization or identity provider. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { ! ( grep -sqE "^.*\.s390x$" /proc/sys/kernel/osrelease || grep -sqE "^s390x$" /proc/sys/kernel/arch; ); }; then
SMARTCARD_PACKAGES=( "pam_pkcs11" "mozilla-nss" "mozilla-nss-tools" "pcsc-ccid" "pcsc-lite" "pcsc-tools" "opensc")
for PKGNAME in "${SMARTCARD_PACKAGES[@]}"
do
zypper install -y "$PKGNAME"
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83292-3
- DISA-STIG-SLES-15-010460
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.3
- enable_strategy
- install_smartcard_packages
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set smartcard packages fact
ansible.builtin.set_fact:
smartcard_packages:
- pam_pkcs11
- mozilla-nss
- mozilla-nss-tools
- pcsc-ccid
- pcsc-lite
- pcsc-tools
- opensc
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture != "s390x"
tags:
- CCE-83292-3
- DISA-STIG-SLES-15-010460
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.3
- enable_strategy
- install_smartcard_packages
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure {{ smartcard_packages }} are installed
ansible.builtin.package:
name: '{{ smartcard_packages }}'
state: present
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture != "s390x"
tags:
- CCE-83292-3
- DISA-STIG-SLES-15-010460
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.3
- enable_strategy
- install_smartcard_packages
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Configure Smart Card Certificate Authority Validation
[ref]ruleConfigure the operating system to do certificate status checking for PKI
authentication. Modify all of the cert_policy lines in
/etc/pam_pkcs11/pam_pkcs11.conf to include ca like so:
cert_policy = ca, ocsp_on, signature; Rationale:Using an authentication device, such as a CAC or token that is separate from
the information system, ensures that even if the information system is
compromised, that compromise will not affect credentials stored on the
authentication device.
Multifactor solutions that require devices separate from
information systems gaining access include, for example, hardware tokens
providing time-based or challenge-response authenticators and smart cards
or similar secure authentication devices issued by an organization or identity provider. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if rpm -qa pam_pkcs11; then
if grep "^\s*cert_policy" /etc/pam_pkcs11/pam_pkcs11.conf | grep -q "ca"; then
sed -i "/^\s*#/! s/cert_policy.*/cert_policy = ca, ocsp_on, signature;/g" /etc/pam_pkcs11/pam_pkcs11.conf
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83272-5
- DISA-STIG-SLES-15-010170
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- smartcard_configure_ca
- name: Package facts
ansible.builtin.package_facts: null
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83272-5
- DISA-STIG-SLES-15-010170
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- smartcard_configure_ca
- name: Replace 'none' from cert_policy
ansible.builtin.replace:
path: /etc/pam_pkcs11/pam_pkcs11.conf
regexp: (^\s*cert_policy\s*=\s*)none\s*;(\s*$)
replace: \g<1>ocsp_on,ca,signature;\g<2>
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '''pam_pkcs11'' in ansible_facts.packages'
tags:
- CCE-83272-5
- DISA-STIG-SLES-15-010170
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- smartcard_configure_ca
- name: Add 'ca' parameter for cert_policy in /etc/pam_pkcs11/pam_pkcs11.conf
ansible.builtin.replace:
path: /etc/pam_pkcs11/pam_pkcs11.conf
regexp: (^\s*cert_policy\s*=\s*)(?!.*ca)(.*)
replace: \g<1>ca,\g<2>
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '''pam_pkcs11'' in ansible_facts.packages'
tags:
- CCE-83272-5
- DISA-STIG-SLES-15-010170
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- smartcard_configure_ca
|
Configure Smart Card Certificate Status Checking
[ref]ruleConfigure the operating system to do certificate status checking for PKI
authentication. Modify all of the cert_policy lines in
/etc/pam_pkcs11/pam_pkcs11.conf to include ocsp_on like so:
cert_policy = ca, ocsp_on, signature; Rationale:Using an authentication device, such as a CAC or token that is separate from
the information system, ensures that even if the information system is
compromised, that compromise will not affect credentials stored on the
authentication device.
Multifactor solutions that require devices separate from
information systems gaining access include, for example, hardware tokens
providing time-based or challenge-response authenticators and smart cards
or similar secure authentication devices issued by an organization or identity provider. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { ! ( grep -sqE "^.*\.s390x$" /proc/sys/kernel/osrelease || grep -sqE "^s390x$" /proc/sys/kernel/arch; ); }; then
zypper install -y "pam_pkcs11"
if grep "^\s*cert_policy" /etc/pam_pkcs11/pam_pkcs11.conf | grep -qv "ocsp_on"; then
sed -i "/^\s*#/! s/cert_policy.*/cert_policy = ca, ocsp_on, signature;/g" /etc/pam_pkcs11/pam_pkcs11.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83293-1
- DISA-STIG-SLES-15-010470
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- smartcard_configure_cert_checking
- name: Package facts
ansible.builtin.package_facts: null
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture != "s390x"
tags:
- CCE-83293-1
- DISA-STIG-SLES-15-010470
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- smartcard_configure_cert_checking
- name: Replace 'none' from cert_policy
ansible.builtin.replace:
path: /etc/pam_pkcs11/pam_pkcs11.conf
regexp: (^\s*cert_policy\s*=\s*)none\s*;(\s*$)
replace: \g<1>ocsp_on,ca,signature;\g<2>
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture != "s390x"
- '''pam_pkcs11'' in ansible_facts.packages'
tags:
- CCE-83293-1
- DISA-STIG-SLES-15-010470
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- smartcard_configure_cert_checking
- name: Add 'ocsp_on' parameter for cert_policy in /etc/pam_pkcs11/pam_pkcs11.conf
ansible.builtin.replace:
path: /etc/pam_pkcs11/pam_pkcs11.conf
regexp: (^\s*cert_policy\s*=\s*)(?!.*ocsp_on)(.*)
replace: \g<1>ocsp_on,\g<2>
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture != "s390x"
- '''pam_pkcs11'' in ansible_facts.packages'
tags:
- CCE-83293-1
- DISA-STIG-SLES-15-010470
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- smartcard_configure_cert_checking
|
Enable Smart Card Logins in PAM
[ref]ruleThis requirement only applies to components where this is specific to the
function of the device or has the concept of an organizational user (e.g.,
VPN, proxy capability). This does not apply to authentication for the
purpose of configuring the device itself (management).
Check that the pam_pkcs11.so option is configured in the
etc/pam.d/common-auth file with the following command:
# grep pam_pkcs11.so /etc/pam.d/common-auth
auth sufficient pam_pkcs11.so
For general information about enabling smart card authentication, consult
the documentation at:
Rationale:Smart card login provides two-factor authentication stronger than
that provided by a username and password combination. Smart cards leverage PKI
(public key infrastructure) in order to provide and verify credentials.
Using an authentication device, such as a CAC or token that is separate
from the information system, ensures that even if the information system is
compromised, that compromise will not affect credentials stored on the
authentication device.
Multifactor solutions that require devices separate from information
systems gaining access include, for example, hardware tokens providing
time-based or challenge-response authenticators and smart cards
or similar secure authentication devices issued by an organization or identity provider. Identifiers:
CCE-85556-9 References:
SRG-OS-000068-GPOS-00036, SRG-OS-000105-GPOS-00052, SRG-OS-000106-GPOS-00053, SRG-OS-000107-GPOS-00054, SRG-OS-000108-GPOS-00055, SRG-OS-000375-GPOS-00160, SRG-OS-000375-GPOS-00161, SRG-OS-000375-GPOS-00162, SLES-15-020030, SLES-15-600600330, SV-234869r1009617_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/pam.d/common-auth" ] ; then
valueRegex="" defaultValue=""
# non-empty values need to be preceded by an equals sign
[ -n "${valueRegex}" ] && valueRegex="=${valueRegex}"
# add an equals sign to non-empty values
[ -n "${defaultValue}" ] && defaultValue="=${defaultValue}"
# fix 'type' if it's wrong
if grep -q -P "^\\s*(?"'!'"auth\\s)[[:alnum:]]+\\s+[[:alnum:]]+\\s+pam_pkcs11.so" < "/etc/pam.d/common-auth" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*)[[:alnum:]]+(\\s+[[:alnum:]]+\\s+pam_pkcs11.so)/\\1auth\\2/" "/etc/pam.d/common-auth"
fi
# fix 'control' if it's wrong
if grep -q -P "^\\s*auth\\s+(?"'!'"sufficient)[[:alnum:]]+\\s+pam_pkcs11.so" < "/etc/pam.d/common-auth" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*auth\\s+)[[:alnum:]]+(\\s+pam_pkcs11.so)/\\1sufficient\\2/" "/etc/pam.d/common-auth"
fi
# fix the value for 'option' if one exists but does not match 'valueRegex'
if grep -q -P "^\\s*auth\\s+sufficient\\s+pam_pkcs11.so(\\s.+)?\\s+(?"'!'"${valueRegex}(\\s|\$))" < "/etc/pam.d/common-auth" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*auth\\s+sufficient\\s+pam_pkcs11.so(\\s.+)?\\s)=[^[:space:]]*/\\1${defaultValue}/" "/etc/pam.d/common-auth"
# add 'option=default' if option is not set
elif grep -q -E "^\\s*auth\\s+sufficient\\s+pam_pkcs11.so" < "/etc/pam.d/common-auth" &&
grep -E "^\\s*auth\\s+sufficient\\s+pam_pkcs11.so" < "/etc/pam.d/common-auth" | grep -q -E -v "\\s(=|\\s|\$)" ; then
sed --follow-symlinks -i -E -e "s/^(\\s*auth\\s+sufficient\\s+pam_pkcs11.so[^\\n]*)/\\1 ${defaultValue}/" "/etc/pam.d/common-auth"
# add a new entry if none exists
elif ! grep -q -P "^\\s*auth\\s+sufficient\\s+pam_pkcs11.so(\\s.+)?\\s+${valueRegex}(\\s|\$)" < "/etc/pam.d/common-auth" ; then
echo "auth sufficient pam_pkcs11.so ${defaultValue}" >> "/etc/pam.d/common-auth"
fi
else
echo "/etc/pam.d/common-auth doesn't exist" >&2
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85556-9
- DISA-STIG-SLES-15-020030
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- smartcard_pam_enabled
- name: Enable Smart Card Logins in PAM - Gather List of Packages
ansible.builtin.package_facts:
manager: auto
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85556-9
- DISA-STIG-SLES-15-020030
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- smartcard_pam_enabled
- name: Enable Smart Card Logins in PAM - Check to See if 'pam_pkcs11' Module Is Configured
in '/etc/pam.d/common-auth'
ansible.builtin.shell: grep -E '^\s*auth\s+\S+\s+pam_pkcs11\.so' /etc/pam.d/common-auth
|| true
register: check_pam_pkcs11_module_result
changed_when: false
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam_pkcs11" in ansible_facts.packages'
tags:
- CCE-85556-9
- DISA-STIG-SLES-15-020030
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- smartcard_pam_enabled
- name: Enable Smart Card Logins in PAM - Configure 'pam_pkcs11' Module in '/etc/pam.d/common-auth'
ansible.builtin.lineinfile:
path: /etc/pam.d/common-auth
line: auth sufficient pam_pkcs11.so
insertafter: ^\s*#
state: present
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam_pkcs11" in ansible_facts.packages'
- '"pam_pkcs11.so" not in check_pam_pkcs11_module_result.stdout'
tags:
- CCE-85556-9
- DISA-STIG-SLES-15-020030
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- smartcard_pam_enabled
- name: Enable Smart Card Logins in PAM - Ensure 'pam_pkcs11' Module Has sufficient
Control Flag
ansible.builtin.lineinfile:
path: /etc/pam.d/common-auth
regexp: ^(\s*auth\s+)\S+(\s+pam_pkcs11\.so.*)
line: \g<1>sufficient\g<2>
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam_pkcs11" in ansible_facts.packages'
tags:
- CCE-85556-9
- DISA-STIG-SLES-15-020030
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- smartcard_pam_enabled
|
Protect Accounts by Restricting Password-Based Login
[ref]groupConventionally, Unix shell accounts are accessed by
providing a username and password to a login program, which tests
these values for correctness using the /etc/passwd and
/etc/shadow files. Password-based login is vulnerable to
guessing of weak passwords, and to sniffing and man-in-the-middle
attacks against passwords entered over a network or at an insecure
console. Therefore, mechanisms for accessing accounts by entering
usernames and passwords should be restricted to those which are
operationally necessary. |
| contains 32 rules |
Set Account Expiration Parameters
[ref]groupAccounts can be configured to be automatically disabled
after a certain time period,
meaning that they will require administrator interaction to become usable again.
Expiration of accounts after inactivity can be set for all accounts by default
and also on a per-account basis, such as for accounts that are known to be temporary.
To configure automatic expiration of an account following
the expiration of its password (that is, after the password has expired and not been changed),
run the following command, substituting NUM_DAYS and USER appropriately:
$ sudo chage -I NUM_DAYS USER
Accounts, such as temporary accounts, can also be configured to expire on an explicitly-set date with the
-E option.
The file /etc/default/useradd controls
default settings for all newly-created accounts created with the system's
normal command line utilities.Warning:
This will only apply to newly created accounts |
| contains 2 rules |
Set Account Expiration Following Inactivity
[ref]ruleTo specify the number of days after a password expires (which
signifies inactivity) until an account is permanently disabled, add or correct
the following line in /etc/default/useradd:
INACTIVE=30
If a password is currently on the verge of expiration, then
30
day(s) remain(s) until the account is automatically
disabled. However, if the password will not expire for another 60 days, then 60
days plus 30 day(s) could
elapse until the account would be automatically disabled. See the
useradd man page for more information.Rationale:Inactive identifiers pose a risk to systems and applications because attackers may exploit an inactive identifier and potentially obtain undetected access to the system.
Disabling inactive accounts ensures that accounts which may not have been responsibly removed are not available to attackers who may have compromised their credentials.
Owners of inactive accounts will not notice if unauthorized access to their user account has been obtained. Identifiers:
CCE-85558-5 References:
1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, 5.6.2.1.1, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.6, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, IA-4(e), AC-2(3), CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, Req-8.1.4, SRG-OS-000118-GPOS-00060, SLES-15-020050, 5.4.1.5, SLES-15-600600075, 8.2.6, 8.2, SV-234871r1009619_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q shadow; }; then
var_account_disable_post_pw_expiration='30'
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^INACTIVE")
# shellcheck disable=SC2059
printf -v formatted_output "%s=%s" "$stripped_key" "$var_account_disable_post_pw_expiration"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^INACTIVE\\>" "/etc/default/useradd"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^INACTIVE\\>.*/$escaped_formatted_output/gi" "/etc/default/useradd"
else
if [[ -s "/etc/default/useradd" ]] && [[ -n "$(tail -c 1 -- "/etc/default/useradd" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/default/useradd"
fi
cce="CCE-85558-5"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/default/useradd" >> "/etc/default/useradd"
printf '%s\n' "$formatted_output" >> "/etc/default/useradd"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85558-5
- CJIS-5.6.2.1.1
- DISA-STIG-SLES-15-020050
- NIST-800-171-3.5.6
- NIST-800-53-AC-2(3)
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-4(e)
- PCI-DSS-Req-8.1.4
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.6
- account_disable_post_pw_expiration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_account_disable_post_pw_expiration # promote to variable
set_fact:
var_account_disable_post_pw_expiration: !!str 30
tags:
- always
- name: Set Account Expiration Following Inactivity
ansible.builtin.lineinfile:
create: true
dest: /etc/default/useradd
regexp: ^INACTIVE
line: INACTIVE={{ var_account_disable_post_pw_expiration }}
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"shadow" in ansible_facts.packages'
tags:
- CCE-85558-5
- CJIS-5.6.2.1.1
- DISA-STIG-SLES-15-020050
- NIST-800-171-3.5.6
- NIST-800-53-AC-2(3)
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-4(e)
- PCI-DSS-Req-8.1.4
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.6
- account_disable_post_pw_expiration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure All Accounts on the System Have Unique Names
[ref]ruleEnsure accounts on the system have unique names.
To ensure all accounts have unique names, run the following command:
$ sudo getent passwd | awk -F: '{ print $1}' | uniq -d
If a username is returned, change or delete the username.Rationale:Unique usernames allow for accountability on the system. |
Set Password Expiration Parameters
[ref]groupThe file /etc/login.defs controls several
password-related settings. Programs such as passwd,
su, and
login consult /etc/login.defs to determine
behavior with regard to password aging, expiration warnings,
and length. See the man page login.defs(5) for more information.
Users should be forced to change their passwords, in order to
decrease the utility of compromised passwords. However, the need to
change passwords often should be balanced against the risk that
users will reuse or write down passwords if forced to change them
too often. Forcing password changes every 90-360 days, depending on
the environment, is recommended. Set the appropriate value as
PASS_MAX_DAYS and apply it to existing accounts with the
-M flag.
The PASS_MIN_DAYS (-m) setting prevents password
changes for 7 days after the first change, to discourage password
cycling. If you use this setting, train users to contact an administrator
for an emergency password change in case a new password becomes
compromised. The PASS_WARN_AGE (-W) setting gives
users 7 days of warnings at login time that their passwords are about to expire.
For example, for each existing human user USER, expiration parameters
could be adjusted to a 180 day maximum password age, 7 day minimum password
age, and 7 day warning period with the following command:
$ sudo chage -M 180 -m 7 -W 7 USER |
| contains 7 rules |
Set Password Maximum Age
[ref]ruleTo specify password maximum age for new accounts,
edit the file /etc/login.defs
and add or correct the following line:
PASS_MAX_DAYS 365
The profile requirement is 365.Rationale:Any password, no matter how complex, can eventually be cracked. Therefore, passwords
need to be changed periodically. If the operating system does not limit the lifetime
of passwords and force users to change their passwords, there is the risk that the
operating system passwords could be compromised.
Setting the password maximum age ensures users are required to
periodically change their passwords. Requiring shorter password lifetimes
increases the risk of users writing down the password in a convenient
location subject to physical compromise. Identifiers:
CCE-85570-0 References:
1, 12, 15, 16, 5, 5.6.2.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.6, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(f), IA-5(1)(d), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.4, SRG-OS-000076-GPOS-00044, SLES-15-020220, 5.4.1.2, SLES-15-600600015, 0418, 1055, 1402, 8.3.9, 8.3, SV-234891r1038967_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q shadow; }; then
var_accounts_maximum_age_login_defs='365'
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^PASS_MAX_DAYS")
# shellcheck disable=SC2059
printf -v formatted_output "%s %s" "$stripped_key" "$var_accounts_maximum_age_login_defs"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^PASS_MAX_DAYS\\>" "/etc/login.defs"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^PASS_MAX_DAYS\\>.*/$escaped_formatted_output/gi" "/etc/login.defs"
else
if [[ -s "/etc/login.defs" ]] && [[ -n "$(tail -c 1 -- "/etc/login.defs" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/login.defs"
fi
cce="CCE-85570-0"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/login.defs" >> "/etc/login.defs"
printf '%s\n' "$formatted_output" >> "/etc/login.defs"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85570-0
- CJIS-5.6.2.1
- DISA-STIG-SLES-15-020220
- NIST-800-171-3.5.6
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(d)
- NIST-800-53-IA-5(f)
- PCI-DSS-Req-8.2.4
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.9
- accounts_maximum_age_login_defs
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_accounts_maximum_age_login_defs # promote to variable
set_fact:
var_accounts_maximum_age_login_defs: !!str 365
tags:
- always
- name: Set Password Maximum Age
ansible.builtin.lineinfile:
create: true
dest: /etc/login.defs
regexp: ^#?PASS_MAX_DAYS
line: PASS_MAX_DAYS {{ var_accounts_maximum_age_login_defs }}
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"shadow" in ansible_facts.packages'
tags:
- CCE-85570-0
- CJIS-5.6.2.1
- DISA-STIG-SLES-15-020220
- NIST-800-171-3.5.6
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(d)
- NIST-800-53-IA-5(f)
- PCI-DSS-Req-8.2.4
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.9
- accounts_maximum_age_login_defs
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Set Password Minimum Age
[ref]ruleTo specify password minimum age for new accounts,
edit the file /etc/login.defs
and add or correct the following line:
PASS_MIN_DAYS 1
A value of 1 day is considered sufficient for many
environments.
The profile requirement is 1.Rationale:Enforcing a minimum password lifetime helps to prevent repeated password
changes to defeat the password reuse or history enforcement requirement. If
users are allowed to immediately and continually change their password,
then the password could be repeatedly changed in a short period of time to
defeat the organization's policy regarding password reuse.
Setting the minimum password age protects against users cycling back to a
favorite password after satisfying the password reuse requirement. Identifiers:
CCE-85720-1 References:
1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.8, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(1)(d), IA-5(1).1(v), PR.AC-1, PR.AC-6, PR.AC-7, SRG-OS-000075-GPOS-00043, SLES-15-020200, 5.4.1.3, SLES-15-600600030, 0418, 1055, 1402, SV-234889r1009628_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q shadow; }; then
var_accounts_minimum_age_login_defs='1'
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^PASS_MIN_DAYS")
# shellcheck disable=SC2059
printf -v formatted_output "%s %s" "$stripped_key" "$var_accounts_minimum_age_login_defs"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^PASS_MIN_DAYS\\>" "/etc/login.defs"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^PASS_MIN_DAYS\\>.*/$escaped_formatted_output/gi" "/etc/login.defs"
else
if [[ -s "/etc/login.defs" ]] && [[ -n "$(tail -c 1 -- "/etc/login.defs" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/login.defs"
fi
cce="CCE-85720-1"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/login.defs" >> "/etc/login.defs"
printf '%s\n' "$formatted_output" >> "/etc/login.defs"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85720-1
- CJIS-5.6.2.1.1
- DISA-STIG-SLES-15-020200
- NIST-800-171-3.5.8
- NIST-800-53-IA-5(1)(d)
- NIST-800-53-IA-5(1).1(v)
- accounts_minimum_age_login_defs
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_accounts_minimum_age_login_defs # promote to variable
set_fact:
var_accounts_minimum_age_login_defs: !!str 1
tags:
- always
- name: Set Password Minimum Age
ansible.builtin.lineinfile:
create: true
dest: /etc/login.defs
regexp: ^#?PASS_MIN_DAYS
line: PASS_MIN_DAYS {{ var_accounts_minimum_age_login_defs }}
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"shadow" in ansible_facts.packages'
tags:
- CCE-85720-1
- CJIS-5.6.2.1.1
- DISA-STIG-SLES-15-020200
- NIST-800-171-3.5.8
- NIST-800-53-IA-5(1)(d)
- NIST-800-53-IA-5(1).1(v)
- accounts_minimum_age_login_defs
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Set Existing Passwords Maximum Age
[ref]ruleConfigure non-compliant accounts to enforce a 365-day maximum password lifetime
restriction by running the following command:
$ sudo chage -M 365 USER Rationale:Any password, no matter how complex, can eventually be cracked. Therefore,
passwords need to be changed periodically. If the operating system does
not limit the lifetime of passwords and force users to change their
passwords, there is the risk that the operating system passwords could be
compromised. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_accounts_maximum_age_login_defs='365'
while IFS= read -r i; do
passwd -q -x $var_accounts_maximum_age_login_defs $i
done < <(awk -v var="$var_accounts_maximum_age_login_defs" -F: '(/^[^:]+:[^!*]/ && ($5 > var || $5 == "")) {print $1}' /etc/shadow)
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85571-8
- DISA-STIG-SLES-15-020230
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(d)
- NIST-800-53-IA-5(f)
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.9
- accounts_password_set_max_life_existing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_accounts_maximum_age_login_defs # promote to variable
set_fact:
var_accounts_maximum_age_login_defs: !!str 365
tags:
- always
- name: Collect users with not correct maximum time period between password changes
ansible.builtin.command:
cmd: awk -F':' '(/^[^:]+:[^!*]/ && ($5 > {{ var_accounts_maximum_age_login_defs
}} || $5 == "")) {print $1}' /etc/shadow
register: user_names
changed_when: false
check_mode: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85571-8
- DISA-STIG-SLES-15-020230
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(d)
- NIST-800-53-IA-5(f)
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.9
- accounts_password_set_max_life_existing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Change the maximum time period between password changes
ansible.builtin.command:
cmd: passwd -q -x {{ var_accounts_maximum_age_login_defs }} {{ item }}
with_items: '{{ user_names.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- user_names.stdout_lines | length > 0
tags:
- CCE-85571-8
- DISA-STIG-SLES-15-020230
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(d)
- NIST-800-53-IA-5(f)
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.9
- accounts_password_set_max_life_existing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Set Existing Passwords Minimum Age
[ref]ruleConfigure non-compliant accounts to enforce a 24 hours/1 day minimum password
lifetime by running the following command:
$ sudo chage -m 1 USER Rationale:Enforcing a minimum password lifetime helps to prevent repeated password
changes to defeat the password reuse or history enforcement requirement. If
users are allowed to immediately and continually change their password, the
password could be repeatedly changed in a short period of time to defeat the
organization's policy regarding password reuse. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_accounts_minimum_age_login_defs='1'
while IFS= read -r i; do
passwd -q -n $var_accounts_minimum_age_login_defs $i
done < <(awk -v var="$var_accounts_minimum_age_login_defs" -F: '(/^[^:]+:[^!*]/ && ($4 < var || $4 == "")) {print $1}' /etc/shadow)
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85710-2
- DISA-STIG-SLES-15-020210
- NIST-800-53-IA-5(1).1(v)
- accounts_password_set_min_life_existing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_accounts_minimum_age_login_defs # promote to variable
set_fact:
var_accounts_minimum_age_login_defs: !!str 1
tags:
- always
- name: Collect users with not correct minimum time period between password changes
ansible.builtin.command: |
awk -F':' '(/^[^:]+:[^!*]/ && ($4 < {{ var_accounts_minimum_age_login_defs }} || $4 == "")) {print $1}' /etc/shadow
register: user_names
changed_when: false
check_mode: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85710-2
- DISA-STIG-SLES-15-020210
- NIST-800-53-IA-5(1).1(v)
- accounts_password_set_min_life_existing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Change the minimum time period between password changes
ansible.builtin.command: |
passwd -q -n {{ var_accounts_minimum_age_login_defs }} {{ item }}
with_items: '{{ user_names.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- user_names.stdout_lines | length > 0
tags:
- CCE-85710-2
- DISA-STIG-SLES-15-020210
- NIST-800-53-IA-5(1).1(v)
- accounts_password_set_min_life_existing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Set Existing Passwords Warning Age
[ref]ruleTo configure how many days prior to password expiration that a warning will be issued to
users, run the command:
$ sudo chage --warndays 7 USER
This profile requirement is 7.Rationale:Providing an advance warning that a password will be expiring gives users
time to think of a secure password. Users caught unaware may choose a simple
password or write it down where it may be discovered. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_accounts_password_warn_age_login_defs='7'
while IFS= read -r i; do
chage --warndays $var_accounts_password_warn_age_login_defs $i
done < <(awk -v var="$var_accounts_password_warn_age_login_defs" -F: '(($6 < var || $6 == "") && $2 ~ /^\$/) {print $1}' /etc/shadow)
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92479-5
- NIST-800-53-IA-5(1).1(v)
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.9
- accounts_password_set_warn_age_existing
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: XCCDF Value var_accounts_password_warn_age_login_defs # promote to variable
set_fact:
var_accounts_password_warn_age_login_defs: !!str 7
tags:
- always
- name: Set Existing Passwords Warning Age - Collect Users With Incorrect Number of
Days of Warning Before Password Expires
ansible.builtin.command:
cmd: awk -F':' '(($6 < {{ var_accounts_password_warn_age_login_defs }} || $6 ==
"") && $2 ~ /^\$/) {print $1}' /etc/shadow
register: result_pass_warn_age_user_names
changed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92479-5
- NIST-800-53-IA-5(1).1(v)
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.9
- accounts_password_set_warn_age_existing
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set Existing Passwords Warning Age - Ensure the Number of Days of Warning
Before Password Expires
ansible.builtin.command:
cmd: chage --warndays {{ var_accounts_password_warn_age_login_defs }} {{ item
}}
with_items: '{{ result_pass_warn_age_user_names.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- result_pass_warn_age_user_names is not skipped and result_pass_warn_age_user_names.stdout_lines
| length > 0
tags:
- CCE-92479-5
- NIST-800-53-IA-5(1).1(v)
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.9
- accounts_password_set_warn_age_existing
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Set Password Warning Age
[ref]ruleTo specify how many days prior to password
expiration that a warning will be issued to users,
edit the file /etc/login.defs and add or correct
the following line:
PASS_WARN_AGE 7
The profile requirement is 7.Rationale:Setting the password warning age enables users to
make the change at a practical time. Identifiers:
CCE-91335-0 References:
1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.8, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, IA-5(f), IA-5(1)(d), CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, Req-8.2.4, 5.4.1.4, SLES-15-600600045, 0418, 1055, 1402, 8.3.9, 8.3 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q shadow; }; then
var_accounts_password_warn_age_login_defs='7'
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^PASS_WARN_AGE")
# shellcheck disable=SC2059
printf -v formatted_output "%s %s" "$stripped_key" "$var_accounts_password_warn_age_login_defs"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^PASS_WARN_AGE\\>" "/etc/login.defs"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^PASS_WARN_AGE\\>.*/$escaped_formatted_output/gi" "/etc/login.defs"
else
if [[ -s "/etc/login.defs" ]] && [[ -n "$(tail -c 1 -- "/etc/login.defs" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/login.defs"
fi
cce="CCE-91335-0"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/login.defs" >> "/etc/login.defs"
printf '%s\n' "$formatted_output" >> "/etc/login.defs"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91335-0
- NIST-800-171-3.5.8
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(d)
- NIST-800-53-IA-5(f)
- PCI-DSS-Req-8.2.4
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.9
- accounts_password_warn_age_login_defs
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_accounts_password_warn_age_login_defs # promote to variable
set_fact:
var_accounts_password_warn_age_login_defs: !!str 7
tags:
- always
- name: Set Password Warning Age
ansible.builtin.lineinfile:
dest: /etc/login.defs
regexp: ^PASS_WARN_AGE *[0-9]*
state: present
line: PASS_WARN_AGE {{ var_accounts_password_warn_age_login_defs }}
create: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"shadow" in ansible_facts.packages'
tags:
- CCE-91335-0
- NIST-800-171-3.5.8
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(d)
- NIST-800-53-IA-5(f)
- PCI-DSS-Req-8.2.4
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.9
- accounts_password_warn_age_login_defs
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Set existing passwords a period of inactivity before they been locked
[ref]ruleConfigure user accounts that have been inactive for over a given period of time
to be automatically disabled by running the following command:
$ sudo chage --inactive 30 USER Rationale:Inactive accounts pose a threat to system security since the users are not logging in to
notice failed login attempts or other anomalies. Identifiers:
CCE-92480-3 References:
DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.6, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, IA-4(e), AC-2(3), CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, Req-8.1.4, SRG-OS-000118-GPOS-00060, 5.4.1.5, SLES-15-600600075, 8.2.6, 8.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_account_disable_post_pw_expiration='30'
while IFS= read -r i; do
chage --inactive $var_account_disable_post_pw_expiration $i
done < <(awk -v var="$var_account_disable_post_pw_expiration" -F: '(($7 > var || $7 == "") && $2 ~ /^\$/) {print $1}' /etc/shadow)
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92480-3
- NIST-800-171-3.5.6
- NIST-800-53-AC-2(3)
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-4(e)
- PCI-DSS-Req-8.1.4
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.6
- accounts_set_post_pw_existing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_account_disable_post_pw_expiration # promote to variable
set_fact:
var_account_disable_post_pw_expiration: !!str 30
tags:
- always
- name: Collect users with not correct INACTIVE parameter set
ansible.builtin.command:
cmd: awk -F':' '(($7 > {{ var_account_disable_post_pw_expiration }} || $7 == "")
&& $2 ~ /^\$/) {print $1}' /etc/shadow
register: user_names
changed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92480-3
- NIST-800-171-3.5.6
- NIST-800-53-AC-2(3)
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-4(e)
- PCI-DSS-Req-8.1.4
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.6
- accounts_set_post_pw_existing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Change the period of inactivity
ansible.builtin.command:
cmd: chage --inactive {{ var_account_disable_post_pw_expiration }} {{ item }}
with_items: '{{ user_names.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- user_names is not skipped and user_names.stdout_lines | length > 0
tags:
- CCE-92480-3
- NIST-800-171-3.5.6
- NIST-800-53-AC-2(3)
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-4(e)
- PCI-DSS-Req-8.1.4
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.6
- accounts_set_post_pw_existing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Verify Proper Storage and Existence of Password
Hashes
[ref]groupBy default, password hashes for local accounts are stored
in the second field (colon-separated) in
/etc/shadow. This file should be readable only by
processes running with root credentials, preventing users from
casually accessing others' password hashes and attempting
to crack them.
However, it remains possible to misconfigure the system
and store password hashes
in world-readable files such as /etc/passwd, or
to even store passwords themselves in plaintext on the system.
Using system-provided tools for password change/creation
should allow administrators to avoid such misconfiguration. |
| contains 9 rules |
Verify All Account Password Hashes are Shadowed
[ref]ruleIf any password hashes are stored in /etc/passwd (in the second field,
instead of an x or *), the cause of this misconfiguration should be
investigated. The account should have its password reset and the hash should be
properly stored, or the account should be deleted entirely. Rationale:The hashes for all user account passwords should be stored in
the file /etc/shadow and never in /etc/passwd,
which is readable by all users. Identifiers:
CCE-85846-4 References:
1, 12, 15, 16, 5, 5.5.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.10, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(h), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, 6.2.1, SLES-15-900300015, 1402, 8.3.2, 8.3 |
Verify All Account Password Hashes are Shadowed with SHA512
[ref]ruleVerify the operating system requires the shadow password suite
configuration be set to encrypt interactive user passwords using a strong
cryptographic hash.
Check that the interactive user account passwords are using a strong
password hash with the following command:
$ sudo cut -d: -f2 /etc/shadow
$6$kcOnRq/5$NUEYPuyL.wghQwWssXRcLRFiiru7f5JPV6GaJhNC2aK5F3PZpE/BCCtwrxRc/AInKMNX3CdMw11m9STiql12f/
Password hashes ! or * indicate inactive accounts not
available for logon and are not evaluated.
If any interactive user password hash does not begin with $6,
this is a finding.Rationale:Passwords need to be protected at all times, and encryption is the standard method for
protecting passwords. If passwords are not encrypted, they can be plainly read
(i.e., clear text) and easily compromised. |
Ensure all users last password change date is in the past
[ref]ruleAll users should have a password change date in the past. Warning:
Automatic remediation is not available, in order to avoid any system disruption. Rationale:If a user recorded password change date is in the future then they could
bypass any set password expiration. |
All GIDs referenced in /etc/passwd must be defined in /etc/group
[ref]ruleAdd a group to the system for each GID referenced without a corresponding group. Rationale:If a user is assigned the Group Identifier (GID) of a group not existing on the system, and a group
with the Group Identifier (GID) is subsequently created, the user may have unintended rights to
any files associated with the group. Identifiers:
CCE-85847-2 References:
1, 12, 15, 16, 5, 5.5.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, IA-2, CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.5.a, SRG-OS-000104-GPOS-00051, 6.2.13, SLES-15-900300045, 8.2.2, 8.2 |
Prevent Login to Accounts With Empty Password
[ref]ruleIf an account is configured for password authentication
but does not have an assigned password, it may be possible to log
into the account without authentication. Remove any instances of the
nullok in
password authentication configurations in /etc/pam.d/
to prevent logins with empty passwords. Warning:
If the system relies on authselect tool to manage PAM settings, the remediation
will also use authselect tool. However, if any manual modification was made in
PAM files, the authselect integrity check will fail and the remediation will be
aborted in order to preserve intentional changes. In this case, an informative message will
be shown in the remediation report.
Note that this rule is not applicable for systems running within a
container. Having user with empty password within a container is not
considered a risk, because it should not be possible to directly login into
a container anyway. Rationale:If an account has an empty password, anyone could log in and
run commands with the privileges of that account. Accounts with
empty passwords should never be used in operational environments. Identifiers:
CCE-85576-7 References:
1, 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2, APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10, 3.1.1, 3.1.5, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, IA-5(1)(a), IA-5(c), CM-6(a), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, FIA_UAU.1, Req-8.2.3, SRG-OS-000480-GPOS-00227, SLES-15-020300, SLES-15-600450225, 1546, 8.3.1, 8.3, SV-234898r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
PAM_PATH="/etc/pam.d/"
NULLOK_FILES=$(grep -rl ".*pam_unix\\.so.*nullok.*" ${PAM_PATH})
for FILE in ${NULLOK_FILES}; do
sed --follow-symlinks -i 's/\<nullok\>//g' ${FILE}
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85576-7
- CJIS-5.5.2
- DISA-STIG-SLES-15-020300
- NIST-800-171-3.1.1
- NIST-800-171-3.1.5
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(c)
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.1
- configure_strategy
- high_severity
- low_complexity
- medium_disruption
- no_empty_passwords
- no_reboot_needed
- name: Find files in /etc/pam.d/ with password auth
ansible.builtin.find:
paths: /etc/pam.d
contains: .*pam_unix\.so.*nullok.*
recurse: true
register: find_pam_conf_files_result
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85576-7
- CJIS-5.5.2
- DISA-STIG-SLES-15-020300
- NIST-800-171-3.1.1
- NIST-800-171-3.1.5
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(c)
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.1
- configure_strategy
- high_severity
- low_complexity
- medium_disruption
- no_empty_passwords
- no_reboot_needed
- name: Prevent Log In to Accounts with Empty Password
ansible.builtin.replace:
dest: '{{ item.path }}'
regexp: nullok
with_items: '{{ find_pam_conf_files_result.files }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85576-7
- CJIS-5.5.2
- DISA-STIG-SLES-15-020300
- NIST-800-171-3.1.1
- NIST-800-171-3.1.5
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(a)
- NIST-800-53-IA-5(c)
- PCI-DSS-Req-8.2.3
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.1
- configure_strategy
- high_severity
- low_complexity
- medium_disruption
- no_empty_passwords
- no_reboot_needed
|
Verify No .forward Files Exist
[ref]ruleThe .forward file specifies an email address to forward the user's mail to. Rationale:Use of the .forward file poses a security risk in that sensitive data may
be inadvertently transferred outside the organization. The .forward file
also poses a risk as it can be used to execute commands that may perform
unintended actions. |
Ensure there are no legacy + NIS entries in /etc/passwd
[ref]ruleThe + character in /etc/passwd file marks a place where
entries from a network information service (NIS) should be directly inserted. Rationale:Using this method to include entries into /etc/passwd is considered legacy
and should be avoided. These entries may provide a way for an attacker
to gain access to the system. Remediation Shell script: (show)
if grep -q '^\+' /etc/passwd; then
# backup old file to /etc/passwd-
cp /etc/passwd /etc/passwd-
sed -i '/^\+.*$/d' /etc/passwd
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Ensure there are no legacy + NIS entries in /etc/passwd - Backup the Old /etc/passwd
File
ansible.builtin.copy:
src: /etc/passwd
dest: /etc/passwd-
remote_src: true
tags:
- CCE-91399-6
- low_complexity
- medium_disruption
- medium_severity
- no_legacy_plus_entries_etc_passwd
- no_reboot_needed
- restrict_strategy
- name: Ensure there are no legacy + NIS entries in /etc/passwd - Remove Lines Starting
with + From /etc/passwd
ansible.builtin.lineinfile:
regexp: ^\+.*$
state: absent
path: /etc/passwd
tags:
- CCE-91399-6
- low_complexity
- medium_disruption
- medium_severity
- no_legacy_plus_entries_etc_passwd
- no_reboot_needed
- restrict_strategy
|
Ensure there are no legacy + NIS entries in /etc/shadow
[ref]ruleThe + character in /etc/shadow file marks a place where
entries from a network information service (NIS) should be directly inserted. Rationale:Using this method to include entries into /etc/shadow is considered legacy
and should be avoided. These entries may provide a way for an attacker
to gain access to the system. Remediation Shell script: (show)
if grep -q '^\+' /etc/shadow; then
# backup old file to /etc/shadow-
cp /etc/shadow /etc/shadow-
sed -i '/^\+.*$/d' /etc/shadow
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Ensure there are no legacy + NIS entries in /etc/shadow - Backup the Old /etc/shadow
File
ansible.builtin.copy:
src: /etc/shadow
dest: /etc/shadow-
remote_src: true
tags:
- CCE-91402-8
- low_complexity
- medium_disruption
- medium_severity
- no_legacy_plus_entries_etc_shadow
- no_reboot_needed
- restrict_strategy
- name: Ensure there are no legacy + NIS entries in /etc/shadow - Remove Lines Starting
with + From /etc/shadow
ansible.builtin.lineinfile:
regexp: ^\+.*$
state: absent
path: /etc/shadow
tags:
- CCE-91402-8
- low_complexity
- medium_disruption
- medium_severity
- no_legacy_plus_entries_etc_shadow
- no_reboot_needed
- restrict_strategy
|
Verify No netrc Files Exist
[ref]ruleThe .netrc files contain login information
used to auto-login into FTP servers and reside in the user's home
directory. These files may contain unencrypted passwords to
remote FTP servers making them susceptible to access by unauthorized
users and should not be used. Any .netrc files should be removed. Rationale:Unencrypted passwords for remote FTP servers may be stored in .netrc
files. Identifiers:
CCE-92655-0 References:
1, 11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-003-8 R1.3, CIP-003-8 R3, CIP-003-8 R3.1, CIP-003-8 R3.2, CIP-003-8 R3.3, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, IA-5(h), IA-5(1)(c), CM-6(a), IA-5(7), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.PT-3, 6.2.10, SLEM-5-SMA-02100000, SLES-15-900300135 |
Restrict Root Logins
[ref]groupDirect root logins should be allowed only for emergency use.
In normal situations, the administrator should access the system
via a unique unprivileged account, and then use su or sudo to execute
privileged commands. Discouraging administrators from accessing the
root account directly ensures an audit trail in organizations with
multiple administrators. Locking down the channels through which
root can connect directly also reduces opportunities for
password-guessing against the root account. The login program
uses the file /etc/securetty to determine which interfaces
should allow root logins.
The virtual devices /dev/console
and /dev/tty* represent the system consoles (accessible via
the Ctrl-Alt-F1 through Ctrl-Alt-F6 keyboard sequences on a default
installation). The default securetty file also contains /dev/vc/*.
These are likely to be deprecated in most environments, but may be retained
for compatibility. Root should also be prohibited from connecting
via network protocols. Other sections of this document
include guidance describing how to prevent root from logging in via SSH. |
| contains 9 rules |
Verify Only Root Has UID 0
[ref]ruleIf any account other than root has a UID of 0, this misconfiguration should
be investigated and the accounts other than root should be removed or have
their UID changed.
If the account is associated with system commands or applications the UID
should be changed to one greater than "0" but less than "1000."
Otherwise assign a UID greater than "1000" that has not already been
assigned. Rationale:An account has root authority if it has a UID of 0. Multiple accounts
with a UID of 0 afford more opportunity for potential intruders to
guess a password for a privileged account. Proper configuration of
sudo is recommended to afford multiple system administrators
access to root privileges in an accountable manner. Identifiers:
CCE-85664-1 References:
1, 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10, 3.1.1, 3.1.5, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CM-6(b), CM-6.1(iv), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, Req-8.5, SRG-OS-000480-GPOS-00227, SLES-15-020100, 6.2.3, SLES-15-600600105, 1546, 8.2.1, 8.2, SV-234876r991589_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
awk -F: '$3 == 0 && $1 != "root" { print $1 }' /etc/passwd | xargs --no-run-if-empty --max-lines=1 passwd -l
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85664-1
- DISA-STIG-SLES-15-020100
- NIST-800-171-3.1.1
- NIST-800-171-3.1.5
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSS-Req-8.5
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.1
- accounts_no_uid_except_zero
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
- name: Get all /etc/passwd file entries
ansible.builtin.getent:
database: passwd
split: ':'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85664-1
- DISA-STIG-SLES-15-020100
- NIST-800-171-3.1.1
- NIST-800-171-3.1.5
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSS-Req-8.5
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.1
- accounts_no_uid_except_zero
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
- name: Lock the password of the user accounts other than root with uid 0
ansible.builtin.command: passwd -l {{ item.key }}
loop: '{{ getent_passwd | dict2items | rejectattr(''key'', ''search'', ''root'')
| list }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- item.value.1 == '0'
tags:
- CCE-85664-1
- DISA-STIG-SLES-15-020100
- NIST-800-171-3.1.1
- NIST-800-171-3.1.5
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSS-Req-8.5
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.1
- accounts_no_uid_except_zero
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
|
Verify Root Has A Primary GID 0
[ref]ruleThe root user should have a primary group of 0. Rationale:To help ensure that root-owned files are not inadvertently exposed to other users. |
Ensure the Group Used by pam_wheel.so Module Exists on System and is Empty
[ref]ruleEnsure that the group sugroup referenced by
var_pam_wheel_group_for_su variable and used as value for the pam_wheel.so
group option exists and has no members. This empty group used by
pam_wheel.so in /etc/pam.d/su ensures that no user can run commands with
altered privileges through the su command. Warning:
Note that this rule just ensures the group exists and has no members. This rule does not
configure pam_wheel.so module. The pam_wheel.so module configuration is
accomplished by use_pam_wheel_group_for_su rule. Rationale:The su program allows to run commands with a substitute user and group ID.
It is commonly used to run commands as the root user.
Limiting access to such command is considered a good security practice. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_pam_wheel_group_for_su='sugroup'
# Workaround for https://github.com/OpenSCAP/openscap/issues/2242: Use full
# path to groupadd command to avoid the issue with the command not being found.
if ! grep -q "^${var_pam_wheel_group_for_su}:[^:]*:[^:]*:[^:]*" /etc/group; then
/usr/sbin/groupadd ${var_pam_wheel_group_for_su}
fi
# group must be empty
gpasswd -M '' ${var_pam_wheel_group_for_su}
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92528-9
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- ensure_pam_wheel_group_empty
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_pam_wheel_group_for_su # promote to variable
set_fact:
var_pam_wheel_group_for_su: !!str sugroup
tags:
- always
- name: Ensure the Group Used by pam_wheel.so Module Exists on System and is Empty
- Ensure {{ var_pam_wheel_group_for_su }} Group Exists
ansible.builtin.group:
name: '{{ var_pam_wheel_group_for_su }}'
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92528-9
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- ensure_pam_wheel_group_empty
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure the Group Used by pam_wheel.so Module Exists on System and is Empty
- Ensure {{ var_pam_wheel_group_for_su }} Group is Empty
ansible.builtin.lineinfile:
path: /etc/group
regexp: ^({{ var_pam_wheel_group_for_su }}:[^:]+:[0-9]+:).*$
line: \1
backrefs: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92528-9
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- ensure_pam_wheel_group_empty
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure Authentication Required for Single User Mode
[ref]ruleSingle user mode is used for recovery when the system detects an
issue during boot or by manual selection from the bootloader. Rationale:Requiring authentication in single user mode prevents an unauthorized
user from rebooting the system into single user to gain root privileges
without credentials. |
Verify Only Group Root Has GID 0
[ref]ruleIf any group other than root has a GID of 0, this misconfiguration should
be investigated and the groups other than root should be removed or have
their GID changed. Warning:
This rule doesn't come with a remediation. The removal of groups from a system
or reassigning the GID is considered too disruptive. Rationale:Ensuring that only the root group has a GID of 0 helps prevent
root group owned files from becoming accidentally accessible to
non-privileged users. |
Verify Non-Interactive Accounts Are Locked
[ref]ruleAccounts meant for non-interactive purposes should be locked to prevent
unauthorized access. Accounts with non-standard shells (those not defined in
/etc/shells) should be locked using usermod -L. Warning:
Automatic remediation of this control is not recommended. Locking system accounts
could be highly disruptive. Rationale:Locking non-interactive accounts improves security by preventing potential
misuse. While many systems configure these accounts with invalid strings,
setting the shell field to nologin is also suggested |
Ensure that System Accounts Are Locked
[ref]ruleSome accounts are not associated with a human user of the system, and exist to perform some
administrative functions. An attacker should not be able to log into these accounts.
System accounts are those user accounts with a user ID less than 1000.
If any system account other than root, halt, sync, shutdown
and nfsnobody has an unlocked password, disable it with the command:
$ sudo usermod -L account Rationale:Disabling authentication for default system accounts makes it more difficult for attackers
to make use of them to compromise a system. Identifiers:
CCE-92593-3 References:
CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-6, CM-6(a), SLES-15-600600195, 8.2.2, 8.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
readarray -t systemaccounts < <(awk -F: \
'($3 < 1000 && $3 != root && $3 != halt && $3 != sync && $3 != shutdown \
&& $3 != nfsnobody) { print $1 }' /etc/passwd)
for systemaccount in "${systemaccounts[@]}"; do
usermod -L "$systemaccount"
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92593-3
- NIST-800-53-AC-6
- NIST-800-53-CM-6(a)
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.2
- low_complexity
- medium_disruption
- medium_severity
- no_password_auth_for_systemaccounts
- no_reboot_needed
- restrict_strategy
- name: Ensure that System Accounts Are Locked - Get All Local Users From /etc/passwd
ansible.builtin.getent:
database: passwd
split: ':'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92593-3
- NIST-800-53-AC-6
- NIST-800-53-CM-6(a)
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.2
- low_complexity
- medium_disruption
- medium_severity
- no_password_auth_for_systemaccounts
- no_reboot_needed
- restrict_strategy
- name: Ensure that System Accounts Are Locked - Create local_users Variable From
getent_passwd Facts
ansible.builtin.set_fact:
local_users: '{{ ansible_facts.getent_passwd | dict2items }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92593-3
- NIST-800-53-AC-6
- NIST-800-53-CM-6(a)
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.2
- low_complexity
- medium_disruption
- medium_severity
- no_password_auth_for_systemaccounts
- no_reboot_needed
- restrict_strategy
- name: Ensure that System Accounts Are Locked - Lock System Accounts
ansible.builtin.user:
name: '{{ item.key }}'
password_lock: true
loop: '{{ local_users }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- item.value[1]|int < 1000
- item.key not in ['root', 'halt', 'sync', 'shutdown', 'nfsnobody']
tags:
- CCE-92593-3
- NIST-800-53-AC-6
- NIST-800-53-CM-6(a)
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.2
- low_complexity
- medium_disruption
- medium_severity
- no_password_auth_for_systemaccounts
- no_reboot_needed
- restrict_strategy
|
Ensure that System Accounts Do Not Run a Shell Upon Login
[ref]ruleSome accounts are not associated with a human user of the system, and exist to perform some
administrative functions. Should an attacker be able to log into these accounts, they should
not be granted access to a shell.
The login shell for each local account is stored in the last field of each line in
/etc/passwd. System accounts are those user accounts with a user ID less than
1000. The user ID is stored in the third field. If any system account
other than root has a login shell, disable it with the command:
$ sudo usermod -s /sbin/nologin account Warning:
Do not perform the steps in this section on the root account. Doing so might cause the
system to become inaccessible. Rationale:Ensuring shells are not given to system accounts upon login makes it more difficult for
attackers to make use of system accounts. Identifiers:
CCE-85672-4 References:
1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS06.03, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, AC-6, CM-6(a), CM-6(b), CM-6.1(iv), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, SRG-OS-000480-GPOS-00227, SLES-15-020091, 5.4.2, SLES-15-600600195, 1491, 8.2.2, 8.2, SV-234875r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
readarray -t systemaccounts < <(awk -F: '($3 < 1000 && $3 != root \
&& $7 != "\/sbin\/shutdown" && $7 != "\/sbin\/halt" && $7 != "\/bin\/sync") \
{ print $1 }' /etc/passwd)
for systemaccount in "${systemaccounts[@]}"; do
usermod -s /sbin/nologin "$systemaccount"
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85672-4
- DISA-STIG-SLES-15-020091
- NIST-800-53-AC-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.2
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- no_shelllogin_for_systemaccounts
- restrict_strategy
- name: Ensure that System Accounts Do Not Run a Shell Upon Login - Get All Local
Users From /etc/passwd
ansible.builtin.getent:
database: passwd
split: ':'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85672-4
- DISA-STIG-SLES-15-020091
- NIST-800-53-AC-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.2
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- no_shelllogin_for_systemaccounts
- restrict_strategy
- name: Ensure that System Accounts Do Not Run a Shell Upon Login - Create local_users
Variable From getent_passwd Facts
ansible.builtin.set_fact:
local_users: '{{ ansible_facts.getent_passwd | dict2items }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85672-4
- DISA-STIG-SLES-15-020091
- NIST-800-53-AC-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.2
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- no_shelllogin_for_systemaccounts
- restrict_strategy
- name: Ensure that System Accounts Do Not Run a Shell Upon Login - Disable Login
Shell for System Accounts
ansible.builtin.user:
name: '{{ item.key }}'
shell: /sbin/nologin
loop: '{{ local_users }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- item.key not in ['root']
- item.value[1]|int < 1000
- item.value[5] not in ['/sbin/shutdown', '/sbin/halt', '/bin/sync']
tags:
- CCE-85672-4
- DISA-STIG-SLES-15-020091
- NIST-800-53-AC-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.2
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- no_shelllogin_for_systemaccounts
- restrict_strategy
|
Enforce Usage of pam_wheel with Group Parameter for su Authentication
[ref]ruleTo ensure that only users who are members of the group set in the group option of
pam_wheel.so module can run commands with altered privileges through the su
command, make sure that the following line exists in the file /etc/pam.d/su:
auth required pam_wheel.so use_uid group=sugroup Warning:
Note that ensure_pam_wheel_group_empty rule complements this requirement by
ensuring the referenced group exists and has no members. Rationale:The su program allows to run commands with a substitute user and group ID.
It is commonly used to run commands as the root user.
Limiting access to such command is considered a good security practice. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then
var_pam_wheel_group_for_su='sugroup'
PAM_CONF=/etc/pam.d/su
pamstr=$(grep -P '^auth\s+required\s+pam_wheel\.so\s+(?=[^#]*\buse_uid\b)(?=[^#]*\bgroup=)' ${PAM_CONF})
if [ -z "$pamstr" ]; then
sed -Ei '/^auth\b.*\brequired\b.*\bpam_wheel\.so/d' ${PAM_CONF} # remove any remaining uncommented pam_wheel.so line
sed -Ei "/^auth\s+sufficient\s+pam_rootok\.so.*$/a auth required pam_wheel.so use_uid group=${var_pam_wheel_group_for_su}" ${PAM_CONF}
else
group_val=$(echo -n "$pamstr" | grep -Eo '\bgroup=[_a-z][-0-9_a-z]*' | cut -d '=' -f 2)
if [ -z "${group_val}" ] || [ ${group_val} != ${var_pam_wheel_group_for_su} ]; then
sed -Ei "s/(^auth\s+required\s+pam_wheel.so\s+[^#]*group=)[_a-z][-0-9_a-z]*/\1${var_pam_wheel_group_for_su}/" ${PAM_CONF}
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92522-2
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- use_pam_wheel_group_for_su
- name: XCCDF Value var_pam_wheel_group_for_su # promote to variable
set_fact:
var_pam_wheel_group_for_su: !!str sugroup
tags:
- always
- name: Enforce Usage of pam_wheel with Group Parameter for su Authentication - Add
the group to the /etc/pam.d/su file
ansible.builtin.lineinfile:
path: /etc/pam.d/su
state: present
regexp: ^[\s]*#[\s]*auth[\s]+required[\s]+pam_wheel\.so[\s]+use_uid group=$
line: auth required pam_wheel.so use_uid group={{ var_pam_wheel_group_for_su
}}
when: '"pam" in ansible_facts.packages'
tags:
- CCE-92522-2
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- use_pam_wheel_group_for_su
|
Ensure All Accounts on the System Have Unique User IDs
[ref]ruleChange user IDs (UIDs), or delete accounts, so each has a unique name. Warning:
Automatic remediation of this control is not available due to unique requirements of each
system. Rationale:To assure accountability and prevent unauthenticated access, interactive users must be identified and authenticated to prevent potential misuse and compromise of the system. |
Only Authorized Local User Accounts Exist on Operating System
[ref]ruleEnterprise Application tends to use the server or virtual machine exclusively.
Besides the default operating system user, there should be only authorized local
users required by the installed software groups and applications that exist on
the operating system. The authorized user list can be customized in the refine
value variable var_accounts_authorized_local_users_regex.
OVAL regular expression is used for the user list.
Configure the system so all accounts on the system are assigned to an active system,
application, or user account. Remove accounts that do not support approved system
activities or that allow for a normal user to perform administrative-level actions.
To remove unauthorized system accounts, use the following command:
$ sudo userdel unauthorized_user Rationale:Accounts providing no operational purpose provide additional opportunities for
system compromise. Unnecessary accounts include user accounts for individuals not
requiring access to the system and application accounts for applications not installed
on the system. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_accounts_authorized_local_users_regex='^(root|bin|daemon|adm|lp|sync|shutdown|halt|mail|operator|games|ftp|nobody|pegasus|systemd-bus-proxy|systemd-network|dbus|polkitd|abrt|unbound|tss|libstoragemgmt|rpc|colord|usbmuxd$|pcp|saslauth|geoclue|setroubleshoot|rtkit|chrony|qemu|radvd|rpcuser|nfsnobody|pulse|gdm|gnome-initial-setup|postfix|avahi|ntp|sshd|tcpdump|oprofile|uuidd|systemd-resolve|systemd-coredump|sssd|rngd|man|systemd-timesync|scard|hacluster|statd|at|dockremap|vnc|messagebus|nscd|flatpak|srvGeoClue|tftp|wsdd|dnsmasq|usbmux|brltty)$'
# never delete the root user
default_os_user="root"
# delete users that is in /etc/passwd but neither in default_os_user
# nor in var_accounts_authorized_local_users_regex
for username in $( sed 's/:.*//' /etc/passwd ) ; do
if [[ ! "$username" =~ ($default_os_user|$var_accounts_authorized_local_users_regex) ]];
then
userdel $username ;
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85561-9
- DISA-STIG-SLES-15-020090
- accounts_authorized_local_users
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_accounts_authorized_local_users_regex # promote to variable
set_fact:
var_accounts_authorized_local_users_regex: !!str ^(root|bin|daemon|adm|lp|sync|shutdown|halt|mail|operator|games|ftp|nobody|pegasus|systemd-bus-proxy|systemd-network|dbus|polkitd|abrt|unbound|tss|libstoragemgmt|rpc|colord|usbmuxd$|pcp|saslauth|geoclue|setroubleshoot|rtkit|chrony|qemu|radvd|rpcuser|nfsnobody|pulse|gdm|gnome-initial-setup|postfix|avahi|ntp|sshd|tcpdump|oprofile|uuidd|systemd-resolve|systemd-coredump|sssd|rngd|man|systemd-timesync|scard|hacluster|statd|at|dockremap|vnc|messagebus|nscd|flatpak|srvGeoClue|tftp|wsdd|dnsmasq|usbmux|brltty)$
tags:
- always
- name: Read /etc/passwd
ansible.builtin.getent:
database: passwd
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85561-9
- DISA-STIG-SLES-15-020090
- accounts_authorized_local_users
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Remove unauthorized accounts
ansible.builtin.user:
name: '{{ item.key }}'
force: true
state: absent
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- item.key is not regex(var_accounts_authorized_local_users_regex)
with_dict: '{{ getent_passwd }}'
tags:
- CCE-85561-9
- DISA-STIG-SLES-15-020090
- accounts_authorized_local_users
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure All Groups on the System Have Unique Group ID
[ref]ruleChange the group name or delete groups, so each has a unique id. Warning:
Automatic remediation of this control is not available due to the unique requirements of each system. Rationale:To assure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system. |
Ensure All Groups on the System Have Unique Group Names
[ref]ruleChange the group name or delete groups, so each has a unique name. Warning:
Automatic remediation of this control is not available due to the unique requirements of each system. Rationale:To assure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system. |
Ensure nologin Shell is Not Listed in /etc/shells
[ref]ruleThe /sbin/nologin shell is used to restrict accounts from having login access
and should not be listed as a valid login shell in /etc/shells.
To verify that nologin is not listed in /etc/shells, run:
$ grep nologin /etc/shells
The command should return no output.Rationale:The /etc/shells is consulted by various programs to evaluate
whether the user is somehow restricted. For example, the chsh utility will
consult the file to determine if the user is allowed to change their shell. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
if grep -q -E "^[^#]*/nologin\b.*$" /etc/shells; then
sed -i --follow-symlinks 's/^[^#]*\/nologin\b.*$/#&/g' /etc/shells
fi
|
Secure Session Configuration Files for Login Accounts
[ref]groupWhen a user logs into a Unix account, the system
configures the user's session by reading a number of files. Many of
these files are located in the user's home directory, and may have
weak permissions as a result of user error or misconfiguration. If
an attacker can modify or even read certain types of account
configuration information, they can often gain full access to the
affected user's account. Therefore, it is important to test and
correct configuration file permissions for interactive accounts,
particularly those of privileged users such as root or system
administrators. |
| contains 18 rules |
Ensure that No Dangerous Directories Exist in Root's Path
[ref]groupThe active path of the root account can be obtained by
starting a new root shell and running:
# echo $PATH
This will produce a colon-separated list of
directories in the path.
Certain path elements could be considered dangerous, as they could lead
to root executing unknown or
untrusted programs, which could contain malicious
code.
Since root may sometimes work inside
untrusted directories, the . character, which represents the
current directory, should never be in the root path, nor should any
directory which can be written to by an unprivileged or
semi-privileged (system) user.
It is a good practice for administrators to always execute
privileged commands by typing the full path to the
command. |
| contains 2 rules |
Ensure that Root's Path Does Not Include World or Group-Writable Directories
[ref]ruleFor each element in root's path, run:
# ls -ld DIR
and ensure that write permissions are disabled for group and
other.Rationale:Such entries increase the risk that root could
execute code provided by unprivileged users,
and potentially malicious code. Identifiers:
CCE-91401-0 References:
11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, CM-6(a), CM-6(a), PR.IP-1, 6.2.4, SLES-15-600600165 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Get root paths which are not symbolic links
ansible.builtin.stat:
path: '{{ item }}'
changed_when: false
failed_when: false
register: root_paths
with_items: '{{ ansible_env.PATH.split('':'') }}'
tags:
- CCE-91401-0
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(a)
- accounts_root_path_dirs_no_write
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable writability to root directories
ansible.builtin.file:
path: '{{ item.item }}'
mode: g-w,o-w
with_items: '{{ root_paths.results }}'
when:
- root_paths.results is defined
- item.stat.exists
- not item.stat.islnk
tags:
- CCE-91401-0
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(a)
- accounts_root_path_dirs_no_write
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure that Root's Path Does Not Include Relative Paths or Null Directories
[ref]ruleEnsure that none of the directories in root's path is equal to a single
. character, or
that it contains any instances that lead to relative path traversal, such as
.. or beginning a path without the slash (/) character.
Also ensure that there are no "empty" elements in the path, such as in these examples:
PATH=:/bin
PATH=/bin:
PATH=/bin::/sbin
These empty elements have the same effect as a single . character.Rationale:Including these entries increases the risk that root could
execute code from an untrusted location. Identifiers:
CCE-91400-2 References:
11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, CM-6(a), CM-6(a), PR.IP-1, 6.2.4, SLES-15-600600165 |
Ensure that Users Have Sensible Umask Values
[ref]groupThe umask setting controls the default permissions
for the creation of new files.
With a default umask setting of 077, files and directories
created by users will not be readable by any other user on the
system. Users who wish to make specific files group- or
world-readable can accomplish this by using the chmod command.
Additionally, users can make all their files readable to their
group by default by setting a umask of 027 in their shell
configuration files. If default per-user groups exist (that is, if
every user has a default group whose name is the same as that
user's username and whose only member is the user), then it may
even be safe for users to select a umask of 007, making it very
easy to intentionally share files with groups of which the user is
a member.
|
| contains 4 rules |
Ensure the Default Bash Umask is Set Correctly
[ref]ruleTo ensure the default umask for users of the Bash shell is set properly,
add or correct the umask setting in /etc/bash.bashrc to read
as follows:
umask 027 Rationale:The umask value influences the permissions assigned to files when they are created.
A misconfigured umask value could result in files with excessive permissions that can be read or
written to by unauthorized users. Identifiers:
CCE-91215-4 References:
18, APO13.01, BAI03.01, BAI03.02, BAI03.03, 4.3.4.3.3, A.14.1.1, A.14.2.1, A.14.2.5, A.6.1.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-6(1), CM-6(a), PR.IP-2, SRG-OS-000480-GPOS-00228, SRG-OS-000480-GPOS-00227, 5.4.5, R36, SLES-15-600600255 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q bash; }; then
var_accounts_user_umask='027'
grep -q "^[^#]*\bumask" /etc/bash.bashrc && \
sed -i -E -e "s/^([^#]*\bumask)[[:space:]]+[[:digit:]]+/\1 $var_accounts_user_umask/g" /etc/bash.bashrc
if ! [ $? -eq 0 ]; then
echo "umask $var_accounts_user_umask" >> /etc/bash.bashrc
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91215-4
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- accounts_umask_etc_bashrc
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_accounts_user_umask # promote to variable
set_fact:
var_accounts_user_umask: !!str 027
tags:
- always
- name: Check if umask in /etc/bash.bashrc is already set
ansible.builtin.lineinfile:
path: /etc/bash.bashrc
regexp: ^[^#]*\bumask\s+\d+$
state: absent
check_mode: true
changed_when: false
register: umask_replace
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"bash" in ansible_facts.packages'
tags:
- CCE-91215-4
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- accounts_umask_etc_bashrc
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Replace user umask in /etc/bash.bashrc
ansible.builtin.replace:
path: /etc/bash.bashrc
regexp: ^([^#]*\b)umask\s+\d+$
replace: \g<1>umask {{ var_accounts_user_umask }}
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"bash" in ansible_facts.packages'
- umask_replace.found > 0
tags:
- CCE-91215-4
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- accounts_umask_etc_bashrc
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure the Default umask is Appended Correctly
ansible.builtin.lineinfile:
create: true
path: /etc/bash.bashrc
line: umask {{ var_accounts_user_umask }}
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"bash" in ansible_facts.packages'
- umask_replace.found == 0
tags:
- CCE-91215-4
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- accounts_umask_etc_bashrc
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure the Default Umask is Set Correctly in login.defs
[ref]ruleTo ensure the default umask controlled by /etc/login.defs is set properly,
add or correct the UMASK setting in /etc/login.defs to read as follows:
UMASK 027 Rationale:The umask value influences the permissions assigned to files when they are created.
A misconfigured umask value could result in files with excessive permissions that can be read and
written to by unauthorized users. Identifiers:
CCE-85659-1 References:
11, 18, 3, 9, APO13.01, BAI03.01, BAI03.02, BAI03.03, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.1.1, A.14.2.1, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.5, A.6.1.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-6(1), CM-6(a), PR.IP-1, PR.IP-2, SRG-OS-000480-GPOS-00228, SLES-15-040420, 5.4.5, R36, SLES-15-600600255, SV-235030r991590_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q shadow; }; then
var_accounts_user_umask='027'
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^UMASK")
# shellcheck disable=SC2059
printf -v formatted_output "%s %s" "$stripped_key" "$var_accounts_user_umask"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^UMASK\\>" "/etc/login.defs"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^UMASK\\>.*/$escaped_formatted_output/gi" "/etc/login.defs"
else
if [[ -s "/etc/login.defs" ]] && [[ -n "$(tail -c 1 -- "/etc/login.defs" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/login.defs"
fi
cce="CCE-85659-1"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/login.defs" >> "/etc/login.defs"
printf '%s\n' "$formatted_output" >> "/etc/login.defs"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85659-1
- DISA-STIG-SLES-15-040420
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- accounts_umask_etc_login_defs
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_accounts_user_umask # promote to variable
set_fact:
var_accounts_user_umask: !!str 027
tags:
- always
- name: Check if UMASK is already set
ansible.builtin.lineinfile:
path: /etc/login.defs
regexp: ^(\s*)UMASK\s+.*
state: absent
check_mode: true
changed_when: false
register: result_umask_is_set
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"shadow" in ansible_facts.packages'
tags:
- CCE-85659-1
- DISA-STIG-SLES-15-040420
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- accounts_umask_etc_login_defs
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Replace user UMASK in /etc/login.defs
ansible.builtin.replace:
path: /etc/login.defs
regexp: ^(\s*)UMASK(\s+).*
replace: \g<1>UMASK\g<2>{{ var_accounts_user_umask }}
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"shadow" in ansible_facts.packages'
- result_umask_is_set.found > 0
tags:
- CCE-85659-1
- DISA-STIG-SLES-15-040420
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- accounts_umask_etc_login_defs
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure the Default UMASK is Appended Correctly
ansible.builtin.lineinfile:
create: true
path: /etc/login.defs
line: UMASK {{ var_accounts_user_umask }}
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"shadow" in ansible_facts.packages'
- result_umask_is_set.found == 0
tags:
- CCE-85659-1
- DISA-STIG-SLES-15-040420
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- accounts_umask_etc_login_defs
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure the Default Umask is Set Correctly in /etc/profile
[ref]ruleTo ensure the default umask controlled by /etc/profile is set properly,
add or correct the umask setting in /etc/profile to read as follows:
umask 027
Note that /etc/profile also reads scripts within /etc/profile.d directory.
These scripts are also valid files to set umask value. Therefore, they should also be
considered during the check and properly remediated, if necessary.Rationale:The umask value influences the permissions assigned to files when they are created.
A misconfigured umask value could result in files with excessive permissions that can be read or
written to by unauthorized users. Identifiers:
CCE-91216-2 References:
18, APO13.01, BAI03.01, BAI03.02, BAI03.03, 4.3.4.3.3, A.14.1.1, A.14.2.1, A.14.2.5, A.6.1.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-6(1), CM-6(a), PR.IP-2, SRG-OS-000480-GPOS-00228, SRG-OS-000480-GPOS-00227, 5.4.5, R36, SLES-15-600600255 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_accounts_user_umask='027'
readarray -t profile_files < <(find /etc/profile.d/ -type f -name '*.sh' -or -name 'sh.local')
for file in "${profile_files[@]}" /etc/profile; do
grep -qE '^[^#]*umask' "$file" && sed -i -E "s/^(\s*umask\s*)[0-7]+/\1$var_accounts_user_umask/g" "$file"
done
if ! grep -qrE '^[^#]*umask' /etc/profile*; then
echo "umask $var_accounts_user_umask" >> /etc/profile
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91216-2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- accounts_umask_etc_profile
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_accounts_user_umask # promote to variable
set_fact:
var_accounts_user_umask: !!str 027
tags:
- always
- name: Ensure the Default Umask is Set Correctly in /etc/profile - Locate Profile
Configuration Files Where umask Is Defined
ansible.builtin.find:
paths:
- /etc/profile.d
patterns:
- sh.local
- '*.sh'
contains: ^[\s]*umask\s+\d+
register: result_profile_d_files
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91216-2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- accounts_umask_etc_profile
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure the Default Umask is Set Correctly in /etc/profile - Replace Existing
umask Value in Files From /etc/profile.d
ansible.builtin.replace:
path: '{{ item.path }}'
regexp: ^(\s*)umask\s+\d+
replace: \1umask {{ var_accounts_user_umask }}
loop: '{{ result_profile_d_files.files }}'
register: result_umask_replaced_profile_d
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- result_profile_d_files.matched
tags:
- CCE-91216-2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- accounts_umask_etc_profile
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure the Default Umask is Set Correctly in /etc/profile - Ensure umask Is
Set in /etc/profile if Not Already Set Elsewhere
ansible.builtin.lineinfile:
create: true
mode: 420
path: /etc/profile
line: umask {{ var_accounts_user_umask }}
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not result_profile_d_files.matched
tags:
- CCE-91216-2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- accounts_umask_etc_profile
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure the Default Umask is Set Correctly in /etc/profile - Ensure umask Value
For All Existing umask Definition in /etc/profile
ansible.builtin.replace:
path: /etc/profile
regexp: ^(\s*)umask\s+\d+
replace: \1umask {{ var_accounts_user_umask }}
register: result_umask_replaced_profile
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91216-2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- accounts_umask_etc_profile
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure the Root Bash Umask is Set Correctly
[ref]ruleTo ensure the root user's umask of the Bash shell is set properly,
add or correct the umask setting in /root/.bashrc
or /root/.profile to read as follows:
umask 0027 Rationale:The umask value influences the permissions assigned to files when they are created.
A misconfigured umask value could result in files with excessive permissions that can be read or
written to by unauthorized users. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q bash; }; then
for file in /root/.bashrc /root/.profile; do
if [ -f "$file" ]; then
sed -i -E -e "s/^([^#]*\bumask)[[:space:]]+[[:digit:]]+/\1 0027/g" "$file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Ensure Home Directories are Created for New Users
[ref]ruleAll local interactive user accounts, upon creation, should be assigned a home directory.
Configure the operating system to assign home directories to all new local interactive users by setting the CREATE_HOME
parameter in /etc/login.defs to yes as follows:
CREATE_HOME yes Rationale:If local interactive users are not assigned a valid home directory, there is no place
for the storage and control of files they should own. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( rpm --quiet -q shadow && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base ); then
if [ -e "/etc/login.defs" ] ; then
LC_ALL=C sed -i "/^\s*CREATE_HOME\s\+/Id" "/etc/login.defs"
else
touch "/etc/login.defs"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/login.defs"
cp "/etc/login.defs" "/etc/login.defs.bak"
# Insert before the line matching the regex '^\s*CREATE_HOME'.
line_number="$(LC_ALL=C grep -n "^\s*CREATE_HOME" "/etc/login.defs.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
# There was no match of '^\s*CREATE_HOME', insert at
# the end of the file.
printf '%s\n' "CREATE_HOME yes" >> "/etc/login.defs"
else
head -n "$(( line_number - 1 ))" "/etc/login.defs.bak" > "/etc/login.defs"
printf '%s\n' "CREATE_HOME yes" >> "/etc/login.defs"
tail -n "+$(( line_number ))" "/etc/login.defs.bak" >> "/etc/login.defs"
fi
# Clean up after ourselves.
rm "/etc/login.defs.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85562-7
- DISA-STIG-SLES-15-020110
- accounts_have_homedir_login_defs
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure new users receive home directories
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/login.defs
create: true
regexp: (?i)^\s*CREATE_HOME\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/login.defs
ansible.builtin.lineinfile:
path: /etc/login.defs
create: true
regexp: (?i)^\s*CREATE_HOME\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/login.defs
ansible.builtin.lineinfile:
path: /etc/login.defs
create: true
regexp: (?i)^\s*CREATE_HOME\s+
line: CREATE_HOME yes
state: present
when: ( "shadow" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
tags:
- CCE-85562-7
- DISA-STIG-SLES-15-020110
- accounts_have_homedir_login_defs
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Limit the Number of Concurrent Login Sessions Allowed Per User
[ref]ruleLimiting the number of allowed users and sessions per user can limit risks related to Denial of
Service attacks. This addresses concurrent sessions for a single account and does not address
concurrent sessions by a single user via multiple accounts. To set the number of concurrent
sessions per user add the following line in /etc/security/limits.conf or
a file under /etc/security/limits.d/:
* hard maxlogins 1 Rationale:Limiting simultaneous user logins can insulate the system from denial of service
problems caused by excessive logins. Automated login processes operating improperly or
maliciously may result in an exceptional number of simultaneous login sessions. Identifiers:
CCE-85555-1 References:
14, 15, 18, 9, 5.5.2.2, DSS01.05, DSS05.02, 4.3.3.4, SR 3.1, SR 3.8, A.13.1.1, A.13.1.3, A.13.2.1, A.14.1.2, A.14.1.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, AC-10, CM-6(a), PR.AC-5, SRG-OS-000027-GPOS-00008, SLES-15-020020, SLES-15-600600285, SV-234868r958398_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( rpm --quiet -q pam && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base ); then
var_accounts_max_concurrent_login_sessions='1'
if grep -q '^[^#]*\<maxlogins\>' /etc/security/limits.d/*.conf; then
sed -i "/^[^#]*\<maxlogins\>/ s/maxlogins.*/maxlogins $var_accounts_max_concurrent_login_sessions/" /etc/security/limits.d/*.conf
elif grep -q '^[^#]*\<maxlogins\>' /etc/security/limits.conf; then
sed -i "/^[^#]*\<maxlogins\>/ s/maxlogins.*/maxlogins $var_accounts_max_concurrent_login_sessions/" /etc/security/limits.conf
else
echo "* hard maxlogins $var_accounts_max_concurrent_login_sessions" >> /etc/security/limits.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85555-1
- CJIS-5.5.2.2
- DISA-STIG-SLES-15-020020
- NIST-800-53-AC-10
- NIST-800-53-CM-6(a)
- accounts_max_concurrent_login_sessions
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_accounts_max_concurrent_login_sessions # promote to variable
set_fact:
var_accounts_max_concurrent_login_sessions: !!str 1
tags:
- always
- name: Find /etc/security/limits.d files containing maxlogins configuration
ansible.builtin.find:
paths: /etc/security/limits.d
contains: ^[\s]*\*[\s]+(?:(?:hard)|(?:-))[\s]+maxlogins
patterns: '*.conf'
register: maxlogins
when: ( "pam" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
tags:
- CCE-85555-1
- CJIS-5.5.2.2
- DISA-STIG-SLES-15-020020
- NIST-800-53-AC-10
- NIST-800-53-CM-6(a)
- accounts_max_concurrent_login_sessions
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- restrict_strategy
- name: Limit the Number of Concurrent Login Sessions Allowed Per User in files from
limits.d
ansible.builtin.replace:
dest: '{{ item.path }}'
regexp: ^#?\*.*maxlogins.*
replace: '* hard maxlogins {{ var_accounts_max_concurrent_login_sessions
}}'
with_items:
- '{{ maxlogins.files }}'
when: ( "pam" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
tags:
- CCE-85555-1
- CJIS-5.5.2.2
- DISA-STIG-SLES-15-020020
- NIST-800-53-AC-10
- NIST-800-53-CM-6(a)
- accounts_max_concurrent_login_sessions
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- restrict_strategy
- name: Limit the Number of Concurrent Login Sessions Allowed Per User
ansible.builtin.lineinfile:
state: present
dest: /etc/security/limits.conf
insertbefore: ^# End of file
regexp: ^#?\*.*maxlogins
line: '* hard maxlogins {{ var_accounts_max_concurrent_login_sessions
}}'
create: true
when:
- ( "pam" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
- maxlogins.matched == 0
tags:
- CCE-85555-1
- CJIS-5.5.2.2
- DISA-STIG-SLES-15-020020
- NIST-800-53-AC-10
- NIST-800-53-CM-6(a)
- accounts_max_concurrent_login_sessions
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- restrict_strategy
|
Set Interactive Session Timeout
[ref]ruleSetting the TMOUT option in /etc/profile ensures that
all user sessions will terminate based on inactivity. A value of 0 (zero)
disables the automatic logout feature and is therefore not a compliant setting.
The value of TMOUT should be a positive integer, exported, and read only.
The TMOUT
setting in /etc/profile.d/autologout.sh should read as follows:
TMOUT=900
readonly TMOUT
export TMOUTRationale:Terminating an idle session within a short time period reduces
the window of opportunity for unauthorized personnel to take control of a
management session enabled on the console or console port that has been
left unattended. Identifiers:
CCE-83269-1 References:
1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 3.1.11, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-12, SC-10, AC-2(5), CM-6(a), PR.AC-7, SRG-OS-000163-GPOS-00072, SRG-OS-000029-GPOS-00010, SLES-15-010130, 5.4.4, R32, SLES-15-600600240, 8.6.1, 8.6, SV-234813r1009561_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_accounts_tmout='900'
if [ -f /etc/profile.d/autologout.sh ]; then
if grep --silent '^\s*TMOUT' /etc/profile.d/autologout.sh ; then
sed -i -E "s/^(\s*)TMOUT\s*=\s*(\w|\$)*(.*)$/\1TMOUT=$var_accounts_tmout\3/g" /etc/profile.d/autologout.sh
fi
else
echo -e "\n# Set TMOUT to $var_accounts_tmout per security requirements" >> /etc/profile.d/autologout.sh
echo "TMOUT=$var_accounts_tmout" >> /etc/profile.d/autologout.sh
fi
if ! grep --silent '^\s*readonly TMOUT' /etc/profile.d/autologout.sh ; then
echo "readonly TMOUT" >> /etc/profile.d/autologout.sh
fi
if ! grep --silent '^\s*export TMOUT' /etc/profile.d/autologout.sh ; then
echo "export TMOUT" >> /etc/profile.d/autologout.sh
fi
chmod +x /etc/profile.d/autologout.sh
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83269-1
- DISA-STIG-SLES-15-010130
- NIST-800-171-3.1.11
- NIST-800-53-AC-12
- NIST-800-53-AC-2(5)
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-10
- PCI-DSSv4-8.6
- PCI-DSSv4-8.6.1
- accounts_tmout
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_accounts_tmout # promote to variable
set_fact:
var_accounts_tmout: !!str 900
tags:
- always
- name: Set Interactive Session Timeout
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/profile.d/autologout.sh
create: true
regexp: (?i)^\s*TMOUT=
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/profile.d/autologout.sh
ansible.builtin.lineinfile:
path: /etc/profile.d/autologout.sh
create: true
regexp: (?i)^\s*TMOUT=
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/profile.d/autologout.sh
ansible.builtin.lineinfile:
path: /etc/profile.d/autologout.sh
create: true
regexp: (?i)^\s*TMOUT=
line: TMOUT={{ var_accounts_tmout }}
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83269-1
- DISA-STIG-SLES-15-010130
- NIST-800-171-3.1.11
- NIST-800-53-AC-12
- NIST-800-53-AC-2(5)
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-10
- PCI-DSSv4-8.6
- PCI-DSSv4-8.6.1
- accounts_tmout
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Set Interactive Session Timeout
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/profile.d/autologout.sh
create: true
regexp: (?i)^\s*readonly\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/profile.d/autologout.sh
ansible.builtin.lineinfile:
path: /etc/profile.d/autologout.sh
create: true
regexp: (?i)^\s*readonly\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/profile.d/autologout.sh
ansible.builtin.lineinfile:
path: /etc/profile.d/autologout.sh
create: true
regexp: (?i)^\s*readonly\s+
line: readonly TMOUT
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83269-1
- DISA-STIG-SLES-15-010130
- NIST-800-171-3.1.11
- NIST-800-53-AC-12
- NIST-800-53-AC-2(5)
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-10
- PCI-DSSv4-8.6
- PCI-DSSv4-8.6.1
- accounts_tmout
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Set Interactive Session Timeout
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/profile.d/autologout.sh
create: true
regexp: (?i)^\s*export\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/profile.d/autologout.sh
ansible.builtin.lineinfile:
path: /etc/profile.d/autologout.sh
create: true
regexp: (?i)^\s*export\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/profile.d/autologout.sh
ansible.builtin.lineinfile:
path: /etc/profile.d/autologout.sh
create: true
regexp: (?i)^\s*export\s+
line: export TMOUT
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83269-1
- DISA-STIG-SLES-15-010130
- NIST-800-171-3.1.11
- NIST-800-53-AC-12
- NIST-800-53-AC-2(5)
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-10
- PCI-DSSv4-8.6
- PCI-DSSv4-8.6.1
- accounts_tmout
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Set the permission for /etc/profile.d/autologout.sh
ansible.builtin.file:
path: /etc/profile.d/autologout.sh
mode: '0755'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- lookup('ansible.builtin.file', '/etc/profile.d/autologout.sh', errors='warn')
tags:
- CCE-83269-1
- DISA-STIG-SLES-15-010130
- NIST-800-171-3.1.11
- NIST-800-53-AC-12
- NIST-800-53-AC-2(5)
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-10
- PCI-DSSv4-8.6
- PCI-DSSv4-8.6.1
- accounts_tmout
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
User Initialization Files Must Be Group-Owned By The Primary Group
[ref]ruleChange the group owner of interactive users files to the group found
in /etc/passwd for the user. To change the group owner of a local
interactive user home directory, use the following command:
$ sudo chgrp USER_GROUP /home/USER/.INIT_FILE
This rule ensures every initialization file related to an interactive user
is group-owned by an interactive user.Warning:
Due to OVAL limitation, this rule can report a false negative in a
specific situation where two interactive users swap the group-ownership
of their respective initialization files. Rationale:Local initialization files for interactive users are used to configure the
user's shell environment upon logon. Malicious modification of these files could
compromise accounts upon logon. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
awk -F: '{if ($3 >= 1000 && $3 != 65534) print $4":"$6}' /etc/passwd | while IFS=: read -r gid home; do find -P "$home" -maxdepth 1 -type f -name "\.[^.]*" -exec chgrp -f --no-dereference -- $gid "{}" \;; done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91408-5
- accounts_user_dot_group_ownership
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: User Initialization Files Must Be Group-Owned By The Primary Group - Get interactive
users from passwd file
ansible.builtin.getent:
database: passwd
register: passwd_entries
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91408-5
- accounts_user_dot_group_ownership
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: User Initialization Files Must Be Group-Owned By The Primary Group - Create
list of interactive users with GID and home directory
ansible.builtin.set_fact:
interactive_users: '{{ interactive_users | default([]) + [{''home'': item.value[4],
''gid'': item.value[2]}] }}'
loop: '{{ passwd_entries.ansible_facts.getent_passwd | dict2items }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- item.value[1] | int >= 1000 | int
- item.value[1] | int != 65534 | int
- item.value[4] != ""
tags:
- CCE-91408-5
- accounts_user_dot_group_ownership
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: User Initialization Files Must Be Group-Owned By The Primary Group - Find
dot files in interactive user home directories
ansible.builtin.find:
paths: '{{ item.home }}'
patterns: .*
file_type: file
hidden: true
depth: 1
follow: false
register: user_dotfiles
loop: '{{ interactive_users | default([]) }}'
failed_when: false
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- item.home != ""
tags:
- CCE-91408-5
- accounts_user_dot_group_ownership
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: User Initialization Files Must Be Group-Owned By The Primary Group - Set correct
group ownership for user initialization files
ansible.builtin.file:
path: '{{ item.1.path }}'
group: '{{ item.0.item.gid }}'
follow: false
loop: '{{ user_dotfiles.results | subelements(''files'', skip_missing=True) }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- item.0 is not skipped
- item.1.path is defined
tags:
- CCE-91408-5
- accounts_user_dot_group_ownership
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
User Initialization Files Must Be Owned By the Primary User
[ref]ruleSet the owner of the user initialization files for interactive users to
the primary owner with the following command:
$ sudo chown USER /home/USER/.*
This rule ensures every initialization file related to an interactive user
is owned by an interactive user.Warning:
Due to OVAL limitation, this rule can report a false negative in a
specific situation where two interactive users swap the ownership of
their respective initialization files. Rationale:Local initialization files are used to configure the user's shell environment
upon logon. Malicious modification of these files could compromise accounts upon
logon. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
awk -F: '{if ($3 >= 1000 && $3 != 65534) print $3":"$6}' /etc/passwd | while IFS=: read -r uid home; do find -P "$home" -maxdepth 1 -type f -name "\.[^.]*" -exec chown -f --no-dereference -- $uid "{}" \;; done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91409-3
- accounts_user_dot_user_ownership
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: User Initialization Files Must Be Owned By the Primary User - Get interactive
users from passwd file
ansible.builtin.getent:
database: passwd
register: passwd_entries
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91409-3
- accounts_user_dot_user_ownership
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: User Initialization Files Must Be Owned By the Primary User - Create list
of interactive users with UID and home directory
ansible.builtin.set_fact:
interactive_users: '{{ interactive_users | default([]) + [{''uid'': item.value[1],
''home'': item.value[4], ''username'': item.key}] }}'
loop: '{{ passwd_entries.ansible_facts.getent_passwd | dict2items }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- item.value[1] | int >= 1000 | int
- item.value[1] | int != 65534 | int
- item.value[4] != ""
tags:
- CCE-91409-3
- accounts_user_dot_user_ownership
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: User Initialization Files Must Be Owned By the Primary User - Find dot files
in interactive user home directories
ansible.builtin.find:
paths: '{{ item.home }}'
patterns: .*
file_type: file
hidden: true
depth: 1
follow: false
register: user_dotfiles
loop: '{{ interactive_users | default([]) }}'
failed_when: false
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- item.home != ""
tags:
- CCE-91409-3
- accounts_user_dot_user_ownership
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: User Initialization Files Must Be Owned By the Primary User - Set correct
ownership for user initialization files
ansible.builtin.file:
path: '{{ item.1.path }}'
owner: '{{ item.0.item.username }}'
follow: false
loop: '{{ user_dotfiles.results | subelements(''files'', skip_missing=True) }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- item.0 is not skipped
- item.0 is not failed
- item.0.item is defined
- item.0.item.username is defined
- item.1.path is defined
tags:
- CCE-91409-3
- accounts_user_dot_user_ownership
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure that Users Path Contains Only Local Directories
[ref]ruleEnsure that all interactive user initialization files executable search
path statements do not contain statements that will reference a working
directory other than the users home directory. Rationale:The executable search path (typically the PATH environment variable) contains a
list of directories for the shell to search to find executables. If this path
includes the current working directory (other than the users home directory),
executables in these directories may be executed instead of system commands.
This variable is formatted as a colon-separated list of directories. If there is
an empty entry, such as a leading or trailing colon or two consecutive colons,
this is interpreted as the current working directory. If deviations from the
default system search path for the local interactive user are required, they
must be documented with the Information System Security Officer (ISSO). |
All Interactive Users Home Directories Must Exist
[ref]ruleCreate home directories to all local interactive users that currently do not
have a home directory assigned. Use the following commands to create the user
home directory assigned in /etc/passwd:
$ sudo mkdir /home/USER Rationale:If a local interactive user has a home directory defined that does not exist,
the user may be given access to the / directory as the current working directory
upon logon. This could create a Denial of Service because the user would not be
able to access their logon configuration files, and it may give them visibility
to system files they normally would not be able to access. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
for user in $(awk -F':' '{ if ($3 >= 1000 && $3 != 65534) print $1}' /etc/passwd); do
mkhomedir_helper $user 0077;
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85628-6
- DISA-STIG-SLES-15-040080
- accounts_user_interactive_home_directory_exists
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Get all local users from /etc/passwd
ansible.builtin.getent:
database: passwd
split: ':'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85628-6
- DISA-STIG-SLES-15-040080
- accounts_user_interactive_home_directory_exists
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Create local_users variable from the getent output
ansible.builtin.set_fact:
local_users: '{{ ansible_facts.getent_passwd|dict2items }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85628-6
- DISA-STIG-SLES-15-040080
- accounts_user_interactive_home_directory_exists
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure interactive users have a home directory exists
ansible.builtin.user:
name: '{{ item.key }}'
create_home: true
loop: '{{ local_users }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- item.value[1]|int >= 1000
- item.value[1]|int != 65534
tags:
- CCE-85628-6
- DISA-STIG-SLES-15-040080
- accounts_user_interactive_home_directory_exists
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
All Interactive User Home Directories Must Be Group-Owned By The Primary Group
[ref]ruleChange the group owner of interactive users home directory to the
group found in /etc/passwd. To change the group owner of
interactive users home directory, use the following command:
$ sudo chgrp USER_GROUP /home/USER
This rule ensures every home directory related to an interactive user is
group-owned by an interactive user. It also ensures that interactive users
are group-owners of one and only one home directory.Warning:
Due to OVAL limitation, this rule can report a false negative in a
specific situation where two interactive users swap the group-ownership
of their respective home directories. Rationale:If the Group Identifier (GID) of a local interactive users home directory is
not the same as the primary GID of the user, this would allow unauthorized
access to the users files, and users that share the same group may not be
able to access files that they legitimately should. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
awk -F':' '{ if ($3 >= 1000 && $3 != 65534) system("chgrp -f " $4" "$6) }' /etc/passwd
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Get all local users from /etc/passwd
ansible.builtin.getent:
database: passwd
split: ':'
tags:
- CCE-85711-0
- DISA-STIG-SLES-15-040100
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- file_groupownership_home_directories
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Create local_users variable from the getent output
ansible.builtin.set_fact:
local_users: '{{ ansible_facts.getent_passwd|dict2items }}'
tags:
- CCE-85711-0
- DISA-STIG-SLES-15-040100
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- file_groupownership_home_directories
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Test for existence of home directories to avoid creating them, but only fixing
group ownership
ansible.builtin.stat:
path: '{{ item.value[4] }}'
register: path_exists
loop: '{{ local_users }}'
when:
- item.value[1]|int >= 1000
- item.value[1]|int != 65534
tags:
- CCE-85711-0
- DISA-STIG-SLES-15-040100
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- file_groupownership_home_directories
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure interactive local users are the group-owners of their respective home
directories
ansible.builtin.file:
path: '{{ item.0.value[4] }}'
group: '{{ item.0.value[2] }}'
loop: '{{ local_users|zip(path_exists.results)|list }}'
when: item.1.stat is defined and item.1.stat.exists
tags:
- CCE-85711-0
- DISA-STIG-SLES-15-040100
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- file_groupownership_home_directories
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
All Interactive User Home Directories Must Be Owned By The Primary User
[ref]ruleChange the owner of interactive users home directories to that correct
owner. To change the owner of a interactive users home directory, use
the following command:
$ sudo chown USER /home/USER
This rule ensures every home directory related to an interactive user is
owned by an interactive user. It also ensures that interactive users are
owners of one and only one home directory.Warning:
Due to OVAL limitation, this rule can report a false negative in a
specific situation where two interactive users swap the ownership of
their respective home directories. Rationale:If a local interactive user does not own their home directory, unauthorized
users could access or modify the user's files, and the users may not be able to
access their own files. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
awk -F':' '{ if ($3 >= 1000 && $3 != 65534) system("chown -f " $3" "$6) }' /etc/passwd
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Get all local users from /etc/passwd
ansible.builtin.getent:
database: passwd
split: ':'
tags:
- CCE-91404-4
- file_ownership_home_directories
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Create local_users variable from the getent output
ansible.builtin.set_fact:
local_users: '{{ ansible_facts.getent_passwd|dict2items }}'
tags:
- CCE-91404-4
- file_ownership_home_directories
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Test for existence of home directories to avoid creating them, but only fixing
ownership
ansible.builtin.stat:
path: '{{ item.value[4] }}'
register: path_exists
loop: '{{ local_users }}'
when:
- item.value[1]|int >= 1000
- item.value[1]|int != 65534
tags:
- CCE-91404-4
- file_ownership_home_directories
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure interactive local users are the owners of their respective home directories
ansible.builtin.file:
path: '{{ item.0.value[4] }}'
owner: '{{ item.0.value[1] }}'
loop: '{{ local_users|zip(path_exists.results)|list }}'
when: item.1.stat is defined and item.1.stat.exists
tags:
- CCE-91404-4
- file_ownership_home_directories
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure User Bash History File Has Correct Permissions
[ref]ruleSet the mode of the bash history file to 0600 with the
following command:
$ sudo chmod 0600 /home/USER/.bash_history Rationale:Incorrect permissions may enable malicious users to recover
other users' command history. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
readarray -t interactive_users < <(awk -F: '$3>=1000 {print $1}' /etc/passwd)
readarray -t interactive_users_home < <(awk -F: '$3>=1000 {print $6}' /etc/passwd)
readarray -t interactive_users_shell < <(awk -F: '$3>=1000 {print $7}' /etc/passwd)
USERS_IGNORED_REGEX='nobody|nfsnobody'
for (( i=0; i<"${#interactive_users[@]}"; i++ )); do
if ! grep -qP "$USERS_IGNORED_REGEX" <<< "${interactive_users[$i]}" && \
[ "${interactive_users_shell[$i]}" != "/sbin/nologin" ]; then
chmod u-sx,go= "${interactive_users_home[$i]}/.bash_history"
fi
done
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Ensure User Bash History File Has Correct Permissions - Gather User Info
ansible.builtin.getent:
database: passwd
tags:
- CCE-92554-5
- file_permission_user_bash_history
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure User Bash History File Has Correct Permissions - Check Bash History
Files Existence
ansible.builtin.stat:
path: '{{ item.value[4] }}/.bash_history'
register: bash_history_files
with_dict: '{{ ansible_facts.getent_passwd }}'
when:
- item.value[4] != "/sbin/nologin"
- item.key not in ["nobody", "nfsnobody"]
- item.value[1] | int >= 1000
tags:
- CCE-92554-5
- file_permission_user_bash_history
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure User Bash History File Has Correct Permissions - Fix Bash History Files
Permissions
ansible.builtin.file:
path: '{{ item.stat.path }}'
mode: u-sx,go=
with_items: '{{ bash_history_files.results }}'
when:
- item.stat is defined
- item.stat.exists
tags:
- CCE-92554-5
- file_permission_user_bash_history
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure All User Initialization Files Have Mode 0740 Or Less Permissive
[ref]ruleSet the mode of the user initialization files to 0740 with the
following command:
$ sudo chmod 0740 /home/USER/.INIT_FILE Rationale:Local initialization files are used to configure the user's shell environment
upon logon. Malicious modification of these files could compromise accounts upon
logon. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
var_user_initialization_files_regex='^\.[\w\- ]+$'
readarray -t interactive_users < <(awk -F: '$3>=1000 {print $1}' /etc/passwd)
readarray -t interactive_users_home < <(awk -F: '$3>=1000 {print $6}' /etc/passwd)
readarray -t interactive_users_shell < <(awk -F: '$3>=1000 {print $7}' /etc/passwd)
USERS_IGNORED_REGEX='nobody|nfsnobody'
for (( i=0; i<"${#interactive_users[@]}"; i++ )); do
if ! grep -qP "$USERS_IGNORED_REGEX" <<< "${interactive_users[$i]}" && \
[ "${interactive_users_shell[$i]}" != "/sbin/nologin" ]; then
readarray -t init_files < <(find "${interactive_users_home[$i]}" -maxdepth 1 \
-exec basename {} \; | grep -P "$var_user_initialization_files_regex")
for file in "${init_files[@]}"; do
chmod u-s,g-wxs,o= "${interactive_users_home[$i]}/$file"
done
fi
done
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: XCCDF Value var_user_initialization_files_regex # promote to variable
set_fact:
var_user_initialization_files_regex: !!str ^\.[\w\- ]+$
tags:
- always
- name: Ensure All User Initialization Files Have Mode 0740 Or Less Permissive - Gather
User Info
ansible.builtin.getent:
database: passwd
tags:
- CCE-85630-2
- DISA-STIG-SLES-15-040110
- file_permission_user_init_files
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure All User Initialization Files Have Mode 0740 Or Less Permissive - Find
Init Files
ansible.builtin.find:
paths: '{{ item.value[4] }}'
pattern: '{{ var_user_initialization_files_regex }}'
hidden: true
use_regex: true
with_dict: '{{ ansible_facts.getent_passwd }}'
when:
- item.value[4] != "/sbin/nologin"
- item.key not in ["nobody", "nfsnobody"]
- item.value[1] | int >= 1000
register: found_init_files
tags:
- CCE-85630-2
- DISA-STIG-SLES-15-040110
- file_permission_user_init_files
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure All User Initialization Files Have Mode 0740 Or Less Permissive - Fix
Init Files Permissions
ansible.builtin.file:
path: '{{ item.1.path }}'
mode: u-s,g-wxs,o=
loop: '{{ q(''ansible.builtin.subelements'', found_init_files.results, ''files'',
{''skip_missing'': True}) }}'
tags:
- CCE-85630-2
- DISA-STIG-SLES-15-040110
- file_permission_user_init_files
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
All Interactive User Home Directories Must Have mode 0750 Or Less Permissive
[ref]ruleChange the mode of interactive users home directories to 0750. To
change the mode of interactive users home directory, use the
following command:
$ sudo chmod 0750 /home/USER Rationale:Excessive permissions on local interactive user home directories may allow
unauthorized access to user files by other users. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
for home_dir in $(awk -F':' '{ if ($3 >= 1000 && $3 != 65534 && $6 != "/") print $6 }' /etc/passwd); do
# Only update the permissions when necessary. This will avoid changing the inode timestamp when
# the permission is already defined as expected, therefore not impacting in possible integrity
# check systems that also check inodes timestamps.
find "$home_dir" -maxdepth 0 -perm /7027 \! -type l -exec chmod u-s,g-w-s,o=- {} \;
done
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Get all local users from /etc/passwd
ansible.builtin.getent:
database: passwd
split: ':'
tags:
- CCE-85629-4
- DISA-STIG-SLES-15-040090
- file_permissions_home_directories
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Create local_users variable from the getent output
ansible.builtin.set_fact:
local_users: '{{ ansible_facts.getent_passwd|dict2items }}'
tags:
- CCE-85629-4
- DISA-STIG-SLES-15-040090
- file_permissions_home_directories
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Test for existence home directories to avoid creating them.
ansible.builtin.stat:
path: '{{ item.value[4] }}'
register: path_exists
loop: '{{ local_users }}'
when:
- item.value[1]|int >= 1000
- item.value[1]|int != 65534
- item.value[4] != "/"
tags:
- CCE-85629-4
- DISA-STIG-SLES-15-040090
- file_permissions_home_directories
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure interactive local users have proper permissions on their respective
home directories
ansible.builtin.file:
path: '{{ item.0.value[4] }}'
mode: u-s,g-w-s,o=-
follow: false
recurse: false
loop: '{{ local_users|zip(path_exists.results)|list }}'
when: item.1.stat is defined and item.1.stat.exists
tags:
- CCE-85629-4
- DISA-STIG-SLES-15-040090
- file_permissions_home_directories
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
AppArmor
[ref]groupMany security vulnerabilities result from bugs in trusted programs. A trusted
program runs with privileges that attackers want to possess. The program fails
to keep that trust if there is a bug in the program that allows the attacker to
acquire said privilege.
AppArmor® is an application security solution designed specifically to apply
privilege confinement to suspect programs. AppArmor allows the administrator to
specify the domain of activities the program can perform by developing a
security profile. A security profile is a listing of files that the program may
access and the operations the program may perform. AppArmor secures
applications by enforcing good application behavior without relying on attack
signatures, so it can prevent attacks even if previously unknown
vulnerabilities are being exploited.
For more information on using AppArmor, see
https://www.suse.com/documentation/sles-12/book_security/data/cha_apparmor_intro.html. |
| contains 4 rules |
Ensure AppArmor is installed
[ref]ruleAppArmor provide Mandatory Access Controls. Rationale:Without a Mandatory Access Control system installed only the default
Discretionary Access Control system will be available. Remediation script: (show)
[[packages]]
name = "patterns-base-apparmor"
version = "*"
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_patterns-base-apparmor
class install_patterns-base-apparmor {
package { 'patterns-base-apparmor':
ensure => 'installed',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then
zypper install -y "patterns-base-apparmor"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Ensure patterns-base-apparmor is installed
ansible.builtin.package:
name: patterns-base-apparmor
state: present
when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
tags:
- CCE-92594-1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_apparmor_installed
|
Enforce all AppArmor Profiles
[ref]ruleAppArmor profiles define what resources applications are able to access.
To set all profiles to enforce mode run the following command:
$ sudo aa-enforce /etc/apparmor.d/*
To list unconfined processes run the following command:
$ sudo aa-unconfined
Any unconfined processes may need to have a profile created or activated
for them and then be restarted.Rationale:Security configuration requirements vary from site to site. Some sites may
mandate a policy that is stricter than the default policy, which is perfectly
acceptable. This recommendation is intended to ensure that any policies that
exist on the system are activated. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { ( [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q apparmor-profiles ); }; then
# make sure apparmor-utils is installed for aa-complain and aa-enforce
zypper install -y "apparmor-utils"
# Ensure all AppArmor Profiles are enforcing
apparmor_parser -q -r /etc/apparmor.d/
aa-enforce /etc/apparmor.d/*
UNCONFINED=$(aa-unconfined)
if [ ! -z "$UNCONFINED" ]
then
echo -e "***WARNING***: There are some unconfined processes:"
echo -e "----------------------------"
echo "The may need to have a profile created or activated for them and then be restarted."
for PROCESS in "${UNCONFINED[@]}"
do
echo "$PROCESS"
done
echo -e "----------------------------"
echo "The may need to have a profile created or activated for them and then be restarted."
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92536-2
- all_apparmor_profiles_enforced
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Enforce all AppArmor Profiles - Ensure all AppArmor Profiles are reloaded
ansible.builtin.command: apparmor_parser -q -r /etc/apparmor.d/
when:
- ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
- ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
and "apparmor-profiles" in ansible_facts.packages )
tags:
- CCE-92536-2
- all_apparmor_profiles_enforced
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Enforce all AppArmor Profiles - Ensure all AppArmor Profiles are enforcing
ansible.builtin.command: aa-enforce /etc/apparmor.d/*
when:
- ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
- ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
and "apparmor-profiles" in ansible_facts.packages )
tags:
- CCE-92536-2
- all_apparmor_profiles_enforced
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Enforce all AppArmor Profiles - Collect unconfined processes
ansible.builtin.command: aa-unconfined
register: unconfined_processes
when:
- ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
- ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
and "apparmor-profiles" in ansible_facts.packages )
tags:
- CCE-92536-2
- all_apparmor_profiles_enforced
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Enforce all AppArmor Profiles - Provide details about unconfined processes
ansible.builtin.assert:
that:
- unconfined_processes.stdout_lines | length > 0
success_msg: The process {{ item }} may need to have a profile created or activated
for them and then be restarted.
fail_msg: ''
with_items: '{{ unconfined_processes.stdout_lines }}'
when:
- ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
- ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
and "apparmor-profiles" in ansible_facts.packages )
- unconfined_processes is not skipped
tags:
- CCE-92536-2
- all_apparmor_profiles_enforced
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
All AppArmor Profiles are in enforce or complain mode
[ref]ruleAppArmor profiles define what resources applications are able to access.
To set all profiles to either enforce or complain mode
run the following command to set all profiles to enforce mode:
$ sudo aa-enforce /etc/apparmor.d/*
run the following command to set all profiles to complain mode:
$ sudo aa-complain /etc/apparmor.d/*
To list unconfined processes run the following command:
$ sudo aa-unconfined
Any unconfined processes may need to have a profile created or activated
for them and then be restarted.Rationale:Security configuration requirements vary from site to site. Some sites may
mandate a policy that is stricter than the default policy, which is perfectly
acceptable. This recommendation is intended to ensure that any policies that
exist on the system are activated. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && { ( [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q apparmor-profiles ); }; then
var_apparmor_mode='complain'
# make sure apparmor-utils is installed for aa-complain and aa-enforce
zypper install -y "apparmor-utils"
# Reload all AppArmor profiles
apparmor_parser -q -r /etc/apparmor.d/
# Set the mode
APPARMOR_MODE="$var_apparmor_mode"
if [ "$APPARMOR_MODE" = "enforce" ]
then
# Set all profiles to enforce mode
aa-enforce /etc/apparmor.d/*
fi
if [ "$APPARMOR_MODE" = "complain" ]
then
# Set all profiles to complain mode
aa-complain /etc/apparmor.d/*
fi
if [ "$APPARMOR_MODE" = "keep_existing_mode" ]
then
echo "***WARNING***: This remediation will not modify any existing AppArmor profiles."
fi
UNCONFINED=$(aa-unconfined)
if [ ! -z "$UNCONFINED" ]
then
echo -e "***WARNING***: There are some unconfined processes:"
echo -e "----------------------------"
echo "The may need to have a profile created or activated for them and then be restarted."
for PROCESS in "${UNCONFINED[@]}"
do
echo "$PROCESS"
done
echo -e "----------------------------"
echo "The may need to have a profile created or activated for them and then be restarted."
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92548-7
- all_apparmor_profiles_in_enforce_complain_mode
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_apparmor_mode # promote to variable
set_fact:
var_apparmor_mode: !!str complain
tags:
- always
- name: All AppArmor Profiles are in enforce or complain mode - Ensure all AppArmor
Profiles are reloaded
ansible.builtin.command: apparmor_parser -q -r /etc/apparmor.d/
when:
- ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
- ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
and "apparmor-profiles" in ansible_facts.packages )
tags:
- CCE-92548-7
- all_apparmor_profiles_in_enforce_complain_mode
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: All AppArmor Profiles are in enforce or complain mode - Set all AppArmor profiles
to enforce mode
ansible.builtin.command: aa-enforce /etc/apparmor.d/*
when:
- ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
- ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
and "apparmor-profiles" in ansible_facts.packages )
- var_apparmor_mode == 'enforce'
tags:
- CCE-92548-7
- all_apparmor_profiles_in_enforce_complain_mode
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: All AppArmor Profiles are in enforce or complain mode - Set all AppArmor profiles
to complain mode
ansible.builtin.command: aa-complain /etc/apparmor.d/*
when:
- ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
- ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
and "apparmor-profiles" in ansible_facts.packages )
- var_apparmor_mode == 'complain'
tags:
- CCE-92548-7
- all_apparmor_profiles_in_enforce_complain_mode
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: All AppArmor Profiles are in enforce or complain mode - Collect unconfined
processes
ansible.builtin.command: aa-unconfined
register: unconfined_processes
when:
- ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
- ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
and "apparmor-profiles" in ansible_facts.packages )
tags:
- CCE-92548-7
- all_apparmor_profiles_in_enforce_complain_mode
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: All AppArmor Profiles are in enforce or complain mode - Provide details about
unconfined processes
ansible.builtin.assert:
that:
- unconfined_processes.stdout_lines | length > 0
success_msg: The process {{ item }} may need to have a profile created or activated
for them and then be restarted.
fail_msg: ''
with_items: '{{ unconfined_processes.stdout_lines }}'
when:
- ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
- ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
and "apparmor-profiles" in ansible_facts.packages )
- unconfined_processes is not skipped
tags:
- CCE-92548-7
- all_apparmor_profiles_in_enforce_complain_mode
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure AppArmor is Active and Configured
[ref]ruleVerify that the Apparmor tool is configured to
control whitelisted applications and user home directory access
control.
The apparmor service can be enabled with the following command:
$ sudo systemctl enable apparmor.service Rationale:Using a whitelist provides a configuration management method for allowing
the execution of only authorized software. Using only authorized software
decreases risk by limiting the number of potential vulnerabilities.
The organization must identify authorized software programs and permit
execution of authorized software by adding each authorized program to the
"pam_apparmor" exception policy. The process used to identify software
programs that are authorized to execute on organizational information
systems is commonly referred to as whitelisting.
Verification of whitelisted software occurs prior to execution or at system
startup.
Users' home directories/folders may contain information of a sensitive
nature. Nonprivileged users should coordinate any sharing of information
with a System Administrator (SA) through shared resources.
Apparmor can confine users to their home directory, not allowing them to
make any changes outside of their own home directories. Confining users to
their home directory will minimize the risk of sharing information. Identifiers:
CCE-85752-4 References:
AC-3(4), AC-6(8), AC-6(10), CM-7(5)(b), CM-7(2), SC-7(21), CM-6(a), SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000312-GPOS-00124, SRG-OS-000324-GPOS-00125, SRG-OS-000326-GPOS-00126, SRG-OS-000370-GPOS-00155, SRG-OS-000480-GPOS-00230, SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00231, SRG-OS-000480-GPOS-00232, SLES-15-010390, 1.7.1.2, R45, SLES-15-150450030, SV-234848r958702_rule Remediation script: (show)
[customizations.services]
enabled = ["apparmor"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include enable_apparmor
class enable_apparmor {
service {'apparmor':
enable => true,
ensure => 'running',
}
}
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then
# Enable apparmor
/usr/bin/systemctl enable "apparmor"
if [[ $(/usr/bin/systemctl is-system-running) != "offline" ]]; then
/usr/bin/systemctl start "apparmor"
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
if /usr/bin/systemctl --failed | grep -q "apparmor"; then
/usr/bin/systemctl reset-failed "apparmor"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
- name: Start apparmor.service
ansible.builtin.systemd:
name: apparmor.service
state: started
enabled: true
when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
tags:
- CCE-85752-4
- DISA-STIG-SLES-15-010390
- NIST-800-53-AC-3(4)
- NIST-800-53-AC-6(10)
- NIST-800-53-AC-6(8)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(2)
- NIST-800-53-CM-7(5)(b)
- NIST-800-53-SC-7(21)
- apparmor_configured
- medium_severity
|
GRUB2 bootloader configuration
[ref]groupDuring the boot process, the boot loader is
responsible for starting the execution of the kernel and passing
options to it. The boot loader allows for the selection of
different kernels - possibly on different partitions or media.
The default SUSE Linux Enterprise 15 boot loader for x86 systems is called GRUB2.
Options it can pass to the kernel include single-user mode, which
provides root access without any authentication, and the ability to
disable SELinux. To prevent local users from modifying the boot
parameters and endangering security, protect the boot loader configuration
with a password and ensure its configuration file's permissions
are set properly. |
| contains 5 rules |
Non-UEFI GRUB2 bootloader configuration
[ref]groupNon-UEFI GRUB2 bootloader configuration |
| contains 4 rules |
Verify /boot/grub2/grub.cfg Group Ownership
[ref]ruleThe file /boot/grub2/grub.cfg should
be group-owned by the root group to prevent
destruction or modification of the file.
To properly set the group owner of /boot/grub2/grub.cfg, run the command:
$ sudo chgrp root /boot/grub2/grub.cfg
Rationale:The root group is a highly-privileged group. Furthermore, the group-owner of this
file should not have any access privileges anyway. Identifiers:
CCE-85849-8 References:
12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-7.1, SRG-OS-000480-GPOS-00227, 1.5.2, R29, SLES-15-150600030, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if ( rpm --quiet -q grub2 && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base ) && { ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ); }; then
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/boot/grub2/grub.cfg" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /boot/grub2/grub.cfg
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85849-8
- CJIS-5.5.2.2
- NIST-800-171-3.4.5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-7.1
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_grub2_cfg
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_groupowner_grub2_cfg_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_grub2_cfg_newgroup: '0'
when:
- ( "grub2" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
- not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
)
tags:
- CCE-85849-8
- CJIS-5.5.2.2
- NIST-800-171-3.4.5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-7.1
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_grub2_cfg
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /boot/grub2/grub.cfg
ansible.builtin.stat:
path: /boot/grub2/grub.cfg
register: file_exists
when:
- ( "grub2" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
- not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
)
tags:
- CCE-85849-8
- CJIS-5.5.2.2
- NIST-800-171-3.4.5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-7.1
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_grub2_cfg
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /boot/grub2/grub.cfg
ansible.builtin.file:
path: /boot/grub2/grub.cfg
follow: false
group: '{{ file_groupowner_grub2_cfg_newgroup }}'
when:
- ( "grub2" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
- not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-85849-8
- CJIS-5.5.2.2
- NIST-800-171-3.4.5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-7.1
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_grub2_cfg
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify /boot/grub2/grub.cfg User Ownership
[ref]ruleThe file /boot/grub2/grub.cfg should
be owned by the root user to prevent destruction
or modification of the file.
To properly set the owner of /boot/grub2/grub.cfg, run the command:
$ sudo chown root /boot/grub2/grub.cfg
Rationale:Only root should be able to modify important boot parameters. Identifiers:
CCE-85848-0 References:
12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-7.1, SRG-OS-000480-GPOS-00227, 1.5.2, R29, SLES-15-150600030, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if ( rpm --quiet -q grub2 && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base ) && { ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ); }; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/boot/grub2/grub.cfg" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /boot/grub2/grub.cfg
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85848-0
- CJIS-5.5.2.2
- NIST-800-171-3.4.5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-7.1
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_grub2_cfg
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_owner_grub2_cfg_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_grub2_cfg_newown: '0'
when:
- ( "grub2" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
- not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
)
tags:
- CCE-85848-0
- CJIS-5.5.2.2
- NIST-800-171-3.4.5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-7.1
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_grub2_cfg
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /boot/grub2/grub.cfg
ansible.builtin.stat:
path: /boot/grub2/grub.cfg
register: file_exists
when:
- ( "grub2" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
- not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
)
tags:
- CCE-85848-0
- CJIS-5.5.2.2
- NIST-800-171-3.4.5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-7.1
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_grub2_cfg
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /boot/grub2/grub.cfg
ansible.builtin.file:
path: /boot/grub2/grub.cfg
follow: false
owner: '{{ file_owner_grub2_cfg_newown }}'
when:
- ( "grub2" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
- not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-85848-0
- CJIS-5.5.2.2
- NIST-800-171-3.4.5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-7.1
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_grub2_cfg
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify /boot/grub2/grub.cfg Permissions
[ref]ruleFile permissions for /boot/grub2/grub.cfg should be set to 600.
To properly set the permissions of /boot/grub2/grub.cfg, run the command:
$ sudo chmod 600 /boot/grub2/grub.cfg Rationale:Proper permissions ensure that only the root user can modify important boot
parameters. Identifiers:
CCE-91426-7 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 1.5.2, R29, SLES-15-150600030, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if ( rpm --quiet -q grub2 && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base ) && { ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ); }; then
chmod u-xs,g-xwrs,o-xwrt /boot/grub2/grub.cfg
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91426-7
- NIST-800-171-3.4.5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_grub2_cfg
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /boot/grub2/grub.cfg
ansible.builtin.stat:
path: /boot/grub2/grub.cfg
register: file_exists
when:
- ( "grub2" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
- not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
)
tags:
- CCE-91426-7
- NIST-800-171-3.4.5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_grub2_cfg
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xwrs,o-xwrt on /boot/grub2/grub.cfg
ansible.builtin.file:
path: /boot/grub2/grub.cfg
mode: u-xs,g-xwrs,o-xwrt
when:
- ( "grub2" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
- not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91426-7
- NIST-800-171-3.4.5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_grub2_cfg
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Set Boot Loader Password in grub2
[ref]ruleThe grub2 boot loader should have a superuser account and password
protection enabled to protect boot-time settings.
Since plaintext passwords are a security risk, generate a hash for the password
by running the following command:
# grub2-mkpasswd-pbkdf2
When prompted, enter the password that was selected.
Using the hash from the output, modify the /etc/grub.d/40_custom
file with the following content:
set superusers="boot"
password_pbkdf2 boot grub.pbkdf2.sha512.VeryLongString
NOTE: the bootloader superuser account and password MUST differ from the
root account and password.
Once the superuser password has been added,
update the
grub.cfg file by running:
grub2-mkconfig -o /boot/grub2/grub.cfg Warning:
To prevent hard-coded passwords, automatic remediation of this control is not available. Remediation
must be automated as a component of machine provisioning, or followed manually as outlined above.
Also, do NOT manually add the superuser account and password to the
grub.cfg file as the grub2-mkconfig command overwrites this file. Rationale:Password protection on the boot loader configuration ensures
users with physical access cannot trivially alter
important bootloader settings. These include which kernel to use,
and whether to enter single-user mode. Identifiers:
CCE-83274-1 References:
1, 11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10, 3.4.5, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CM-6(a), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.PT-3, FIA_UAU.1, SRG-OS-000080-GPOS-00048, SLES-15-010190, 1.5.1, R5, SLES-15-150600015, SV-234819r958472_rule |
UEFI GRUB2 bootloader configuration
[ref]groupUEFI GRUB2 bootloader configuration Warning:
UEFI generally uses vfat file systems, which does not support Unix-style permissions
managed by chmod command. In this case, in order to change file permissions for files
within /boot/efi it is necessary to update the mount options in /etc/fstab file and
reboot the system. |
| contains 1 rule |
Set the UEFI Boot Loader Password
[ref]ruleThe grub2 boot loader should have a superuser account and password
protection enabled to protect boot-time settings.
Since plaintext passwords are a security risk, generate a hash for the password
by running the following command:
# grub2-mkpasswd-pbkdf2
When prompted, enter the password that was selected.
Using the hash from the output, modify the /etc/grub.d/40_custom
file with the following content:
set superusers="boot"
password_pbkdf2 boot grub.pbkdf2.sha512.VeryLongString
NOTE: the bootloader superuser account and password MUST differ from the
root account and password.
Once the superuser password has been added,
update the
grub.cfg file by running:
grub2-mkconfig -o /boot/grub2/grub.cfg Warning:
To prevent hard-coded passwords, automatic remediation of this control is not available. Remediation
must be automated as a component of machine provisioning, or followed manually as outlined above.
Also, do NOT manually add the superuser account and password to the
grub.cfg file as the grub2-mkconfig command overwrites this file. Rationale:Password protection on the boot loader configuration ensures
users with physical access cannot trivially alter
important bootloader settings. These include which kernel to use,
and whether to enter single-user mode. Identifiers:
CCE-83275-8 References:
11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.4.5, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), PR.AC-4, PR.AC-6, PR.PT-3, FIA_UAU.1, SRG-OS-000080-GPOS-00048, SLES-15-010200, 1.5.1, R5, SLES-15-150600015, SV-234820r958472_rule |
Kernel Configuration
[ref]groupContains rules that check the kernel configuration that was used to build it. |
| contains 5 rules |
Enable seccomp to safely compute untrusted bytecode
[ref]ruleThis kernel feature is useful for number crunching applications that may need to compute
untrusted bytecode during their execution. By using pipes or other transports made available
to the process as file descriptors supporting the read/write syscalls, it's possible to isolate
those applications in their own address space using seccomp.
The configuration that was used to build kernel is available at /boot/config-*.
To check the configuration value for CONFIG_SECCOMP, run the following command:
grep CONFIG_SECCOMP /boot/config-*
For each kernel installed, a line with value "y" should be returned.
Warning:
There is no remediation for this besides re-compiling the kernel with the appropriate value for the config. Rationale:seccomp enables the ability to filter system calls made by an application, effectively
isolating the system's resources from it.
|
Enable use of Berkeley Packet Filter with seccomp
[ref]ruleEnable tasks to build secure computing environments defined in terms of Berkeley Packet Filter
programs which implement task-defined system call filtering polices.
The configuration that was used to build kernel is available at /boot/config-*.
To check the configuration value for CONFIG_SECCOMP_FILTER, run the following command:
grep CONFIG_SECCOMP_FILTER /boot/config-*
For each kernel installed, a line with value "y" should be returned.
Warning:
There is no remediation for this besides re-compiling the kernel with the appropriate value for the config. Rationale:Use of BPF filters allows for expressive filtering of system calls using a filter program
language with a long history of being exposed to userland. |
Enable different security models
[ref]ruleThis allows you to choose different security modules to be configured into your kernel.
The configuration that was used to build kernel is available at /boot/config-*.
To check the configuration value for CONFIG_SECURITY, run the following command:
grep CONFIG_SECURITY /boot/config-*
For each kernel installed, a line with value "y" should be returned.
Warning:
There is no remediation for this besides re-compiling the kernel with the appropriate value for the config. Rationale:This is enables kernel security primitives required by the LSM framework. |
Disable mutable hooks
[ref]ruleEnsure kernel structures associated with LSMs are always mapped as read-only after system boot.
The configuration that was used to build kernel is available at /boot/config-*.
To check the configuration value for CONFIG_SECURITY_WRITABLE_HOOKS, run the following command:
grep CONFIG_SECURITY_WRITABLE_HOOKS /boot/config-*
Configs with value 'n' are not explicitly set in the file, so either commented lines or no
lines should be returned.
Warning:
There is no remediation for this besides re-compiling the kernel with the appropriate value for the config. Rationale:If CONFIG_SECURITY_WRITABLE_HOOKS is enabled, then hooks can be loaded at runtime and
being able to manipulate hooks is a way to bypass all LSMs. |
Enable Yama support
[ref]ruleThis enables support for LSM module Yama, which extends DAC support with additional system-wide
security settings beyond regular Linux discretionary access controls. The module will limit the
use of the system call ptrace().
The configuration that was used to build kernel is available at /boot/config-*.
To check the configuration value for CONFIG_SECURITY_YAMA, run the following command:
grep CONFIG_SECURITY_YAMA /boot/config-*
For each kernel installed, a line with value "y" should be returned.
Warning:
There is no remediation for this besides re-compiling the kernel with the appropriate value for the config. Rationale:Unrestricted usage of ptrace allows compromised binaries to run ptrace
on another processes of the user. |
Configure Syslog
[ref]groupThe syslog service has been the default Unix logging mechanism for
many years. It has a number of downsides, including inconsistent log format,
lack of authentication for received messages, and lack of authentication,
encryption, or reliable transport for messages sent over a network. However,
due to its long history, syslog is a de facto standard which is supported by
almost all Unix applications.
In SUSE Linux Enterprise 15, rsyslog has replaced ksyslogd as the
syslog daemon of choice, and it includes some additional security features
such as reliable, connection-oriented (i.e. TCP) transmission of logs, the
option to log to database formats, and the encryption of log data en route to
a central logging server.
This section discusses how to configure rsyslog for
best effect, and how to use tools provided with the system to maintain and
monitor logs. |
| contains 23 rules |
Ensure Proper Configuration of Log Files
[ref]groupThe file /etc/rsyslog.conf controls where log message are written.
These are controlled by lines called rules, which consist of a
selector and an action.
These rules are often customized depending on the role of the system, the
requirements of the environment, and whatever may enable
the administrator to most effectively make use of log data.
The default rules in SUSE Linux Enterprise 15 are:
*.info;mail.none;authpriv.none;cron.none /var/log/messages
authpriv.* /var/log/secure
mail.* -/var/log/maillog
cron.* /var/log/cron
*.emerg *
uucp,news.crit /var/log/spooler
local7.* /var/log/boot.log
See the man page rsyslog.conf(5) for more information.
Note that the rsyslog daemon can be configured to use a timestamp format that
some log processing programs may not understand. If this occurs,
edit the file /etc/rsyslog.conf and add or edit the following line:
$ ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat |
| contains 4 rules |
Ensure Log Files Are Owned By Appropriate Group
[ref]ruleThe group-owner of all log files written by
rsyslog should be root.
These log files are determined by the second part of each Rule line in
/etc/rsyslog.conf and typically all appear in /var/log.
For each log file LOGFILE referenced in /etc/rsyslog.conf,
run the following command to inspect the file's group owner:
$ ls -l LOGFILE
If the owner is not root,
run the following command to
correct this:
$ sudo chgrp root LOGFILE Rationale:The log files generated by rsyslog contain valuable information regarding system
configuration, user authentication, and other such information. Log files should be
protected from unauthorized access. Identifiers:
CCE-85838-1 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-10.5.1, Req-10.5.2, 4.2.1.3, R71, SLES-15-750300300, 0988, 1405, 10.3.2, 10.3 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && rpm --quiet -q rsyslog; then
# List of log file paths to be inspected for correct permissions
# * Primarily inspect log file paths listed in /etc/rsyslog.conf
RSYSLOG_ETC_CONFIG="/etc/rsyslog.conf"
# * And also the log file paths listed after rsyslog's $IncludeConfig directive
# (store the result into array for the case there's shell glob used as value of IncludeConfig)
readarray -t OLD_INC < <(grep -e "\$IncludeConfig[[:space:]]\+[^[:space:];]\+" /etc/rsyslog.conf | cut -d ' ' -f 2)
readarray -t RSYSLOG_INCLUDE_CONFIG < <(for INCPATH in "${OLD_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
readarray -t NEW_INC < <(sed -n '/^\s*include(/,/)/Ip' /etc/rsyslog.conf | sed -n 's@.*file\s*=\s*"\([/[:alnum:][:punct:]]*\)".*@\1@Ip')
readarray -t RSYSLOG_INCLUDE < <(for INCPATH in "${NEW_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
# Declare an array to hold the final list of different log file paths
declare -a LOG_FILE_PATHS
# Array to hold all rsyslog config entries
RSYSLOG_CONFIGS=()
RSYSLOG_CONFIGS=("${RSYSLOG_ETC_CONFIG}" "${RSYSLOG_INCLUDE_CONFIG[@]}" "${RSYSLOG_INCLUDE[@]}")
# Get full list of files to be checked
# RSYSLOG_CONFIGS may contain globs such as
# /etc/rsyslog.d/*.conf /etc/rsyslog.d/*.frule
# So, loop over the entries in RSYSLOG_CONFIGS and use find to get the list of included files.
RSYSLOG_CONFIG_FILES=()
for ENTRY in "${RSYSLOG_CONFIGS[@]}"
do
# If directory, rsyslog will search for config files in recursively.
# However, files in hidden sub-directories or hidden files will be ignored.
if [ -d "${ENTRY}" ]
then
readarray -t FINDOUT < <(find "${ENTRY}" -not -path '*/.*' -type f)
RSYSLOG_CONFIG_FILES+=("${FINDOUT[@]}")
elif [ -f "${ENTRY}" ]
then
RSYSLOG_CONFIG_FILES+=("${ENTRY}")
else
echo "Invalid include object: ${ENTRY}"
fi
done
# Browse each file selected above as containing paths of log files
# ('/etc/rsyslog.conf' and '/etc/rsyslog.d/*.conf' in the default configuration)
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
# From each of these files extract just particular log file path(s), thus:
# * Ignore lines starting with space (' '), comment ('#"), or variable syntax ('$') characters,
# * Ignore empty lines,
# * Strip quotes and closing brackets from paths.
# * Ignore paths that match /dev|/etc.*\.conf, as those are paths, but likely not log files
# * From the remaining valid rows select only fields constituting a log file path
# Text file column is understood to represent a log file path if and only if all of the
# following are met:
# * it contains at least one slash '/' character,
# * it is preceded by space
# * it doesn't contain space (' '), colon (':'), and semicolon (';') characters
# Search log file for path(s) only in case it exists!
if [[ -f "${LOG_FILE}" ]]
then
NORMALIZED_CONFIG_FILE_LINES=$(sed -e "/^[#|$]/d" "${LOG_FILE}")
LINES_WITH_PATHS=$(grep '[^/]*\s\+\S*/\S\+$' <<< "${NORMALIZED_CONFIG_FILE_LINES}")
FILTERED_PATHS=$(awk '{if(NF>=2&&($NF~/^\//||$NF~/^-\//)){sub(/^-\//,"/",$NF);print $NF}}' <<< "${LINES_WITH_PATHS}")
CLEANED_PATHS=$(sed -e "s/[\"')]//g; /\\/etc.*\.conf/d; /\\/dev\\//d" <<< "${FILTERED_PATHS}")
MATCHED_ITEMS=$(sed -e "/^$/d" <<< "${CLEANED_PATHS}")
# Since above sed command might return more than one item (delimited by newline), split
# the particular matches entries into new array specific for this log file
readarray -t ARRAY_FOR_LOG_FILE <<< "$MATCHED_ITEMS"
# Concatenate the two arrays - previous content of $LOG_FILE_PATHS array with
# items from newly created array for this log file
LOG_FILE_PATHS+=("${ARRAY_FOR_LOG_FILE[@]}")
# Delete the temporary array
unset ARRAY_FOR_LOG_FILE
fi
done
# Check for RainerScript action log format which might be also multiline so grep regex is a bit
# curly:
# extract possibly multiline action omfile expressions
# extract File="logfile" expression
# match only "logfile" expression
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
ACTION_OMFILE_LINES=$(grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" "${LOG_FILE}")
OMFILE_LINES=$(echo "${ACTION_OMFILE_LINES}"| grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)")
LOG_FILE_PATHS+=("$(echo "${OMFILE_LINES}"| grep -oE "\"([/[:alnum:][:punct:]]*)\""|tr -d "\"")")
done
# Ensure the correct attribute if file exists
FILE_CMD="chgrp"
for LOG_FILE_PATH in "${LOG_FILE_PATHS[@]}"
do
# Sanity check - if particular $LOG_FILE_PATH is empty string, skip it from further processing
if [ -z "$LOG_FILE_PATH" ]
then
continue
fi
$FILE_CMD "root" "$LOG_FILE_PATH"
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85838-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_groupownership
- name: Ensure Log Files Are Owned By Appropriate Group - Set rsyslog logfile configuration
facts
ansible.builtin.set_fact:
rsyslog_etc_config: /etc/rsyslog.conf
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85838-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_groupownership
- name: Ensure Log Files Are Owned By Appropriate Group - Get IncludeConfig directive
ansible.builtin.shell: |
set -o pipefail
grep -e '$IncludeConfig' {{ rsyslog_etc_config }} | cut -d ' ' -f 2 || true
register: rsyslog_old_inc
changed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85838-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_groupownership
- name: Ensure Log Files Are Owned By Appropriate Group - Get include files directives
ansible.builtin.shell: |
set -o pipefail
awk '/)/{f=0} /include\(/{f=1} f{ nf=gensub("^(include\\(|\\s*)file=\"(\\S+)\".*","\\2",1); if($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
register: rsyslog_new_inc
changed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85838-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_groupownership
- name: Ensure Log Files Are Owned By Appropriate Group - Aggregate rsyslog includes
ansible.builtin.set_fact:
include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
}}'
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
tags:
- CCE-85838-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_groupownership
- name: Ensure Log Files Are Owned By Appropriate Group - List all config files
ansible.builtin.find:
paths: '{{ item | dirname }}'
patterns: '{{ item | basename }}'
hidden: false
follow: true
loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- include_config_output is defined
register: rsyslog_config_files
failed_when: false
changed_when: false
tags:
- CCE-85838-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_groupownership
- name: Ensure Log Files Are Owned By Appropriate Group - Extract log files old format
ansible.builtin.shell: |
set -o pipefail
grep -oP '^[^(\s|#|\$)]+[\s]+.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ item.1.path }} | \
awk '{print $NF}' | \
sed -e 's/^-//' || true
loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
register: log_files_old
changed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_config_files is not skipped
tags:
- CCE-85838-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_groupownership
- name: Ensure Log Files Are Owned By Appropriate Group - Extract log files new format
ansible.builtin.shell: |
set -o pipefail
grep -ozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
grep -aoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
tr -d "\""|| true
loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
register: log_files_new
changed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_config_files is not skipped
tags:
- CCE-85838-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_groupownership
- name: Ensure Log Files Are Owned By Appropriate Group - Sum all log files found
ansible.builtin.set_fact:
log_files: '{{ log_files_new.results | map(attribute=''stdout_lines'') | list
| flatten | unique + log_files_old.results | map(attribute=''stdout_lines'')
| list | flatten | unique }}'
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85838-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_groupownership
- name: Ensure Log Files Are Owned By Appropriate Group -Setup log files attribute
ansible.builtin.file:
path: '{{ item }}'
group: root
state: file
loop: '{{ log_files | list | flatten | unique }}'
failed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85838-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_groupownership
|
Ensure Log Files Are Owned By Appropriate User
[ref]ruleThe owner of all log files written by
rsyslog should be
root.
These log files are determined by the second part of each Rule line in
/etc/rsyslog.conf and typically all appear in /var/log.
For each log file LOGFILE referenced in /etc/rsyslog.conf,
run the following command to inspect the file's owner:
$ ls -l LOGFILE
If the owner is not
root,
run the following command to
correct this:
$ sudo chown root LOGFILE Rationale:The log files generated by rsyslog contain valuable information regarding system
configuration, user authentication, and other such information. Log files should be
protected from unauthorized access. Identifiers:
CCE-85839-9 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-10.5.1, Req-10.5.2, 4.2.1.3, R71, SLES-15-750300300, 0988, 1405, 10.3.2, 10.3 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && rpm --quiet -q rsyslog; then
# List of log file paths to be inspected for correct permissions
# * Primarily inspect log file paths listed in /etc/rsyslog.conf
RSYSLOG_ETC_CONFIG="/etc/rsyslog.conf"
# * And also the log file paths listed after rsyslog's $IncludeConfig directive
# (store the result into array for the case there's shell glob used as value of IncludeConfig)
readarray -t OLD_INC < <(grep -e "\$IncludeConfig[[:space:]]\+[^[:space:];]\+" /etc/rsyslog.conf | cut -d ' ' -f 2)
readarray -t RSYSLOG_INCLUDE_CONFIG < <(for INCPATH in "${OLD_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
readarray -t NEW_INC < <(sed -n '/^\s*include(/,/)/Ip' /etc/rsyslog.conf | sed -n 's@.*file\s*=\s*"\([/[:alnum:][:punct:]]*\)".*@\1@Ip')
readarray -t RSYSLOG_INCLUDE < <(for INCPATH in "${NEW_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
# Declare an array to hold the final list of different log file paths
declare -a LOG_FILE_PATHS
# Array to hold all rsyslog config entries
RSYSLOG_CONFIGS=()
RSYSLOG_CONFIGS=("${RSYSLOG_ETC_CONFIG}" "${RSYSLOG_INCLUDE_CONFIG[@]}" "${RSYSLOG_INCLUDE[@]}")
# Get full list of files to be checked
# RSYSLOG_CONFIGS may contain globs such as
# /etc/rsyslog.d/*.conf /etc/rsyslog.d/*.frule
# So, loop over the entries in RSYSLOG_CONFIGS and use find to get the list of included files.
RSYSLOG_CONFIG_FILES=()
for ENTRY in "${RSYSLOG_CONFIGS[@]}"
do
# If directory, rsyslog will search for config files in recursively.
# However, files in hidden sub-directories or hidden files will be ignored.
if [ -d "${ENTRY}" ]
then
readarray -t FINDOUT < <(find "${ENTRY}" -not -path '*/.*' -type f)
RSYSLOG_CONFIG_FILES+=("${FINDOUT[@]}")
elif [ -f "${ENTRY}" ]
then
RSYSLOG_CONFIG_FILES+=("${ENTRY}")
else
echo "Invalid include object: ${ENTRY}"
fi
done
# Browse each file selected above as containing paths of log files
# ('/etc/rsyslog.conf' and '/etc/rsyslog.d/*.conf' in the default configuration)
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
# From each of these files extract just particular log file path(s), thus:
# * Ignore lines starting with space (' '), comment ('#"), or variable syntax ('$') characters,
# * Ignore empty lines,
# * Strip quotes and closing brackets from paths.
# * Ignore paths that match /dev|/etc.*\.conf, as those are paths, but likely not log files
# * From the remaining valid rows select only fields constituting a log file path
# Text file column is understood to represent a log file path if and only if all of the
# following are met:
# * it contains at least one slash '/' character,
# * it is preceded by space
# * it doesn't contain space (' '), colon (':'), and semicolon (';') characters
# Search log file for path(s) only in case it exists!
if [[ -f "${LOG_FILE}" ]]
then
NORMALIZED_CONFIG_FILE_LINES=$(sed -e "/^[#|$]/d" "${LOG_FILE}")
LINES_WITH_PATHS=$(grep '[^/]*\s\+\S*/\S\+$' <<< "${NORMALIZED_CONFIG_FILE_LINES}")
FILTERED_PATHS=$(awk '{if(NF>=2&&($NF~/^\//||$NF~/^-\//)){sub(/^-\//,"/",$NF);print $NF}}' <<< "${LINES_WITH_PATHS}")
CLEANED_PATHS=$(sed -e "s/[\"')]//g; /\\/etc.*\.conf/d; /\\/dev\\//d" <<< "${FILTERED_PATHS}")
MATCHED_ITEMS=$(sed -e "/^$/d" <<< "${CLEANED_PATHS}")
# Since above sed command might return more than one item (delimited by newline), split
# the particular matches entries into new array specific for this log file
readarray -t ARRAY_FOR_LOG_FILE <<< "$MATCHED_ITEMS"
# Concatenate the two arrays - previous content of $LOG_FILE_PATHS array with
# items from newly created array for this log file
LOG_FILE_PATHS+=("${ARRAY_FOR_LOG_FILE[@]}")
# Delete the temporary array
unset ARRAY_FOR_LOG_FILE
fi
done
# Check for RainerScript action log format which might be also multiline so grep regex is a bit
# curly:
# extract possibly multiline action omfile expressions
# extract File="logfile" expression
# match only "logfile" expression
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
ACTION_OMFILE_LINES=$(grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" "${LOG_FILE}")
OMFILE_LINES=$(echo "${ACTION_OMFILE_LINES}"| grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)")
LOG_FILE_PATHS+=("$(echo "${OMFILE_LINES}"| grep -oE "\"([/[:alnum:][:punct:]]*)\""|tr -d "\"")")
done
# Ensure the correct attribute if file exists
FILE_CMD="chown"
for LOG_FILE_PATH in "${LOG_FILE_PATHS[@]}"
do
# Sanity check - if particular $LOG_FILE_PATH is empty string, skip it from further processing
if [ -z "$LOG_FILE_PATH" ]
then
continue
fi
$FILE_CMD "root" "$LOG_FILE_PATH"
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85839-9
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_ownership
- name: Ensure Log Files Are Owned By Appropriate User - Set rsyslog logfile configuration
facts
ansible.builtin.set_fact:
rsyslog_etc_config: /etc/rsyslog.conf
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85839-9
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_ownership
- name: Ensure Log Files Are Owned By Appropriate User - Get IncludeConfig directive
ansible.builtin.shell: |
set -o pipefail
grep -e '$IncludeConfig' {{ rsyslog_etc_config }} | cut -d ' ' -f 2 || true
register: rsyslog_old_inc
changed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85839-9
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_ownership
- name: Ensure Log Files Are Owned By Appropriate User - Get include files directives
ansible.builtin.shell: |
set -o pipefail
awk '/)/{f=0} /include\(/{f=1} f{ nf=gensub("^(include\\(|\\s*)file=\"(\\S+)\".*","\\2",1); if($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
register: rsyslog_new_inc
changed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85839-9
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_ownership
- name: Ensure Log Files Are Owned By Appropriate User - Aggregate rsyslog includes
ansible.builtin.set_fact:
include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
}}'
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
tags:
- CCE-85839-9
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_ownership
- name: Ensure Log Files Are Owned By Appropriate User - List all config files
ansible.builtin.find:
paths: '{{ item | dirname }}'
patterns: '{{ item | basename }}'
hidden: false
follow: true
loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- include_config_output is defined
register: rsyslog_config_files
failed_when: false
changed_when: false
tags:
- CCE-85839-9
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_ownership
- name: Ensure Log Files Are Owned By Appropriate User - Extract log files old format
ansible.builtin.shell: |
set -o pipefail
grep -oP '^[^(\s|#|\$)]+[\s]+.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ item.1.path }} | \
awk '{print $NF}' | \
sed -e 's/^-//' || true
loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
register: log_files_old
changed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_config_files is not skipped
tags:
- CCE-85839-9
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_ownership
- name: Ensure Log Files Are Owned By Appropriate User - Extract log files new format
ansible.builtin.shell: |
set -o pipefail
grep -ozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
grep -aoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
tr -d "\""|| true
loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
register: log_files_new
changed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_config_files is not skipped
tags:
- CCE-85839-9
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_ownership
- name: Ensure Log Files Are Owned By Appropriate User - Sum all log files found
ansible.builtin.set_fact:
log_files: '{{ log_files_new.results | map(attribute=''stdout_lines'') | list
| flatten | unique + log_files_old.results | map(attribute=''stdout_lines'')
| list | flatten | unique }}'
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85839-9
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_ownership
- name: Ensure Log Files Are Owned By Appropriate User -Setup log files attribute
ansible.builtin.file:
path: '{{ item }}'
owner: root
state: file
loop: '{{ log_files | list | flatten | unique }}'
failed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85839-9
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_ownership
|
Ensure System Log Files Have Correct Permissions
[ref]ruleThe file permissions for all log files written by rsyslog should
be set to 640, or more restrictive. These log files are determined by the
second part of each Rule line in /etc/rsyslog.conf and typically
all appear in /var/log. For each log file LOGFILE
referenced in /etc/rsyslog.conf, run the following command to
inspect the file's permissions:
$ ls -l LOGFILE
If the permissions are not 640 or more restrictive, run the following
command to correct this:
$ sudo chmod 640 LOGFILE "Rationale:Log files can contain valuable information regarding system
configuration. If the system log files are not protected unauthorized
users could change the logged data, eliminating their forensic value. Identifiers:
CCE-85837-3 References:
CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), Req-10.5.1, Req-10.5.2, 4.2.1.3, R71, SLES-15-750300300, 0988, 1405, 10.3.1, 10.3 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && rpm --quiet -q rsyslog; then
# List of log file paths to be inspected for correct permissions
# * Primarily inspect log file paths listed in /etc/rsyslog.conf
RSYSLOG_ETC_CONFIG="/etc/rsyslog.conf"
# * And also the log file paths listed after rsyslog's $IncludeConfig directive
# (store the result into array for the case there's shell glob used as value of IncludeConfig)
readarray -t OLD_INC < <(grep -e "\$IncludeConfig[[:space:]]\+[^[:space:];]\+" /etc/rsyslog.conf | cut -d ' ' -f 2)
readarray -t RSYSLOG_INCLUDE_CONFIG < <(for INCPATH in "${OLD_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
readarray -t NEW_INC < <(sed -n '/^\s*include(/,/)/Ip' /etc/rsyslog.conf | sed -n 's@.*file\s*=\s*"\([/[:alnum:][:punct:]]*\)".*@\1@Ip')
readarray -t RSYSLOG_INCLUDE < <(for INCPATH in "${NEW_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
# Declare an array to hold the final list of different log file paths
declare -a LOG_FILE_PATHS
# Array to hold all rsyslog config entries
RSYSLOG_CONFIGS=()
RSYSLOG_CONFIGS=("${RSYSLOG_ETC_CONFIG}" "${RSYSLOG_INCLUDE_CONFIG[@]}" "${RSYSLOG_INCLUDE[@]}")
# Get full list of files to be checked
# RSYSLOG_CONFIGS may contain globs such as
# /etc/rsyslog.d/*.conf /etc/rsyslog.d/*.frule
# So, loop over the entries in RSYSLOG_CONFIGS and use find to get the list of included files.
RSYSLOG_CONFIG_FILES=()
for ENTRY in "${RSYSLOG_CONFIGS[@]}"
do
# If directory, rsyslog will search for config files in recursively.
# However, files in hidden sub-directories or hidden files will be ignored.
if [ -d "${ENTRY}" ]
then
readarray -t FINDOUT < <(find "${ENTRY}" -not -path '*/.*' -type f)
RSYSLOG_CONFIG_FILES+=("${FINDOUT[@]}")
elif [ -f "${ENTRY}" ]
then
RSYSLOG_CONFIG_FILES+=("${ENTRY}")
else
echo "Invalid include object: ${ENTRY}"
fi
done
# Browse each file selected above as containing paths of log files
# ('/etc/rsyslog.conf' and '/etc/rsyslog.d/*.conf' in the default configuration)
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
# From each of these files extract just particular log file path(s), thus:
# * Ignore lines starting with space (' '), comment ('#"), or variable syntax ('$') characters,
# * Ignore empty lines,
# * Strip quotes and closing brackets from paths.
# * Ignore paths that match /dev|/etc.*\.conf, as those are paths, but likely not log files
# * From the remaining valid rows select only fields constituting a log file path
# Text file column is understood to represent a log file path if and only if all of the
# following are met:
# * it contains at least one slash '/' character,
# * it is preceded by space
# * it doesn't contain space (' '), colon (':'), and semicolon (';') characters
# Search log file for path(s) only in case it exists!
if [[ -f "${LOG_FILE}" ]]
then
NORMALIZED_CONFIG_FILE_LINES=$(sed -e "/^[#|$]/d" "${LOG_FILE}")
LINES_WITH_PATHS=$(grep '[^/]*\s\+\S*/\S\+$' <<< "${NORMALIZED_CONFIG_FILE_LINES}")
FILTERED_PATHS=$(awk '{if(NF>=2&&($NF~/^\//||$NF~/^-\//)){sub(/^-\//,"/",$NF);print $NF}}' <<< "${LINES_WITH_PATHS}")
CLEANED_PATHS=$(sed -e "s/[\"')]//g; /\\/etc.*\.conf/d; /\\/dev\\//d" <<< "${FILTERED_PATHS}")
MATCHED_ITEMS=$(sed -e "/^$/d" <<< "${CLEANED_PATHS}")
# Since above sed command might return more than one item (delimited by newline), split
# the particular matches entries into new array specific for this log file
readarray -t ARRAY_FOR_LOG_FILE <<< "$MATCHED_ITEMS"
# Concatenate the two arrays - previous content of $LOG_FILE_PATHS array with
# items from newly created array for this log file
LOG_FILE_PATHS+=("${ARRAY_FOR_LOG_FILE[@]}")
# Delete the temporary array
unset ARRAY_FOR_LOG_FILE
fi
done
# Check for RainerScript action log format which might be also multiline so grep regex is a bit
# curly:
# extract possibly multiline action omfile expressions
# extract File="logfile" expression
# match only "logfile" expression
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
ACTION_OMFILE_LINES=$(grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" "${LOG_FILE}")
OMFILE_LINES=$(echo "${ACTION_OMFILE_LINES}"| grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)")
LOG_FILE_PATHS+=("$(echo "${OMFILE_LINES}"| grep -oE "\"([/[:alnum:][:punct:]]*)\""|tr -d "\"")")
done
# Ensure the correct attribute if file exists
FILE_CMD="chmod"
for LOG_FILE_PATH in "${LOG_FILE_PATHS[@]}"
do
# Sanity check - if particular $LOG_FILE_PATH is empty string, skip it from further processing
if [ -z "$LOG_FILE_PATH" ]
then
continue
fi
$FILE_CMD "0640" "$LOG_FILE_PATH"
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85837-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_permissions
- name: Ensure System Log Files Have Correct Permissions - Set rsyslog logfile configuration
facts
ansible.builtin.set_fact:
rsyslog_etc_config: /etc/rsyslog.conf
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85837-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_permissions
- name: Ensure System Log Files Have Correct Permissions - Get IncludeConfig directive
ansible.builtin.shell: |
set -o pipefail
grep -e '$IncludeConfig' {{ rsyslog_etc_config }} | cut -d ' ' -f 2 || true
register: rsyslog_old_inc
changed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85837-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_permissions
- name: Ensure System Log Files Have Correct Permissions - Get include files directives
ansible.builtin.shell: |
set -o pipefail
awk '/)/{f=0} /include\(/{f=1} f{ nf=gensub("^(include\\(|\\s*)file=\"(\\S+)\".*","\\2",1); if($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
register: rsyslog_new_inc
changed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85837-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_permissions
- name: Ensure System Log Files Have Correct Permissions - Aggregate rsyslog includes
ansible.builtin.set_fact:
include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
}}'
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
tags:
- CCE-85837-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_permissions
- name: Ensure System Log Files Have Correct Permissions - List all config files
ansible.builtin.find:
paths: '{{ item | dirname }}'
patterns: '{{ item | basename }}'
hidden: false
follow: true
loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- include_config_output is defined
register: rsyslog_config_files
failed_when: false
changed_when: false
tags:
- CCE-85837-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_permissions
- name: Ensure System Log Files Have Correct Permissions - Extract log files old format
ansible.builtin.shell: |
set -o pipefail
grep -oP '^[^(\s|#|\$)]+[\s]+.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ item.1.path }} | \
awk '{print $NF}' | \
sed -e 's/^-//' || true
loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
register: log_files_old
changed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_config_files is not skipped
tags:
- CCE-85837-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_permissions
- name: Ensure System Log Files Have Correct Permissions - Extract log files new format
ansible.builtin.shell: |
set -o pipefail
grep -ozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
grep -aoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
tr -d "\""|| true
loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
register: log_files_new
changed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_config_files is not skipped
tags:
- CCE-85837-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_permissions
- name: Ensure System Log Files Have Correct Permissions - Sum all log files found
ansible.builtin.set_fact:
log_files: '{{ log_files_new.results | map(attribute=''stdout_lines'') | list
| flatten | unique + log_files_old.results | map(attribute=''stdout_lines'')
| list | flatten | unique }}'
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85837-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_permissions
- name: Ensure System Log Files Have Correct Permissions -Setup log files attribute
ansible.builtin.file:
path: '{{ item }}'
mode: '0640'
state: file
loop: '{{ log_files | list | flatten | unique }}'
failed_when: false
when:
- '"rsyslog" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85837-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_permissions
|
Ensure logging is configured
[ref]ruleThe /etc/rsyslog.conf and /etc/rsyslog.d/*.conf files
specifies rules for logging and which files are to be used to log certain
classes of messages. Warning:
This rule does not come with remediation as there is no one way to solve the problem, and
the requirement from CIS specification does not require one particular way, but persuades
the system administrator to perform configuration suitable for the specific environment.
This also means that the OVAL check is too generic, and the user most probably should
perform additional manual verification. Rationale:A great deal of important security-related information is sent via
rsyslog (e.g., successful and failed su attempts, failed login attempts,
root login attempts, etc.). |
systemd-journald
[ref]groupsystemd-journald is a system service that collects and stores
logging data. It creates and maintains structured, indexed
journals based on logging information that is received from a
variety of sources.
For more information on systemd-journald and additional systemd-journald configuration options, see
https://systemd.io/. |
| contains 10 rules |
Install systemd-journal-remote Package
[ref]ruleJournald (via systemd-journal-remote ) supports the ability to send
log events it gathers to a remote log host or to receive messages
from remote hosts, thus enabling centralised log management. Rationale:Storing log data on a remote host protects log integrity from local
attacks. If an attacker gains root access on the local system, they
could tamper with or remove log data that is stored on the local system. Remediation script: (show)
[[packages]]
name = "systemd-journal-remote"
version = "*"
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_systemd-journal-remote
class install_systemd-journal-remote {
package { 'systemd-journal-remote':
ensure => 'installed',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
zypper install -y "systemd-journal-remote"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92598-2
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_systemd-journal-remote_installed
- name: Ensure systemd-journal-remote is installed
ansible.builtin.package:
name: systemd-journal-remote
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92598-2
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_systemd-journal-remote_installed
|
Enable systemd-journal-upload Service
[ref]ruleThe systemd-journal-upload service is part of the systemd-journal-remote package
and enables centralized logging by uploading local systemd journal entries to a remote log
server via HTTPS. This service acts as a client that pushes journal data to a remote host
running the systemd-journal-remote receiver service.
The systemd-journal-upload service can be enabled with the following command:
$ sudo systemctl enable systemd-journal-upload.service Warning:
The systemd-journal-upload service will fail to start if the remote server URL is not configured.
Edit /etc/systemd/journal-upload.conf to configure the remote server URL. Rationale:Centralized logging through systemd-journal-upload is essential for security monitoring,
incident response, and compliance requirements. Storing log data on a remote host protects log
integrity from local attacks. If an attacker gains root access on the local system, they could
tamper with or remove log data stored locally to hide their activities. Remote logging ensures
that audit trails remain intact even if the local system is compromised. Additionally,
centralized logs facilitate correlation of events across multiple systems, enabling better
detection of distributed attacks and security incidents. Remediation script: (show)
[customizations.services]
enabled = ["systemd-journal-upload"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include enable_systemd-journal-upload
class enable_systemd-journal-upload {
service {'systemd-journal-upload':
enable => true,
ensure => 'running',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { ( [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q systemd-journal-remote ); }; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" unmask 'systemd-journal-upload.service'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" start 'systemd-journal-upload.service'
fi
"$SYSTEMCTL_EXEC" enable 'systemd-journal-upload.service'
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92604-8
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_systemd-journal-upload_enabled
- name: Enable systemd-journal-upload Service - Enable service systemd-journal-upload
block:
- name: Gather the package facts
ansible.builtin.package_facts:
manager: auto
- name: Enable systemd-journal-upload Service - Enable Service systemd-journal-upload
ansible.builtin.systemd:
name: systemd-journal-upload
enabled: true
state: started
masked: false
when:
- '"systemd-journal-remote" in ansible_facts.packages'
tags:
- CCE-92604-8
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_systemd-journal-upload_enabled
- special_service_block
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
and "systemd-journal-remote" in ansible_facts.packages )
|
Enable systemd-journald Service
[ref]ruleThe systemd-journald service is an essential component of
systemd.
The systemd-journald service can be enabled with the following command:
$ sudo systemctl enable systemd-journald.service Rationale:In the event of a system failure, SUSE Linux Enterprise 15 must preserve any information necessary to determine cause of failure and any information necessary to return to operations with least disruption to system processes. Remediation script: (show)
[customizations.services]
enabled = ["systemd-journald"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include enable_systemd-journald
class enable_systemd-journald {
service {'systemd-journald':
enable => true,
ensure => 'running',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" unmask 'systemd-journald.service'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" start 'systemd-journald.service'
fi
"$SYSTEMCTL_EXEC" enable 'systemd-journald.service'
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92605-5
- NIST-800-53-SC-24
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_systemd-journald_enabled
- name: Enable systemd-journald Service - Enable service systemd-journald
block:
- name: Gather the package facts
ansible.builtin.package_facts:
manager: auto
- name: Enable systemd-journald Service - Enable Service systemd-journald
ansible.builtin.systemd:
name: systemd-journald
enabled: true
state: started
masked: false
when:
- '"systemd" in ansible_facts.packages'
tags:
- CCE-92605-5
- NIST-800-53-SC-24
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_systemd-journald_enabled
- special_service_block
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
Ensure journald is configured to compress large log files
[ref]ruleThe journald system can compress large log files to avoid fill the system disk. Rationale:Log files that are not properly compressed run the risk of growing so large that they fill up the log partition. Valuable logging information could be lost if the log partition becomes full. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
found=false
# set value in all files if they contain section or key
for f in $(echo -n "/etc/systemd/journal.d/complianceascode_hardening.conf /etc/systemd/journal.d/*.conf /etc/systemd/journald.conf"); do
if [ ! -e "$f" ]; then
continue
fi
# find key in section and change value
if grep -qzosP "[[:space:]]*\[Journal\]([^\n\[]*\n+)+?[[:space:]]*Compress" "$f"; then
if ! grep -qPz "Compress=yes" "$f"; then
sed -i "s/Compress[^(\n)]*/Compress=yes/" "$f"
fi
found=true
# find section and add key = value to it
elif grep -qs "[[:space:]]*\[Journal\]" "$f"; then
sed -i "/[[:space:]]*\[Journal\]/a Compress=yes" "$f"
found=true
fi
done
# if section not in any file, append section with key = value to FIRST file in files parameter
if ! $found ; then
file=$(echo "/etc/systemd/journal.d/complianceascode_hardening.conf /etc/systemd/journal.d/*.conf /etc/systemd/journald.conf" | cut -f1 -d ' ')
mkdir -p "$(dirname "$file")"
echo -e "[Journal]\nCompress=yes" >> "$file"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91377-2
- journald_compress
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald is configured to compress large log files - Search for a section
in files
ansible.builtin.find:
paths: '{{item.path}}'
patterns: '{{item.pattern}}'
contains: ^\s*\[Journal\]
read_whole_file: true
use_regex: true
register: systemd_dropin_files_with_section
loop:
- path: '{{ ''/etc/systemd/journald.conf'' | dirname }}'
pattern: '{{ ''/etc/systemd/journald.conf'' | basename | regex_escape }}'
- path: /etc/systemd/journal.d
pattern: .*\.conf
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91377-2
- journald_compress
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald is configured to compress large log files - Count number of
files which contain the correct section
ansible.builtin.set_fact:
count_of_systemd_dropin_files_with_section: '{{systemd_dropin_files_with_section.results
| map(attribute=''matched'') | list | map(''int'') | sum}}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91377-2
- journald_compress
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald is configured to compress large log files - Add missing configuration
to correct section
community.general.ini_file:
path: '{{item}}'
section: Journal
option: Compress
value: 'yes'
state: present
no_extra_spaces: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- count_of_systemd_dropin_files_with_section | int > 0
loop: '{{systemd_dropin_files_with_section.results | sum(attribute=''files'', start=[])
| map(attribute=''path'') | list }}'
tags:
- CCE-91377-2
- journald_compress
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald is configured to compress large log files - Add configuration
to new remediation file
community.general.ini_file:
path: /etc/systemd/journal.d/complianceascode_hardening.conf
section: Journal
option: Compress
value: 'yes'
state: present
no_extra_spaces: true
create: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- count_of_systemd_dropin_files_with_section | int == 0
tags:
- CCE-91377-2
- journald_compress
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure journald ForwardToSyslog is disabled
[ref]ruleData from journald should be kept in the confines of the service and not forwarded to other services. Rationale:If journald is the method for capturing logs, all logs of the system should be handled by journald and not forwarded to other logging mechanisms. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q systemd; }; then
found=false
# set value in all files if they contain section or key
for f in $(echo -n "/etc/systemd/journal.d/complianceascode_hardening.conf /etc/systemd/journal.d/*.conf /etc/systemd/journald.conf"); do
if [ ! -e "$f" ]; then
continue
fi
# find key in section and change value
if grep -qzosP "[[:space:]]*\[Journal\]([^\n\[]*\n+)+?[[:space:]]*ForwardToSyslog" "$f"; then
if ! grep -qPz "ForwardToSyslog=no" "$f"; then
sed -i "s/ForwardToSyslog[^(\n)]*/ForwardToSyslog=no/" "$f"
fi
found=true
# find section and add key = value to it
elif grep -qs "[[:space:]]*\[Journal\]" "$f"; then
sed -i "/[[:space:]]*\[Journal\]/a ForwardToSyslog=no" "$f"
found=true
fi
done
# if section not in any file, append section with key = value to FIRST file in files parameter
if ! $found ; then
file=$(echo "/etc/systemd/journal.d/complianceascode_hardening.conf /etc/systemd/journal.d/*.conf /etc/systemd/journald.conf" | cut -f1 -d ' ')
mkdir -p "$(dirname "$file")"
echo -e "[Journal]\nForwardToSyslog=no" >> "$file"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92566-9
- journald_disable_forward_to_syslog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald ForwardToSyslog is disabled - Search for a section in files
ansible.builtin.find:
paths: '{{item.path}}'
patterns: '{{item.pattern}}'
contains: ^\s*\[Journal\]
read_whole_file: true
use_regex: true
register: systemd_dropin_files_with_section
loop:
- path: '{{ ''/etc/systemd/journald.conf'' | dirname }}'
pattern: '{{ ''/etc/systemd/journald.conf'' | basename | regex_escape }}'
- path: /etc/systemd/journal.d
pattern: .*\.conf
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
tags:
- CCE-92566-9
- journald_disable_forward_to_syslog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald ForwardToSyslog is disabled - Count number of files which
contain the correct section
ansible.builtin.set_fact:
count_of_systemd_dropin_files_with_section: '{{systemd_dropin_files_with_section.results
| map(attribute=''matched'') | list | map(''int'') | sum}}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
tags:
- CCE-92566-9
- journald_disable_forward_to_syslog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald ForwardToSyslog is disabled - Add missing configuration to
correct section
community.general.ini_file:
path: '{{item}}'
section: Journal
option: ForwardToSyslog
value: 'no'
state: present
no_extra_spaces: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
- count_of_systemd_dropin_files_with_section | int > 0
loop: '{{systemd_dropin_files_with_section.results | sum(attribute=''files'', start=[])
| map(attribute=''path'') | list }}'
tags:
- CCE-92566-9
- journald_disable_forward_to_syslog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald ForwardToSyslog is disabled - Add configuration to new remediation
file
community.general.ini_file:
path: /etc/systemd/journal.d/complianceascode_hardening.conf
section: Journal
option: ForwardToSyslog
value: 'no'
state: present
no_extra_spaces: true
create: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
- count_of_systemd_dropin_files_with_section | int == 0
tags:
- CCE-92566-9
- journald_disable_forward_to_syslog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure journald is configured to send logs to rsyslog
[ref]ruleData from journald may be stored in volatile memory or persisted locally.
Utilities exist to accept remote export of journald logs. Rationale:Storing log data on a remote host protects log integrity from local attacks. If an attacker gains root access on the local system, they could tamper with or remove log data that is stored on the local system. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
found=false
# set value in all files if they contain section or key
for f in $(echo -n "/etc/systemd/journal.d/complianceascode_hardening.conf /etc/systemd/journal.d/*.conf /etc/systemd/journald.conf"); do
if [ ! -e "$f" ]; then
continue
fi
# find key in section and change value
if grep -qzosP "[[:space:]]*\[Journal\]([^\n\[]*\n+)+?[[:space:]]*ForwardToSyslog" "$f"; then
if ! grep -qPz "ForwardToSyslog=yes" "$f"; then
sed -i "s/ForwardToSyslog[^(\n)]*/ForwardToSyslog=yes/" "$f"
fi
found=true
# find section and add key = value to it
elif grep -qs "[[:space:]]*\[Journal\]" "$f"; then
sed -i "/[[:space:]]*\[Journal\]/a ForwardToSyslog=yes" "$f"
found=true
fi
done
# if section not in any file, append section with key = value to FIRST file in files parameter
if ! $found ; then
file=$(echo "/etc/systemd/journal.d/complianceascode_hardening.conf /etc/systemd/journal.d/*.conf /etc/systemd/journald.conf" | cut -f1 -d ' ')
mkdir -p "$(dirname "$file")"
echo -e "[Journal]\nForwardToSyslog=yes" >> "$file"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91376-4
- journald_forward_to_syslog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald is configured to send logs to rsyslog - Search for a section
in files
ansible.builtin.find:
paths: '{{item.path}}'
patterns: '{{item.pattern}}'
contains: ^\s*\[Journal\]
read_whole_file: true
use_regex: true
register: systemd_dropin_files_with_section
loop:
- path: '{{ ''/etc/systemd/journald.conf'' | dirname }}'
pattern: '{{ ''/etc/systemd/journald.conf'' | basename | regex_escape }}'
- path: /etc/systemd/journal.d
pattern: .*\.conf
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91376-4
- journald_forward_to_syslog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald is configured to send logs to rsyslog - Count number of files
which contain the correct section
ansible.builtin.set_fact:
count_of_systemd_dropin_files_with_section: '{{systemd_dropin_files_with_section.results
| map(attribute=''matched'') | list | map(''int'') | sum}}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91376-4
- journald_forward_to_syslog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald is configured to send logs to rsyslog - Add missing configuration
to correct section
community.general.ini_file:
path: '{{item}}'
section: Journal
option: ForwardToSyslog
value: 'yes'
state: present
no_extra_spaces: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- count_of_systemd_dropin_files_with_section | int > 0
loop: '{{systemd_dropin_files_with_section.results | sum(attribute=''files'', start=[])
| map(attribute=''path'') | list }}'
tags:
- CCE-91376-4
- journald_forward_to_syslog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald is configured to send logs to rsyslog - Add configuration
to new remediation file
community.general.ini_file:
path: /etc/systemd/journal.d/complianceascode_hardening.conf
section: Journal
option: ForwardToSyslog
value: 'yes'
state: present
no_extra_spaces: true
create: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- count_of_systemd_dropin_files_with_section | int == 0
tags:
- CCE-91376-4
- journald_forward_to_syslog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure journald is configured to write log files to persistent disk
[ref]ruleThe journald system may store log files in volatile memory or locally on disk.
If the logs are only stored in volatile memory they will be lost upon reboot. Rationale:Log files contain valuable data and need to be persistent to aid in possible investigations. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
found=false
# set value in all files if they contain section or key
for f in $(echo -n "/etc/systemd/journal.d/complianceascode_hardening.conf /etc/systemd/journal.d/*.conf /etc/systemd/journald.conf"); do
if [ ! -e "$f" ]; then
continue
fi
# find key in section and change value
if grep -qzosP "[[:space:]]*\[Journal\]([^\n\[]*\n+)+?[[:space:]]*Storage" "$f"; then
if ! grep -qPz "Storage=persistent" "$f"; then
sed -i "s/Storage[^(\n)]*/Storage=persistent/" "$f"
fi
found=true
# find section and add key = value to it
elif grep -qs "[[:space:]]*\[Journal\]" "$f"; then
sed -i "/[[:space:]]*\[Journal\]/a Storage=persistent" "$f"
found=true
fi
done
# if section not in any file, append section with key = value to FIRST file in files parameter
if ! $found ; then
file=$(echo "/etc/systemd/journal.d/complianceascode_hardening.conf /etc/systemd/journal.d/*.conf /etc/systemd/journald.conf" | cut -f1 -d ' ')
mkdir -p "$(dirname "$file")"
echo -e "[Journal]\nStorage=persistent" >> "$file"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91378-0
- journald_storage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald is configured to write log files to persistent disk - Search
for a section in files
ansible.builtin.find:
paths: '{{item.path}}'
patterns: '{{item.pattern}}'
contains: ^\s*\[Journal\]
read_whole_file: true
use_regex: true
register: systemd_dropin_files_with_section
loop:
- path: '{{ ''/etc/systemd/journald.conf'' | dirname }}'
pattern: '{{ ''/etc/systemd/journald.conf'' | basename | regex_escape }}'
- path: /etc/systemd/journal.d
pattern: .*\.conf
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91378-0
- journald_storage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald is configured to write log files to persistent disk - Count
number of files which contain the correct section
ansible.builtin.set_fact:
count_of_systemd_dropin_files_with_section: '{{systemd_dropin_files_with_section.results
| map(attribute=''matched'') | list | map(''int'') | sum}}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91378-0
- journald_storage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald is configured to write log files to persistent disk - Add
missing configuration to correct section
community.general.ini_file:
path: '{{item}}'
section: Journal
option: Storage
value: persistent
state: present
no_extra_spaces: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- count_of_systemd_dropin_files_with_section | int > 0
loop: '{{systemd_dropin_files_with_section.results | sum(attribute=''files'', start=[])
| map(attribute=''path'') | list }}'
tags:
- CCE-91378-0
- journald_storage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure journald is configured to write log files to persistent disk - Add
configuration to new remediation file
community.general.ini_file:
path: /etc/systemd/journal.d/complianceascode_hardening.conf
section: Journal
option: Storage
value: persistent
state: present
no_extra_spaces: true
create: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- count_of_systemd_dropin_files_with_section | int == 0
tags:
- CCE-91378-0
- journald_storage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Disable systemd-journal-remote Socket
[ref]ruleJournald supports the ability to receive messages from remote hosts,
thus acting as a log server. Clients should not receive data from
other hosts.
NOTE:
The same package, systemd-journal-remote , is used for both sending
logs to remote hosts and receiving incoming logs.
With regards to receiving logs, there are two Systemd unit files;
systemd-journal-remote.socket and systemd-journal-remote.service. Rationale:If a client is configured to also receive data, thus turning it into
a server, the client system is acting outside it's operational boundary. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SOCKET_NAME="systemd-journal-remote.socket"
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if "$SYSTEMCTL_EXEC" -q list-unit-files --type socket | grep -q "$SOCKET_NAME"; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop "$SOCKET_NAME"
fi
"$SYSTEMCTL_EXEC" mask "$SOCKET_NAME"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92608-9
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- socket_systemd-journal-remote_disabled
- name: Disable systemd-journal-remote Socket - Collect systemd Socket Units Present
in the System
ansible.builtin.command:
cmd: systemctl -q list-unit-files --type socket
register: result_systemd_unit_files
changed_when: false
check_mode: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92608-9
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- socket_systemd-journal-remote_disabled
- name: Disable systemd-journal-remote Socket - Ensure systemd-journal-remote.socket
is Masked
ansible.builtin.systemd:
name: systemd-journal-remote.socket
state: stopped
enabled: false
masked: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- result_systemd_unit_files.stdout_lines is search("systemd-journal-remote.socket")
tags:
- CCE-92608-9
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- socket_systemd-journal-remote_disabled
|
Configure systemd-journal-upload TLS parameters: ServerKeyFile, ServerCertificateFile and TrustedCertificateFile
[ref]ruleSUSE Linux Enterprise 15 must offload rsyslog messages for networked systems in real time and
offload standalone systems at least weekly Rationale:Information stored in one location is vulnerable to accidental or incidental deletion or alteration.
Offloading is a common process in information systems with limited audit storage capacity |
Configure systemd-journal-upload URL
[ref]ruleSUSE Linux Enterprise 15 must offload rsyslog messages for networked systems in real time and
offload standalone systems at least weekly Rationale:Information stored in one location is vulnerable to accidental or incidental deletion or alteration.
Offloading is a common process in information systems with limited audit storage capacity |
Ensure All Logs are Rotated by logrotate
[ref]groupEdit the file /etc/logrotate.d/syslog. Find the first
line, which should look like this (wrapped for clarity):
/var/log/messages /var/log/secure /var/log/maillog /var/log/spooler \
/var/log/boot.log /var/log/cron {
Edit this line so that it contains a one-space-separated
listing of each log file referenced in /etc/rsyslog.conf.
All logs in use on a system must be rotated regularly, or the
log files will consume disk space over time, eventually interfering
with system operation. The file /etc/logrotate.d/syslog is the
configuration file used by the logrotate program to maintain all
log files written by syslog. By default, it rotates logs weekly and
stores four archival copies of each log. These settings can be
modified by editing /etc/logrotate.conf, but the defaults are
sufficient for purposes of this guide.
Note that logrotate is run nightly by the cron job
/etc/cron.daily/logrotate. If particularly active logs need to be
rotated more often than once a day, some other mechanism must be
used. |
| contains 3 rules |
Ensure logrotate is Installed
[ref]rulelogrotate is installed by default. The logrotate package can be installed with the following command: $ sudo zypper install logrotate Rationale:The logrotate package provides the logrotate services. Identifiers:
CCE-92561-0 References:
1, 14, 15, 16, 3, 5, 6, APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, CM-6(a), PR.PT-1, Req-10.7, 4.2.4, R71, SLES-15-750300285, 10.5.1, 10.5 Remediation script: (show)
[[packages]]
name = "logrotate"
version = "*"
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_logrotate
class install_logrotate {
package { 'logrotate':
ensure => 'installed',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
zypper install -y "logrotate"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92561-0
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- PCI-DSSv4-10.5
- PCI-DSSv4-10.5.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_logrotate_installed
- name: Ensure logrotate is installed
ansible.builtin.package:
name: logrotate
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92561-0
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- PCI-DSSv4-10.5
- PCI-DSSv4-10.5.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_logrotate_installed
|
Ensure Logrotate Runs Periodically
[ref]ruleThe logrotate utility allows for the automatic rotation of
log files. The frequency of rotation is specified in /etc/logrotate.conf,
which triggers a cron task or a timer. To configure logrotate to run daily, add or correct
the following line in /etc/logrotate.conf:
# rotate log files frequency
daily Rationale:Log files that are not properly rotated run the risk of growing so large
that they fill up the /var/log partition. Valuable logging information could be lost
if the /var/log partition becomes full. Identifiers:
CCE-85850-6 References:
1, 14, 15, 16, 3, 5, 6, APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, CM-6(a), PR.PT-1, Req-10.7, 4.2.4, R71, SLES-15-750300285 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q logrotate; }; then
LOGROTATE_CONF_FILE="/etc/logrotate.conf"
SYSTEMCTL_EXEC='/usr/bin/systemctl'
# daily rotation is configured
grep -q "^daily$" $LOGROTATE_CONF_FILE|| sed -i '1i daily' "$LOGROTATE_CONF_FILE"
# remove any line configuring weekly, monthly or yearly rotation
sed -i '/^\s*\(weekly\|monthly\|yearly\).*$/d' $LOGROTATE_CONF_FILE
# enable logrotate timer service
"$SYSTEMCTL_EXEC" unmask 'logrotate.timer'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" start 'logrotate.timer'
fi
"$SYSTEMCTL_EXEC" enable 'logrotate.timer'
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85850-6
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- configure_strategy
- ensure_logrotate_activated
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Configure daily log rotation in /etc/logrotate.conf
ansible.builtin.lineinfile:
create: true
dest: /etc/logrotate.conf
regexp: ^\s*(weekly|monthly|yearly)$
line: daily
state: present
insertbefore: BOF
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"logrotate" in ansible_facts.packages'
tags:
- CCE-85850-6
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- configure_strategy
- ensure_logrotate_activated
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Make sure daily log rotation setting is not overridden in /etc/logrotate.conf
ansible.builtin.lineinfile:
create: false
dest: /etc/logrotate.conf
regexp: ^[\s]*(weekly|monthly|yearly)$
state: absent
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"logrotate" in ansible_facts.packages'
tags:
- CCE-85850-6
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- configure_strategy
- ensure_logrotate_activated
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Enable timer logrotate
ansible.builtin.systemd:
name: logrotate.timer
enabled: 'yes'
state: started
masked: 'no'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"logrotate" in ansible_facts.packages'
tags:
- CCE-85850-6
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- configure_strategy
- ensure_logrotate_activated
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Enable logrotate Timer
[ref]rule
The logrotate timer can be enabled with the following command:
$ sudo systemctl enable logrotate.timer Rationale:Log files that are not properly rotated run the risk of growing so large
that they fill up the /var/log partition. Valuable logging information could be lost
if the /var/log partition becomes full. Identifiers:
CCE-92585-9 References:
1, 14, 15, 16, 3, 5, 6, APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, CM-6(a), PR.PT-1, Req-10.7, 4.2.4, R71, SLES-15-750300285, 10.5.1, 10.5 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q logrotate; }; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" start 'logrotate.timer'
fi
"$SYSTEMCTL_EXEC" enable 'logrotate.timer'
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92585-9
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- PCI-DSSv4-10.5
- PCI-DSSv4-10.5.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- timer_logrotate_enabled
- name: Enable timer logrotate
block:
- name: Gather the package facts
ansible.builtin.package_facts:
manager: auto
- name: Enable timer logrotate
ansible.builtin.systemd:
name: logrotate.timer
enabled: 'yes'
state: started
when:
- '"logrotate" in ansible_facts.packages'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"logrotate" in ansible_facts.packages'
tags:
- CCE-92585-9
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- PCI-DSSv4-10.5
- PCI-DSSv4-10.5.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- timer_logrotate_enabled
|
Configure rsyslogd to Accept Remote Messages If Acting as a Log Server
[ref]groupBy default, rsyslog does not listen over the network
for log messages. If needed, modules can be enabled to allow
the rsyslog daemon to receive messages from other systems and for the system
thus to act as a log server.
If the system is not a log server, then lines concerning these modules
should remain commented out.
|
| contains 1 rule |
Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
[ref]ruleThe rsyslog daemon should not accept remote messages unless the system acts as a log
server. To ensure that it is not listening on the network, ensure any of the following lines
are not found in rsyslog configuration files.
If using legacy syntax:
$ModLoad imtcp
$InputTCPServerRun port
$ModLoad imudp
$UDPServerRun port
$ModLoad imrelp
$InputRELPServerRun port
If using RainerScript syntax:
module(load="imtcp")
module(load="imudp")
input(type="imtcp" port="514")
input(type="imudp" port="514")
Rationale:Any process which receives messages from the network incurs some risk of receiving malicious
messages. This risk can be eliminated for rsyslog by configuring it not to listen on the
network. Identifiers:
CCE-91375-6 References:
1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9, APO01.06, APO11.04, APO13.01, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02, MEA02.01, 4.2.3.4, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.8, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.5.1, A.12.6.2, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.IP-1, PR.PT-1, PR.PT-4, SRG-OS-000480-GPOS-00227, 4.2.1.6, SLES-15-750300195, 0988, 1405 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
legacy_regex='^\s*\$(((Input(TCP|RELP)|UDP)ServerRun)|ModLoad\s+(imtcp|imudp|imrelp))'
rainer_regex='^\s*(module|input)\((load|type)="(imtcp|imudp)".*$'
readarray -t legacy_targets < <(grep -l -E -r "${legacy_regex[@]}" /etc/rsyslog.conf /etc/rsyslog.d/)
readarray -t rainer_targets < <(grep -l -E -r "${rainer_regex[@]}" /etc/rsyslog.conf /etc/rsyslog.d/)
config_changed=false
if [ ${#legacy_targets[@]} -gt 0 ]; then
for target in "${legacy_targets[@]}"; do
sed -E -i "/$legacy_regex/ s/^/# /" "$target"
done
config_changed=true
fi
if [ ${#rainer_targets[@]} -gt 0 ]; then
for target in "${rainer_targets[@]}"; do
sed -E -i "/$rainer_regex/ s/^/# /" "$target"
done
config_changed=true
fi
if $config_changed; then
systemctl restart rsyslog.service
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91375-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_nolisten
- name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
- Define Rsyslog Config Lines Regex in Legacy Syntax
ansible.builtin.set_fact:
rsyslog_listen_legacy_regex: ^\s*\$(((Input(TCP|RELP)|UDP)ServerRun)|ModLoad\s+(imtcp|imudp|imrelp))
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91375-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_nolisten
- name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
- Search for Legacy Config Lines in Rsyslog Main Config File
ansible.builtin.find:
paths: /etc
pattern: rsyslog.conf
contains: '{{ rsyslog_listen_legacy_regex }}'
register: rsyslog_listen_legacy_main_file
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91375-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_nolisten
- name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
- Search for Legacy Config Lines in Rsyslog Include Files
ansible.builtin.find:
paths: /etc/rsyslog.d/
pattern: '*.conf'
contains: '{{ rsyslog_listen_legacy_regex }}'
register: rsyslog_listen_legacy_include_files
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91375-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_nolisten
- name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
- Assemble List of Config Files With Listen Lines in Legacy Syntax
ansible.builtin.set_fact:
rsyslog_legacy_remote_listen_files: '{{ rsyslog_listen_legacy_main_file.files
| map(attribute=''path'') | list + rsyslog_listen_legacy_include_files.files
| map(attribute=''path'') | list }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91375-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_nolisten
- name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
- Comment Listen Config Lines Wherever Defined Using Legacy Syntax
ansible.builtin.replace:
path: '{{ item }}'
regexp: '{{ rsyslog_listen_legacy_regex }}'
replace: '# \1'
loop: '{{ rsyslog_legacy_remote_listen_files }}'
register: rsyslog_listen_legacy_comment
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_legacy_remote_listen_files | length > 0
tags:
- CCE-91375-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_nolisten
- name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
- Define Rsyslog Config Lines Regex in RainerScript Syntax
ansible.builtin.set_fact:
rsyslog_listen_rainer_regex: ^\s*(module|input)\((load|type)="(imtcp|imudp)".*$
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91375-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_nolisten
- name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
- Search for RainerScript Config Lines in Rsyslog Main Config File
ansible.builtin.find:
paths: /etc
pattern: rsyslog.conf
contains: '{{ rsyslog_listen_rainer_regex }}'
register: rsyslog_rainer_remote_main_file
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91375-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_nolisten
- name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
- Search for RainerScript Config Lines in Rsyslog Include Files
ansible.builtin.find:
paths: /etc/rsyslog.d/
pattern: '*.conf'
contains: '{{ rsyslog_listen_rainer_regex }}'
register: rsyslog_rainer_remote_include_files
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91375-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_nolisten
- name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
- Assemble List of Config Files With Listen Lines in RainerScript
ansible.builtin.set_fact:
rsyslog_rainer_remote_listen_files: '{{ rsyslog_rainer_remote_main_file.files
| map(attribute=''path'') | list + rsyslog_rainer_remote_include_files.files
| map(attribute=''path'') | list }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91375-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_nolisten
- name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
- Comment Listen Config Lines Wherever Defined Using RainerScript
ansible.builtin.replace:
path: '{{ item }}'
regexp: '{{ rsyslog_listen_rainer_regex }}'
replace: '# \1'
loop: '{{ rsyslog_rainer_remote_listen_files }}'
register: rsyslog_listen_rainer_comment
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_rainer_remote_listen_files | length > 0
tags:
- CCE-91375-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_nolisten
- name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
- Restart Rsyslog if Any Line Were Commented Out
ansible.builtin.service:
name: rsyslog
state: restarted
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_listen_legacy_comment is changed or rsyslog_listen_rainer_comment is changed
tags:
- CCE-91375-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_nolisten
|
Rsyslog Logs Sent To Remote Host
[ref]groupIf system logs are to be useful in detecting malicious
activities, it is necessary to send logs to a remote server. An
intruder who has compromised the root account on a system may
delete the log entries which indicate that the system was attacked
before they are seen by an administrator.
However, it is recommended that logs be stored on the local
host in addition to being sent to the loghost, especially if
rsyslog has been configured to use the UDP protocol to send
messages over a network. UDP does not guarantee reliable delivery,
and moderately busy sites will lose log messages occasionally,
especially in periods of high traffic which may be the result of an
attack. In addition, remote rsyslog messages are not
authenticated in any way by default, so it is easy for an attacker to
introduce spurious messages to the central log server. Also, some
problems cause loss of network connectivity, which will prevent the
sending of messages to the central server. For all of these reasons, it is
better to store log messages both centrally and on each host, so
that they can be correlated if necessary. |
| contains 1 rule |
Ensure Logs Sent To Remote Host
[ref]ruleTo configure rsyslog to send logs to a remote log server,
open /etc/rsyslog.conf and read and understand the last section of the file,
which describes the multiple directives necessary to activate remote
logging.
Along with these other directives, the system can be configured
to forward its logs to a particular log server by
adding or correcting one of the following lines,
substituting logcollector appropriately.
The choice of protocol depends on the environment of the system;
although TCP and RELP provide more reliable message delivery,
they may not be supported in all environments.
To use UDP for log message delivery:
*.* @logcollector
Or in RainerScript:
*.* action(type="omfwd" ... target="logcollector" protocol="udp")
To use TCP for log message delivery:
*.* @@logcollector
Or in RainerScript:
*.* action(type="omfwd" ... target="logcollector" protocol="tcp")
To use RELP for log message delivery:
*.* :omrelp:logcollector
Or in RainerScript:
*.* action(type="omfwd" ... target="logcollector" protocol="relp")
There must be a resolvable DNS CNAME or Alias record set to "logcollector" for logs to be sent correctly to the centralized logging utility.Warning:
It is important to configure queues in case the client is sending log
messages to a remote server. If queues are not configured,
the system will stop functioning when the connection
to the remote server is not available. Please consult Rsyslog
documentation for more information about configuration of queues. The
example configuration which should go into /etc/rsyslog.conf
can look like the following lines:
$ActionQueueType LinkedList
$ActionQueueFileName queuefilename
$ActionQueueMaxDiskSpace 1g
$ActionQueueSaveOnShutdown on
$ActionResumeRetryCount -1
Or if using Rainer Script syntax, it could be:
*.* action(type="omfwd" queue.type="linkedlist" queue.filename="example_fwd" action.resumeRetryCount="-1" queue.saveOnShutdown="on" target="example.com" port="30514" protocol="tcp") Rationale:A log server (loghost) receives syslog messages from one or more
systems. This data can be used as an additional log source in the event a
system is compromised and its local logs are suspect. Forwarding log messages
to a remote loghost also provides system administrators with a centralized
place to view the status of multiple hosts within the enterprise. Identifiers:
CCE-85552-8 References:
1, 13, 14, 15, 16, 2, 3, 5, 6, APO11.04, APO13.01, BAI03.05, BAI04.04, DSS05.04, DSS05.07, MEA02.01, 164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(B), 164.308(a)(5)(ii)(C), 164.308(a)(6)(ii), 164.308(a)(8), 164.310(d)(2)(iii), 164.312(b), 164.314(a)(2)(i)(C), 164.314(a)(2)(iii), 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 7.1, SR 7.2, A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.17.2.1, CIP-003-8 R5.2, CIP-004-6 R3.3, CM-6(a), AU-4(1), AU-9(2), PR.DS-4, PR.PT-1, SRG-OS-000479-GPOS-00224, SRG-OS-000480-GPOS-00227, SRG-OS-000342-GPOS-00133, SLES-15-010580, 4.2.1.5, R71, SLES-15-750300180, 0988, 1405, SV-234865r1082187_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
rsyslog_remote_loghost_address='logcollector'
# If the key exists, comment it. Otherwise do nothing
# We search for the key string followed by a blank space,
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^\*\.\*[[:blank:]]" "/etc/rsyslog.conf"; then
LC_ALL=C sed -i --follow-symlinks "s/^\*\.\*[[:blank:]].*/#&/gi" "/etc/rsyslog.conf"
fi
# If the key exists, comment it. Otherwise do nothing
# We search for the key string followed by a blank space,
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^\*\.\*[[:blank:]]" "/etc/rsyslog.d/*.conf"; then
LC_ALL=C sed -i --follow-symlinks "s/^\*\.\*[[:blank:]].*/#&/gi" "/etc/rsyslog.d/*.conf"
fi
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^\*\.\*")
# shellcheck disable=SC2059
printf -v formatted_output "%s %s" "$stripped_key" "@@$rsyslog_remote_loghost_address"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^\*\.\*\\>" "/etc/rsyslog.d/remote.conf"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^\*\.\*\\>.*/$escaped_formatted_output/gi" "/etc/rsyslog.d/remote.conf"
else
if [[ -s "/etc/rsyslog.d/remote.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/rsyslog.d/remote.conf" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/rsyslog.d/remote.conf"
fi
cce="CCE-85552-8"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/rsyslog.d/remote.conf" >> "/etc/rsyslog.d/remote.conf"
printf '%s\n' "$formatted_output" >> "/etc/rsyslog.d/remote.conf"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85552-8
- DISA-STIG-SLES-15-010580
- NIST-800-53-AU-4(1)
- NIST-800-53-AU-9(2)
- NIST-800-53-CM-6(a)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- rsyslog_remote_loghost
- name: XCCDF Value rsyslog_remote_loghost_address # promote to variable
set_fact:
rsyslog_remote_loghost_address: !!str logcollector
tags:
- always
- name: Check for duplicate values in master configuration
ansible.builtin.lineinfile:
path: /etc/rsyslog.conf
create: false
regexp: ^\*\.\*\s+.*$
state: absent
changed_when: false
register: dupes_master
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85552-8
- DISA-STIG-SLES-15-010580
- NIST-800-53-AU-4(1)
- NIST-800-53-AU-9(2)
- NIST-800-53-CM-6(a)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- rsyslog_remote_loghost
- name: Collect all config rsyslog files which configure remote logger
ansible.builtin.find:
paths: /etc/rsyslog.d/
contains: ^\*\.\*\s+.*$
patterns: '*.conf'
register: rsyslog_dropin_config_files
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85552-8
- DISA-STIG-SLES-15-010580
- NIST-800-53-AU-4(1)
- NIST-800-53-AU-9(2)
- NIST-800-53-CM-6(a)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- rsyslog_remote_loghost
- name: Deduplicate values from rsyslog dropin configuration
ansible.builtin.lineinfile:
path: '{{ item.path }}'
create: false
regexp: ^\*\.\*\s+.*$
state: absent
loop: '{{ rsyslog_dropin_config_files.files }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85552-8
- DISA-STIG-SLES-15-010580
- NIST-800-53-AU-4(1)
- NIST-800-53-AU-9(2)
- NIST-800-53-CM-6(a)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- rsyslog_remote_loghost
- name: Set rsyslog remote loghost
ansible.builtin.lineinfile:
dest: /etc/rsyslog.d/remote.conf
regexp: ^\*\.\*\s+.*$
line: '*.* @@{{ rsyslog_remote_loghost_address }}'
create: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85552-8
- DISA-STIG-SLES-15-010580
- NIST-800-53-AU-4(1)
- NIST-800-53-AU-9(2)
- NIST-800-53-CM-6(a)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- rsyslog_remote_loghost
|
Ensure rsyslog is Installed
[ref]ruleRsyslog is installed by default. The rsyslog package can be installed with the following command: $ sudo zypper install rsyslog Rationale:The rsyslog package provides the rsyslog daemon, which provides
system logging services. Identifiers:
CCE-91161-0 References:
1, 14, 15, 16, 3, 5, 6, APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01, 164.312(a)(2)(ii), 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, CM-6(a), PR.PT-1, SRG-OS-000479-GPOS-00224, SRG-OS-000051-GPOS-00024, SRG-OS-000480-GPOS-00227, 4.2.1.1, SLES-15-750300210, 1409 Remediation script: (show)
[[packages]]
name = "rsyslog"
version = "*"
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_rsyslog
class install_rsyslog {
package { 'rsyslog':
ensure => 'installed',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
zypper install -y "rsyslog"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91161-0
- NIST-800-53-CM-6(a)
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_rsyslog_installed
- name: Ensure rsyslog is installed
ansible.builtin.package:
name: rsyslog
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91161-0
- NIST-800-53-CM-6(a)
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_rsyslog_installed
|
Enable rsyslog Service
[ref]ruleThe rsyslog service provides syslog-style logging by default on SUSE Linux Enterprise 15.
The rsyslog service can be enabled with the following command:
$ sudo systemctl enable rsyslog.service Rationale:The rsyslog service must be running in order to provide
logging services, which are essential to system administration. Identifiers:
CCE-91162-8 References:
1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO13.01, BAI03.05, BAI04.04, DSS01.03, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 164.312(a)(2)(ii), 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, SR 7.1, SR 7.2, A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.14.2.7, A.15.2.1, A.15.2.2, A.17.2.1, CM-6(a), AU-4(1), DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.DS-4, PR.PT-1, SRG-OS-000480-GPOS-00227, 4.2.1.2, SLES-15-750300225, 1409 Remediation script: (show)
[customizations.services]
enabled = ["rsyslog"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include enable_rsyslog
class enable_rsyslog {
service {'rsyslog':
enable => true,
ensure => 'running',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" unmask 'rsyslog.service'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" start 'rsyslog.service'
fi
"$SYSTEMCTL_EXEC" enable 'rsyslog.service'
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91162-8
- NIST-800-53-AU-4(1)
- NIST-800-53-CM-6(a)
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_rsyslog_enabled
- name: Enable rsyslog Service - Enable service rsyslog
block:
- name: Gather the package facts
ansible.builtin.package_facts:
manager: auto
- name: Enable rsyslog Service - Enable Service rsyslog
ansible.builtin.systemd:
name: rsyslog
enabled: true
state: started
masked: false
when:
- '"rsyslog" in ansible_facts.packages'
tags:
- CCE-91162-8
- NIST-800-53-AU-4(1)
- NIST-800-53-CM-6(a)
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_rsyslog_enabled
- special_service_block
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
Ensure One Logging Service Is In Use
[ref]ruleEnsure that a logging system is active and in use.
systemctl is-active rsyslog systemd-journald
The command should return at least one active.Warning:
This rule does not come with a remediation. There are specific rules
for enabling each logging service which should be enabled instead. Rationale:The system should have one active logging service to avoid conflicts
and ensure consistency. |
Ensure rsyslog Default File Permissions Configured
[ref]rulersyslog will create logfiles that do not already exist on the system.
This settings controls what permissions will be applied to these newly
created files. Rationale:It is important to ensure that log files have the correct permissions
to ensure that sensitive data is archived and protected. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
sed -i '/^\s*$FileCreateMode/d' /etc/rsyslog.d/*
if ! grep -qE '^\s*\$FileCreateMode\s+0640' /etc/rsyslog.conf; then
if grep -qE '^\s*\$FileCreateMode' /etc/rsyslog.conf; then
sed -i '/^\s*\$FileCreateMode/ s/^/#/' /etc/rsyslog.conf
fi
## Assume there is no filter named as 00-, otherwise those filters might be included before this configuration and create file with different permissions
echo '$FileCreateMode 0640' > /etc/rsyslog.d/00-rsyslog_filecreatemode.conf
fi
systemctl restart rsyslog.service
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92599-0
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_filecreatemode
- name: Ensure rsyslog Default File Permissions Configured - Search for $FileCreateMode
Parameter in rsyslog Main Config File
ansible.builtin.find:
paths: /etc
pattern: rsyslog.conf
contains: ^\s*\$FileCreateMode\s*\d+
register: rsyslog_main_file_with_filecreatemode
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92599-0
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_filecreatemode
- name: Ensure rsyslog Default File Permissions Configured - Search for $FileCreateMode
Parameter in rsyslog Include Files
ansible.builtin.find:
paths: /etc/rsyslog.d/
pattern: '*.conf'
contains: ^\s*\$FileCreateMode\s*\d+
register: rsyslog_includes_with_filecreatemode
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92599-0
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_filecreatemode
- name: Ensure rsyslog Default File Permissions Configured - Assemble List of rsyslog
Configuration Files with $FileCreateMode Parameter
ansible.builtin.set_fact:
rsyslog_filecreatemode_files: '{{ rsyslog_main_file_with_filecreatemode.files
| map(attribute=''path'') | list + rsyslog_includes_with_filecreatemode.files
| map(attribute=''path'') | list }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92599-0
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_filecreatemode
- name: Ensure rsyslog Default File Permissions Configured - Remove $FileCreateMode
Parameter from Multiple Files to Avoid Conflicts
ansible.builtin.lineinfile:
path: '{{ item }}'
regexp: \$FileCreateMode.*
state: absent
register: result_rsyslog_filecreatemode_removed
loop: '{{ rsyslog_filecreatemode_files }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_filecreatemode_files | length > 1
tags:
- CCE-92599-0
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_filecreatemode
- name: Ensure rsyslog Default File Permissions Configured - Add $FileCreateMode Parameter
and Expected Value
ansible.builtin.lineinfile:
path: /etc/rsyslog.d/00-rsyslog_filecreatemode.conf
line: $FileCreateMode 0640
mode: 416
create: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_filecreatemode_files | length == 0 or result_rsyslog_filecreatemode_removed
is not skipped
tags:
- CCE-92599-0
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_filecreatemode
- name: Ensure rsyslog Default File Permissions Configured - Ensure Correct Value
of Existing $FileCreateMode Parameter
ansible.builtin.lineinfile:
path: '{{ item }}'
regexp: ^\$FileCreateMode
line: $FileCreateMode 0640
loop: '{{ rsyslog_filecreatemode_files }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- rsyslog_filecreatemode_files | length == 1
tags:
- CCE-92599-0
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- rsyslog_filecreatemode
|
Network Configuration and Firewalls
[ref]groupMost systems must be connected to a network of some
sort, and this brings with it the substantial risk of network
attack. This section discusses the security impact of decisions
about networking which must be made when configuring a system.
This section also discusses firewalls, network access
controls, and other network security frameworks, which allow
system-level rules to be written that can limit an attackers' ability
to connect to your system. These rules can specify that network
traffic should be allowed or denied from certain IP addresses,
hosts, and networks. The rules can also specify which of the
system's network services are available to particular hosts or
networks. |
| contains 41 rules |
firewalld
[ref]groupThe dynamic firewall daemon firewalld provides a
dynamically managed firewall with support for network “zones” to assign
a level of trust to a network and its associated connections and interfaces.
It has support for IPv4 and IPv6 firewall settings. It supports Ethernet
bridges and has a separation of runtime and permanent configuration options.
It also has an interface for services or applications to add firewall rules
directly.
A graphical configuration tool, firewall-config, is used to configure
firewalld, which in turn uses iptables tool to communicate
with Netfilter in the kernel which implements packet filtering.
The firewall service provided by firewalld is dynamic rather than
static because changes to the configuration can be made at anytime and are
immediately implemented. There is no need to save or apply the changes. No
unintended disruption of existing network connections occurs as no part of
the firewall has to be reloaded. |
| contains 3 rules |
Inspect and Activate Default firewalld Rules
[ref]groupFirewalls can be used to separate networks into different zones
based on the level of trust the user has decided to place on the devices and
traffic within that network. NetworkManager informs firewalld to which
zone an interface belongs. An interface's assigned zone can be changed by
NetworkManager or via the firewall-config tool.
The zone settings in /etc/firewalld/ are a range of preset settings
which can be quickly applied to a network interface. These are the zones
provided by firewalld sorted according to the default trust level of the
zones from untrusted to trusted:
drop
Any incoming network packets are dropped, there is no
reply. Only outgoing network connections are possible. block
Any incoming network connections are rejected with an
icmp-host-prohibited message for IPv4 and icmp6-adm-prohibited
for IPv6. Only network connections initiated from within the system are
possible. public
For use in public areas. You do not trust the other
computers on the network to not harm your computer. Only selected incoming
connections are accepted. external
For use on external networks with masquerading enabled
especially for routers. You do not trust the other computers on the network to
not harm your computer. Only selected incoming connections are accepted. dmz
For computers in your demilitarized zone that are
publicly-accessible with limited access to your internal network. Only selected
incoming connections are accepted. work
For use in work areas. You mostly trust the other computers
on networks to not harm your computer. Only selected incoming connections are
accepted. home
For use in home areas. You mostly trust the other computers
on networks to not harm your computer. Only selected incoming connections are
accepted. internal
For use on internal networks. You mostly trust the
other computers on the networks to not harm your computer. Only selected
incoming connections are accepted. trusted
All network connections are accepted.
It is possible to designate one of these zones to be the default zone. When
interface connections are added to NetworkManager, they are assigned
to the default zone. On installation, the default zone in firewalld is set to
be the public zone.
To find out all the settings of a zone, for example the public zone,
enter the following command as root:
# firewall-cmd --zone=public --list-all
Example output of this command might look like the following:
# firewall-cmd --zone=public --list-all
public
interfaces:
services: mdns dhcpv6-client ssh
ports:
forward-ports:
icmp-blocks: source-quench
To view the network zones currently active, enter the following command as root:
# firewall-cmd --get-service
The following listing displays the result of this command
on common SUSE Linux Enterprise 15 system:
# firewall-cmd --get-service
amanda-client bacula bacula-client dhcp dhcpv6 dhcpv6-client dns ftp
high-availability http https imaps ipp ipp-client ipsec kerberos kpasswd
ldap ldaps libvirt libvirt-tls mdns mountd ms-wbt mysql nfs ntp openvpn
pmcd pmproxy pmwebapi pmwebapis pop3s postgresql proxy-dhcp radius rpc-bind
samba samba-client smtp ssh telnet tftp tftp-client transmission-client
vnc-server wbem-https
Finally to view the network zones that will be active after the next firewalld
service reload, enter the following command as root:
# firewall-cmd --get-service --permanent |
| contains 2 rules |
Install firewalld Package
[ref]ruleThe firewalld package can be installed with the following command:
$ sudo zypper install firewalld Rationale:"Firewalld" provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols.
Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best.
Remote access is access to nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless.
SUSE Linux Enterprise 15 functionality (e.g., SSH) must be capable of taking enforcement action if the audit reveals unauthorized activity.
Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets)." Identifiers:
CCE-85698-9 References:
CM-7, CM-7.1(iii), CM-7(b), AC-17(1), FMT_SMF_EXT.1, SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115, SRG-OS-000298-GPOS-00116, SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00232, SLES-15-010220, 3.5.1.1, SLES-15-450600030, 1409, 1.2.1, 1.2, SV-234821r958480_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_network_filtering_service='firewalld'
if [ $var_network_filtering_service == firewalld ]; then
zypper install -y "firewalld"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85698-9
- DISA-STIG-SLES-15-010220
- NIST-800-53-AC-17(1)
- NIST-800-53-CM-7
- NIST-800-53-CM-7(b)
- NIST-800-53-CM-7.1(iii)
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_firewalld_installed
- name: XCCDF Value var_network_filtering_service # promote to variable
set_fact:
var_network_filtering_service: !!str firewalld
tags:
- always
- name: Ensure firewalld is installed
ansible.builtin.package:
name: firewalld
state: present
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- var_network_filtering_service == "firewalld"
tags:
- CCE-85698-9
- DISA-STIG-SLES-15-010220
- NIST-800-53-AC-17(1)
- NIST-800-53-CM-7
- NIST-800-53-CM-7(b)
- NIST-800-53-CM-7.1(iii)
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_firewalld_installed
|
Verify firewalld Enabled
[ref]rule
The firewalld service can be enabled with the following command:
$ sudo systemctl enable firewalld.service Rationale:Access control methods provide the ability to enhance system security posture
by restricting services and known good IP addresses and address ranges. This
prevents connections from unknown hosts and protocols. Identifiers:
CCE-85751-6 References:
11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.3, 3.4.7, 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, CIP-003-8 R4, CIP-003-8 R5, CIP-004-6 R3, CM-7, CM-7.1(iii), CM-7(b), AC-17(1), PR.IP-1, FMT_SMF_EXT.1, SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115, SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00231, SRG-OS-000480-GPOS-00232, SLES-15-010220, 3.5.1.3, SYS.1.6.A5, SYS.1.6.A21, SLES-15-450600090, 1409, 1.2.1, 1.2, SV-234821r958480_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q firewalld; }; then
var_network_filtering_service='firewalld'
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [ $var_network_filtering_service == firewalld ]; then
"$SYSTEMCTL_EXEC" unmask 'firewalld.service'
"$SYSTEMCTL_EXEC" start 'firewalld.service'
"$SYSTEMCTL_EXEC" enable 'firewalld.service'
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85751-6
- DISA-STIG-SLES-15-010220
- NIST-800-171-3.1.3
- NIST-800-171-3.4.7
- NIST-800-53-AC-17(1)
- NIST-800-53-CM-7
- NIST-800-53-CM-7(b)
- NIST-800-53-CM-7.1(iii)
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_firewalld_enabled
- name: XCCDF Value var_network_filtering_service # promote to variable
set_fact:
var_network_filtering_service: !!str firewalld
tags:
- always
- name: Enable service firewalld
block:
- name: Gather the package facts
ansible.builtin.package_facts:
manager: auto
- name: Enable service firewalld
ansible.builtin.systemd:
name: firewalld
enabled: 'yes'
state: started
masked: 'no'
when:
- '"firewalld" in ansible_facts.packages'
- var_network_filtering_service == "firewalld"
- var_network_filtering_service == "firewalld"
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"firewalld" in ansible_facts.packages'
tags:
- CCE-85751-6
- DISA-STIG-SLES-15-010220
- NIST-800-171-3.1.3
- NIST-800-171-3.4.7
- NIST-800-53-AC-17(1)
- NIST-800-53-CM-7
- NIST-800-53-CM-7(b)
- NIST-800-53-CM-7.1(iii)
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_firewalld_enabled
|
Strengthen the Default Ruleset
[ref]groupThe default rules can be strengthened. The system
scripts that activate the firewall rules expect them to be defined
in configuration files under the /etc/firewalld/services
and /etc/firewalld/zones directories.
The following recommendations describe how to strengthen the
default ruleset configuration file. An alternative to editing this
configuration file is to create a shell script that makes calls to
the firewall-cmd program to load in rules under the /etc/firewalld/services
and /etc/firewalld/zones directories.
Instructions apply to both unless otherwise noted. Language and address
conventions for regular firewalld rules are used throughout this section. Warning:
The program firewall-config
allows additional services to penetrate the default firewall rules
and automatically adjusts the firewalld ruleset(s). |
| contains 1 rule |
Set Default firewalld Zone for Incoming Packets
[ref]ruleTo set the default zone to drop for
the built-in default zone which processes incoming IPv4 and IPv6 packets,
modify the following line in
/etc/firewalld/firewalld.conf to be:
DefaultZone=drop Warning:
To prevent denying any access to the system, automatic remediation
of this control is not available. Remediation must be automated as
a component of machine provisioning, or followed manually as outlined
above. Rationale:In firewalld the default zone is applied only after all
the applicable rules in the table are examined for a match. Setting the
default zone to drop implements proper design for a firewall, i.e.
any packets which are not explicitly permitted should not be
accepted. Identifiers:
CCE-91410-1 References:
11, 14, 3, 9, 5.10.1, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.3, 3.4.7, 3.13.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CA-3(5), CM-7(b), SC-7(23), CM-6(a), PR.IP-1, PR.PT-3, Req-1.4, SRG-OS-000480-GPOS-00227, 3.5.1.4, SLES-15-450600075, 1416, 1.3.1, 1.3 |
IPSec Support
[ref]groupSupport for Internet Protocol Security (IPsec)
is provided with Libreswan. |
| contains 5 rules |
Verify Group Who Owns /etc/ipsec.d Directory
[ref]rule To properly set the group owner of /etc/ipsec.d, run the command:
$ sudo chgrp root /etc/ipsec.d
Rationale:The ownership of the /etc/ipsec.d directory by the root group is important
because this directory hosts Libreswan configuration. Protection of this
file is critical for system security. Assigning the ownership to root
ensures exclusive control of the Libreswan configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q strongswan-ipsec; then
newgroup=""
if getent group "root" >/dev/null 2>&1; then
newgroup="root"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "root is not a defined group on the system"
else
find -P /etc/ipsec.d/ -maxdepth 0 -type d ! -group root -exec chgrp --no-dereference "$newgroup" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92499-3
- configure_strategy
- directory_groupowner_etc_ipsecd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Check that the root group is defined
ansible.builtin.getent:
database: group
key: root
ignore_errors: true
when:
- '"strongswan-ipsec" in ansible_facts.packages'
- directory_groupowner_etc_ipsecd_newgroup is undefined
tags:
- CCE-92499-3
- configure_strategy
- directory_groupowner_etc_ipsecd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the directory_groupowner_etc_ipsecd_newgroup variable if root found
ansible.builtin.set_fact:
directory_groupowner_etc_ipsecd_newgroup: root
when:
- '"strongswan-ipsec" in ansible_facts.packages'
- ansible_facts.getent_group["root"] is defined
tags:
- CCE-92499-3
- configure_strategy
- directory_groupowner_etc_ipsecd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/ipsec.d/
ansible.builtin.file:
path: /etc/ipsec.d/
follow: false
state: directory
group: '{{ directory_groupowner_etc_ipsecd_newgroup }}'
when: '"strongswan-ipsec" in ansible_facts.packages'
tags:
- CCE-92499-3
- configure_strategy
- directory_groupowner_etc_ipsecd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns /etc/ipsec.d Directory
[ref]rule To properly set the owner of /etc/ipsec.d, run the command:
$ sudo chown root /etc/ipsec.d
Rationale:The ownership of the /etc/ipsec.d directory by the root user is important
because this directory hosts Libreswan configuration. Protection of this
file is critical for system security. Assigning the ownership to root
ensures exclusive control of the Libreswan configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q strongswan-ipsec; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
find -P /etc/ipsec.d/ -maxdepth 0 -type d ! -user 0 -exec chown --no-dereference "$newown" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92508-1
- configure_strategy
- directory_owner_etc_ipsecd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the directory_owner_etc_ipsecd_newown variable if represented by uid
ansible.builtin.set_fact:
directory_owner_etc_ipsecd_newown: '0'
when: '"strongswan-ipsec" in ansible_facts.packages'
tags:
- CCE-92508-1
- configure_strategy
- directory_owner_etc_ipsecd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on directory /etc/ipsec.d/
ansible.builtin.file:
path: /etc/ipsec.d/
follow: false
state: directory
owner: '{{ directory_owner_etc_ipsecd_newown }}'
when: '"strongswan-ipsec" in ansible_facts.packages'
tags:
- CCE-92508-1
- configure_strategy
- directory_owner_etc_ipsecd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions On /etc/ipsec.d Directory
[ref]rule To properly set the permissions of /etc/ipsec.d, run the command: $ sudo chmod 0700 /etc/ipsec.d Rationale:Setting correct permissions on the /etc/ipsec.d directory is important
because this directory hosts Libreswan configuration. Protection of this
directory is critical for system security. Restricting the permissions
ensures exclusive control of the Libreswan configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q strongswan-ipsec; then
find -H /etc/ipsec.d/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92517-2
- configure_strategy
- directory_permissions_etc_ipsecd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/ipsec.d/ file(s)
ansible.builtin.command: 'find -P /etc/ipsec.d/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type
d '
register: files_found
changed_when: false
failed_when: false
check_mode: false
when: '"strongswan-ipsec" in ansible_facts.packages'
tags:
- CCE-92517-2
- configure_strategy
- directory_permissions_etc_ipsecd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set permissions for /etc/ipsec.d/ file(s)
ansible.builtin.file:
path: '{{ item }}'
mode: u-s,g-xwrs,o-xwrt
state: directory
with_items:
- '{{ files_found.stdout_lines }}'
when: '"strongswan-ipsec" in ansible_facts.packages'
tags:
- CCE-92517-2
- configure_strategy
- directory_permissions_etc_ipsecd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns /etc/ipsec.conf File
[ref]rule To properly set the group owner of /etc/ipsec.conf, run the command:
$ sudo chgrp root /etc/ipsec.conf
Rationale:The ownership of the /etc/ipsec.conf file by the root group is important
because this file hosts Libreswan configuration. Protection of this
file is critical for system security. Assigning the ownership to root
ensures exclusive control of the Libreswan configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q strongswan-ipsec; then
newgroup=""
if getent group "root" >/dev/null 2>&1; then
newgroup="root"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "root is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/ipsec.conf" | grep -E -w -q "root"; then
chgrp --no-dereference "$newgroup" /etc/ipsec.conf
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92535-4
- configure_strategy
- file_groupowner_etc_ipsec_conf
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Check that the root group is defined
ansible.builtin.getent:
database: group
key: root
ignore_errors: true
when:
- '"strongswan-ipsec" in ansible_facts.packages'
- file_groupowner_etc_ipsec_conf_newgroup is undefined
tags:
- CCE-92535-4
- configure_strategy
- file_groupowner_etc_ipsec_conf
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_groupowner_etc_ipsec_conf_newgroup variable if root found
ansible.builtin.set_fact:
file_groupowner_etc_ipsec_conf_newgroup: root
when:
- '"strongswan-ipsec" in ansible_facts.packages'
- ansible_facts.getent_group["root"] is defined
tags:
- CCE-92535-4
- configure_strategy
- file_groupowner_etc_ipsec_conf
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/ipsec.conf
ansible.builtin.stat:
path: /etc/ipsec.conf
register: file_exists
when: '"strongswan-ipsec" in ansible_facts.packages'
tags:
- CCE-92535-4
- configure_strategy
- file_groupowner_etc_ipsec_conf
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/ipsec.conf
ansible.builtin.file:
path: /etc/ipsec.conf
follow: false
group: '{{ file_groupowner_etc_ipsec_conf_newgroup }}'
when:
- '"strongswan-ipsec" in ansible_facts.packages'
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92535-4
- configure_strategy
- file_groupowner_etc_ipsec_conf
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns /etc/ipsec.secrets File
[ref]rule To properly set the group owner of /etc/ipsec.secrets, run the command:
$ sudo chgrp root /etc/ipsec.secrets
Rationale:The ownership of the /etc/ipsec.secrets file by the root group is important
because this file hosts Libreswan configuration. Protection of this
file is critical for system security. Assigning the ownership to root
ensures exclusive control of the Libreswan configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q strongswan-ipsec; then
newgroup=""
if getent group "root" >/dev/null 2>&1; then
newgroup="root"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "root is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/ipsec.secrets" | grep -E -w -q "root"; then
chgrp --no-dereference "$newgroup" /etc/ipsec.secrets
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92537-0
- configure_strategy
- file_groupowner_etc_ipsec_secrets
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Check that the root group is defined
ansible.builtin.getent:
database: group
key: root
ignore_errors: true
when:
- '"strongswan-ipsec" in ansible_facts.packages'
- file_groupowner_etc_ipsec_secrets_newgroup is undefined
tags:
- CCE-92537-0
- configure_strategy
- file_groupowner_etc_ipsec_secrets
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_groupowner_etc_ipsec_secrets_newgroup variable if root found
ansible.builtin.set_fact:
file_groupowner_etc_ipsec_secrets_newgroup: root
when:
- '"strongswan-ipsec" in ansible_facts.packages'
- ansible_facts.getent_group["root"] is defined
tags:
- CCE-92537-0
- configure_strategy
- file_groupowner_etc_ipsec_secrets
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/ipsec.secrets
ansible.builtin.stat:
path: /etc/ipsec.secrets
register: file_exists
when: '"strongswan-ipsec" in ansible_facts.packages'
tags:
- CCE-92537-0
- configure_strategy
- file_groupowner_etc_ipsec_secrets
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/ipsec.secrets
ansible.builtin.file:
path: /etc/ipsec.secrets
follow: false
group: '{{ file_groupowner_etc_ipsec_secrets_newgroup }}'
when:
- '"strongswan-ipsec" in ansible_facts.packages'
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92537-0
- configure_strategy
- file_groupowner_etc_ipsec_secrets
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
The system includes support for Internet Protocol
version 6. A major and often-mentioned improvement over IPv4 is its
enormous increase in the number of available addresses. Another
important feature is its support for automatic configuration of
many network settings. |
| contains 7 rules |
Configure IPv6 Settings if Necessary
[ref]groupA major feature of IPv6 is the extent to which systems
implementing it can automatically configure their networking
devices using information from the network. From a security
perspective, manually configuring important configuration
information is preferable to accepting it from the network
in an unauthenticated fashion. |
| contains 7 rules |
Configure Accepting Router Advertisements on All IPv6 Interfaces
[ref]ruleTo set the runtime status of the net.ipv6.conf.all.accept_ra kernel parameter, run the following command: $ sudo sysctl -w net.ipv6.conf.all.accept_ra=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv6.conf.all.accept_ra = 0 Rationale:An illicit router advertisement message could result in a man-in-the-middle attack. Identifiers:
CCE-92473-8 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, 3.3.9, SLES-15-450450165 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv6.conf.all.accept_ra from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.accept_ra.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv6.conf.all.accept_ra" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv6_conf_all_accept_ra.conf'
sysctl_net_ipv6_conf_all_accept_ra_value='0'
#
# Set runtime for net.ipv6.conf.all.accept_ra
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv6.conf.all.accept_ra="$sysctl_net_ipv6_conf_all_accept_ra_value"
fi
#
# If net.ipv6.conf.all.accept_ra present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv6.conf.all.accept_ra = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.accept_ra")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_accept_ra_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.accept_ra\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.accept_ra\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-92473-8"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92473-8
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_ra
- name: XCCDF Value sysctl_net_ipv6_conf_all_accept_ra_value # promote to variable
set_fact:
sysctl_net_ipv6_conf_all_accept_ra_value: !!str 0
tags:
- always
- name: Configure Accepting Router Advertisements on All IPv6 Interfaces - Set fact
for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92473-8
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_ra
- name: Configure Accepting Router Advertisements on All IPv6 Interfaces - Find all
files that contain net.ipv6.conf.all.accept_ra
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.all.accept_ra\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92473-8
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_ra
- name: Configure Accepting Router Advertisements on All IPv6 Interfaces - Find all
files that set net.ipv6.conf.all.accept_ra to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.all.accept_ra\s*=\s*{{ sysctl_net_ipv6_conf_all_accept_ra_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92473-8
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_ra
- name: Configure Accepting Router Advertisements on All IPv6 Interfaces - Comment
out any occurrences of net.ipv6.conf.all.accept_ra from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv6.conf.all.accept_ra
replace: '#net.ipv6.conf.all.accept_ra'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-92473-8
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_ra
- name: Configure Accepting Router Advertisements on All IPv6 Interfaces - Comment
out any occurrences of net.ipv6.conf.all.accept_ra from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv6.conf.all.accept_ra
replace: '#net.ipv6.conf.all.accept_ra'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92473-8
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_ra
- name: Configure Accepting Router Advertisements on All IPv6 Interfaces - Ensure
sysctl net.ipv6.conf.all.accept_ra is set
ansible.posix.sysctl:
name: net.ipv6.conf.all.accept_ra
value: '{{ sysctl_net_ipv6_conf_all_accept_ra_value }}'
sysctl_file: /etc/sysctl.d/net_ipv6_conf_all_accept_ra.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92473-8
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_ra
|
Disable Accepting ICMP Redirects for All IPv6 Interfaces
[ref]ruleTo set the runtime status of the net.ipv6.conf.all.accept_redirects kernel parameter, run the following command: $ sudo sysctl -w net.ipv6.conf.all.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv6.conf.all.accept_redirects = 0 Rationale:An illicit ICMP redirect message could result in a man-in-the-middle attack. Identifiers:
CCE-85708-6 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, SLES-15-040341, 3.3.2, R13, SLES-15-450450075, SV-235020r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv6.conf.all.accept_redirects from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.accept_redirects.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv6.conf.all.accept_redirects" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv6_conf_all_accept_redirects.conf'
sysctl_net_ipv6_conf_all_accept_redirects_value='0'
#
# Set runtime for net.ipv6.conf.all.accept_redirects
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv6.conf.all.accept_redirects="$sysctl_net_ipv6_conf_all_accept_redirects_value"
fi
#
# If net.ipv6.conf.all.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv6.conf.all.accept_redirects = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.accept_redirects")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_accept_redirects_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-85708-6"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85708-6
- DISA-STIG-SLES-15-040341
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_redirects
- name: XCCDF Value sysctl_net_ipv6_conf_all_accept_redirects_value # promote to variable
set_fact:
sysctl_net_ipv6_conf_all_accept_redirects_value: !!str 0
tags:
- always
- name: Disable Accepting ICMP Redirects for All IPv6 Interfaces - Set fact for sysctl
paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85708-6
- DISA-STIG-SLES-15-040341
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_redirects
- name: Disable Accepting ICMP Redirects for All IPv6 Interfaces - Find all files
that contain net.ipv6.conf.all.accept_redirects
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.all.accept_redirects\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85708-6
- DISA-STIG-SLES-15-040341
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_redirects
- name: Disable Accepting ICMP Redirects for All IPv6 Interfaces - Find all files
that set net.ipv6.conf.all.accept_redirects to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.all.accept_redirects\s*=\s*{{ sysctl_net_ipv6_conf_all_accept_redirects_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85708-6
- DISA-STIG-SLES-15-040341
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_redirects
- name: Disable Accepting ICMP Redirects for All IPv6 Interfaces - Comment out any
occurrences of net.ipv6.conf.all.accept_redirects from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv6.conf.all.accept_redirects
replace: '#net.ipv6.conf.all.accept_redirects'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-85708-6
- DISA-STIG-SLES-15-040341
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_redirects
- name: Disable Accepting ICMP Redirects for All IPv6 Interfaces - Comment out any
occurrences of net.ipv6.conf.all.accept_redirects from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv6.conf.all.accept_redirects
replace: '#net.ipv6.conf.all.accept_redirects'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85708-6
- DISA-STIG-SLES-15-040341
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_redirects
- name: Disable Accepting ICMP Redirects for All IPv6 Interfaces - Ensure sysctl net.ipv6.conf.all.accept_redirects
is set
ansible.posix.sysctl:
name: net.ipv6.conf.all.accept_redirects
value: '{{ sysctl_net_ipv6_conf_all_accept_redirects_value }}'
sysctl_file: /etc/sysctl.d/net_ipv6_conf_all_accept_redirects.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85708-6
- DISA-STIG-SLES-15-040341
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_redirects
|
Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces
[ref]ruleTo set the runtime status of the net.ipv6.conf.all.accept_source_route kernel parameter, run the following command: $ sudo sysctl -w net.ipv6.conf.all.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv6.conf.all.accept_source_route = 0 Rationale:Source-routed packets allow the source of the packet to suggest routers
forward the packet along a different path than configured on the router, which can
be used to bypass network security measures. This requirement applies only to the
forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and
the system is functioning as a router.
Accepting source-routed packets in the IPv6 protocol has few legitimate
uses. It should be disabled unless it is absolutely required. Identifiers:
CCE-85649-2 References:
1, 12, 13, 14, 15, 16, 18, 4, 6, 8, 9, APO01.06, APO13.01, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.PT-4, SRG-OS-000480-GPOS-00227, SLES-15-040310, 3.3.1, R13, SLES-15-450450120, SV-235015r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv6.conf.all.accept_source_route from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.accept_source_route.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv6.conf.all.accept_source_route" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv6_conf_all_accept_source_route.conf'
sysctl_net_ipv6_conf_all_accept_source_route_value='0'
#
# Set runtime for net.ipv6.conf.all.accept_source_route
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv6.conf.all.accept_source_route="$sysctl_net_ipv6_conf_all_accept_source_route_value"
fi
#
# If net.ipv6.conf.all.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv6.conf.all.accept_source_route = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.accept_source_route")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_accept_source_route_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-85649-2"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85649-2
- DISA-STIG-SLES-15-040310
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_source_route
- name: XCCDF Value sysctl_net_ipv6_conf_all_accept_source_route_value # promote to variable
set_fact:
sysctl_net_ipv6_conf_all_accept_source_route_value: !!str 0
tags:
- always
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces
- Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85649-2
- DISA-STIG-SLES-15-040310
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces
- Find all files that contain net.ipv6.conf.all.accept_source_route
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.all.accept_source_route\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85649-2
- DISA-STIG-SLES-15-040310
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces
- Find all files that set net.ipv6.conf.all.accept_source_route to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.all.accept_source_route\s*=\s*{{ sysctl_net_ipv6_conf_all_accept_source_route_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85649-2
- DISA-STIG-SLES-15-040310
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces
- Comment out any occurrences of net.ipv6.conf.all.accept_source_route from config
files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv6.conf.all.accept_source_route
replace: '#net.ipv6.conf.all.accept_source_route'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-85649-2
- DISA-STIG-SLES-15-040310
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces
- Comment out any occurrences of net.ipv6.conf.all.accept_source_route from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv6.conf.all.accept_source_route
replace: '#net.ipv6.conf.all.accept_source_route'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85649-2
- DISA-STIG-SLES-15-040310
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces
- Ensure sysctl net.ipv6.conf.all.accept_source_route is set
ansible.posix.sysctl:
name: net.ipv6.conf.all.accept_source_route
value: '{{ sysctl_net_ipv6_conf_all_accept_source_route_value }}'
sysctl_file: /etc/sysctl.d/net_ipv6_conf_all_accept_source_route.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85649-2
- DISA-STIG-SLES-15-040310
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_source_route
|
Disable Kernel Parameter for IPv6 Forwarding
[ref]ruleTo set the runtime status of the net.ipv6.conf.all.forwarding kernel parameter, run the following command: $ sudo sysctl -w net.ipv6.conf.all.forwarding=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv6.conf.all.forwarding = 0 Rationale:IP forwarding permits the kernel to forward packets from one network
interface to another. The ability to forward packets between two networks is
only appropriate for systems acting as routers. Identifiers:
CCE-85713-6 References:
1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv), DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, SLES-15-040381, 3.2.1, SLES-15-450450015, SV-235025r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv6.conf.all.forwarding from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.forwarding.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv6.conf.all.forwarding" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv6_conf_all_forwarding.conf'
sysctl_net_ipv6_conf_all_forwarding_value='0'
#
# Set runtime for net.ipv6.conf.all.forwarding
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv6.conf.all.forwarding="$sysctl_net_ipv6_conf_all_forwarding_value"
fi
#
# If net.ipv6.conf.all.forwarding present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv6.conf.all.forwarding = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.forwarding")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_forwarding_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.forwarding\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.forwarding\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-85713-6"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85713-6
- DISA-STIG-SLES-15-040381
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_forwarding
- name: XCCDF Value sysctl_net_ipv6_conf_all_forwarding_value # promote to variable
set_fact:
sysctl_net_ipv6_conf_all_forwarding_value: !!str 0
tags:
- always
- name: Disable Kernel Parameter for IPv6 Forwarding - Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85713-6
- DISA-STIG-SLES-15-040381
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_forwarding
- name: Disable Kernel Parameter for IPv6 Forwarding - Find all files that contain
net.ipv6.conf.all.forwarding
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.all.forwarding\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85713-6
- DISA-STIG-SLES-15-040381
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_forwarding
- name: Disable Kernel Parameter for IPv6 Forwarding - Find all files that set net.ipv6.conf.all.forwarding
to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.all.forwarding\s*=\s*{{ sysctl_net_ipv6_conf_all_forwarding_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85713-6
- DISA-STIG-SLES-15-040381
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_forwarding
- name: Disable Kernel Parameter for IPv6 Forwarding - Comment out any occurrences
of net.ipv6.conf.all.forwarding from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv6.conf.all.forwarding
replace: '#net.ipv6.conf.all.forwarding'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-85713-6
- DISA-STIG-SLES-15-040381
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_forwarding
- name: Disable Kernel Parameter for IPv6 Forwarding - Comment out any occurrences
of net.ipv6.conf.all.forwarding from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv6.conf.all.forwarding
replace: '#net.ipv6.conf.all.forwarding'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85713-6
- DISA-STIG-SLES-15-040381
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_forwarding
- name: Disable Kernel Parameter for IPv6 Forwarding - Ensure sysctl net.ipv6.conf.all.forwarding
is set
ansible.posix.sysctl:
name: net.ipv6.conf.all.forwarding
value: '{{ sysctl_net_ipv6_conf_all_forwarding_value }}'
sysctl_file: /etc/sysctl.d/net_ipv6_conf_all_forwarding.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85713-6
- DISA-STIG-SLES-15-040381
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_forwarding
|
Disable Accepting Router Advertisements on all IPv6 Interfaces by Default
[ref]ruleTo set the runtime status of the net.ipv6.conf.default.accept_ra kernel parameter, run the following command: $ sudo sysctl -w net.ipv6.conf.default.accept_ra=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv6.conf.default.accept_ra = 0 Rationale:An illicit router advertisement message could result in a man-in-the-middle attack. Identifiers:
CCE-92474-6 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, 3.3.9, SLES-15-450450165 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv6.conf.default.accept_ra from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.accept_ra.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv6.conf.default.accept_ra" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv6_conf_default_accept_ra.conf'
sysctl_net_ipv6_conf_default_accept_ra_value='0'
#
# Set runtime for net.ipv6.conf.default.accept_ra
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv6.conf.default.accept_ra="$sysctl_net_ipv6_conf_default_accept_ra_value"
fi
#
# If net.ipv6.conf.default.accept_ra present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv6.conf.default.accept_ra = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.accept_ra")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_accept_ra_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.accept_ra\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.accept_ra\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-92474-6"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92474-6
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_ra
- name: XCCDF Value sysctl_net_ipv6_conf_default_accept_ra_value # promote to variable
set_fact:
sysctl_net_ipv6_conf_default_accept_ra_value: !!str 0
tags:
- always
- name: Disable Accepting Router Advertisements on all IPv6 Interfaces by Default
- Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92474-6
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_ra
- name: Disable Accepting Router Advertisements on all IPv6 Interfaces by Default
- Find all files that contain net.ipv6.conf.default.accept_ra
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.default.accept_ra\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92474-6
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_ra
- name: Disable Accepting Router Advertisements on all IPv6 Interfaces by Default
- Find all files that set net.ipv6.conf.default.accept_ra to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.default.accept_ra\s*=\s*{{ sysctl_net_ipv6_conf_default_accept_ra_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92474-6
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_ra
- name: Disable Accepting Router Advertisements on all IPv6 Interfaces by Default
- Comment out any occurrences of net.ipv6.conf.default.accept_ra from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv6.conf.default.accept_ra
replace: '#net.ipv6.conf.default.accept_ra'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-92474-6
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_ra
- name: Disable Accepting Router Advertisements on all IPv6 Interfaces by Default
- Comment out any occurrences of net.ipv6.conf.default.accept_ra from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv6.conf.default.accept_ra
replace: '#net.ipv6.conf.default.accept_ra'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92474-6
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_ra
- name: Disable Accepting Router Advertisements on all IPv6 Interfaces by Default
- Ensure sysctl net.ipv6.conf.default.accept_ra is set
ansible.posix.sysctl:
name: net.ipv6.conf.default.accept_ra
value: '{{ sysctl_net_ipv6_conf_default_accept_ra_value }}'
sysctl_file: /etc/sysctl.d/net_ipv6_conf_default_accept_ra.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92474-6
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_ra
|
Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces
[ref]ruleTo set the runtime status of the net.ipv6.conf.default.accept_redirects kernel parameter, run the following command: $ sudo sysctl -w net.ipv6.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv6.conf.default.accept_redirects = 0 Rationale:An illicit ICMP redirect message could result in a man-in-the-middle attack. Identifiers:
CCE-85722-7 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-6(b), CM-6.1(iv), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, SLES-15-040350, 3.3.2, R13, SLES-15-450450075, SV-235021r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv6.conf.default.accept_redirects from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.accept_redirects.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv6.conf.default.accept_redirects" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv6_conf_default_accept_redirects.conf'
sysctl_net_ipv6_conf_default_accept_redirects_value='0'
#
# Set runtime for net.ipv6.conf.default.accept_redirects
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv6.conf.default.accept_redirects="$sysctl_net_ipv6_conf_default_accept_redirects_value"
fi
#
# If net.ipv6.conf.default.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv6.conf.default.accept_redirects = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.accept_redirects")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_accept_redirects_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-85722-7"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85722-7
- DISA-STIG-SLES-15-040350
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_redirects
- name: XCCDF Value sysctl_net_ipv6_conf_default_accept_redirects_value # promote to variable
set_fact:
sysctl_net_ipv6_conf_default_accept_redirects_value: !!str 0
tags:
- always
- name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces
- Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85722-7
- DISA-STIG-SLES-15-040350
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_redirects
- name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces
- Find all files that contain net.ipv6.conf.default.accept_redirects
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.default.accept_redirects\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85722-7
- DISA-STIG-SLES-15-040350
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_redirects
- name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces
- Find all files that set net.ipv6.conf.default.accept_redirects to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.default.accept_redirects\s*=\s*{{ sysctl_net_ipv6_conf_default_accept_redirects_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85722-7
- DISA-STIG-SLES-15-040350
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_redirects
- name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces
- Comment out any occurrences of net.ipv6.conf.default.accept_redirects from config
files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv6.conf.default.accept_redirects
replace: '#net.ipv6.conf.default.accept_redirects'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-85722-7
- DISA-STIG-SLES-15-040350
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_redirects
- name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces
- Comment out any occurrences of net.ipv6.conf.default.accept_redirects from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv6.conf.default.accept_redirects
replace: '#net.ipv6.conf.default.accept_redirects'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85722-7
- DISA-STIG-SLES-15-040350
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_redirects
- name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces
- Ensure sysctl net.ipv6.conf.default.accept_redirects is set
ansible.posix.sysctl:
name: net.ipv6.conf.default.accept_redirects
value: '{{ sysctl_net_ipv6_conf_default_accept_redirects_value }}'
sysctl_file: /etc/sysctl.d/net_ipv6_conf_default_accept_redirects.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85722-7
- DISA-STIG-SLES-15-040350
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_redirects
|
Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces by Default
[ref]ruleTo set the runtime status of the net.ipv6.conf.default.accept_source_route kernel parameter, run the following command: $ sudo sysctl -w net.ipv6.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv6.conf.default.accept_source_route = 0 Rationale:Source-routed packets allow the source of the packet to suggest routers
forward the packet along a different path than configured on the router, which can
be used to bypass network security measures. This requirement applies only to the
forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and
the system is functioning as a router.
Accepting source-routed packets in the IPv6 protocol has few legitimate
uses. It should be disabled unless it is absolutely required. Identifiers:
CCE-85653-4 References:
1, 12, 13, 14, 15, 16, 18, 4, 6, 8, 9, APO01.06, APO13.01, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv), DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227, SLES-15-040321, 3.3.1, R13, SLES-15-450450120, 1.4.2, 1.4, SV-235017r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv6.conf.default.accept_source_route from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.accept_source_route.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv6.conf.default.accept_source_route" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv6_conf_default_accept_source_route.conf'
sysctl_net_ipv6_conf_default_accept_source_route_value='0'
#
# Set runtime for net.ipv6.conf.default.accept_source_route
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv6.conf.default.accept_source_route="$sysctl_net_ipv6_conf_default_accept_source_route_value"
fi
#
# If net.ipv6.conf.default.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv6.conf.default.accept_source_route = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.accept_source_route")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_accept_source_route_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-85653-4"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85653-4
- DISA-STIG-SLES-15-040321
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_source_route
- name: XCCDF Value sysctl_net_ipv6_conf_default_accept_source_route_value # promote to variable
set_fact:
sysctl_net_ipv6_conf_default_accept_source_route_value: !!str 0
tags:
- always
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces
by Default - Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85653-4
- DISA-STIG-SLES-15-040321
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces
by Default - Find all files that contain net.ipv6.conf.default.accept_source_route
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.default.accept_source_route\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85653-4
- DISA-STIG-SLES-15-040321
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces
by Default - Find all files that set net.ipv6.conf.default.accept_source_route
to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.default.accept_source_route\s*=\s*{{ sysctl_net_ipv6_conf_default_accept_source_route_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85653-4
- DISA-STIG-SLES-15-040321
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces
by Default - Comment out any occurrences of net.ipv6.conf.default.accept_source_route
from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv6.conf.default.accept_source_route
replace: '#net.ipv6.conf.default.accept_source_route'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-85653-4
- DISA-STIG-SLES-15-040321
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces
by Default - Comment out any occurrences of net.ipv6.conf.default.accept_source_route
from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv6.conf.default.accept_source_route
replace: '#net.ipv6.conf.default.accept_source_route'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85653-4
- DISA-STIG-SLES-15-040321
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces
by Default - Ensure sysctl net.ipv6.conf.default.accept_source_route is set
ansible.posix.sysctl:
name: net.ipv6.conf.default.accept_source_route
value: '{{ sysctl_net_ipv6_conf_default_accept_source_route_value }}'
sysctl_file: /etc/sysctl.d/net_ipv6_conf_default_accept_source_route.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85653-4
- DISA-STIG-SLES-15-040321
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_source_route
|
Kernel Parameters Which Affect Networking
[ref]groupThe sysctl utility is used to set
parameters which affect the operation of the Linux kernel. Kernel parameters
which affect networking and have security implications are described here. |
| contains 17 rules |
Network Related Kernel Runtime Parameters for Hosts and Routers
[ref]groupCertain kernel parameters should be set for systems which are
acting as either hosts or routers to improve the system's ability defend
against certain types of IPv4 protocol attacks. |
| contains 14 rules |
Disable Accepting ICMP Redirects for All IPv4 Interfaces
[ref]ruleTo set the runtime status of the net.ipv4.conf.all.accept_redirects kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.all.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.all.accept_redirects = 0 Rationale:ICMP redirect messages are used by routers to inform hosts that a more
direct route exists for a particular destination. These messages modify the
host's route table and are unauthenticated. An illicit ICMP redirect
message could result in a man-in-the-middle attack.
This feature of the IPv4 protocol has few legitimate uses. It should be
disabled unless absolutely required." Identifiers:
CCE-85651-8 References:
1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, 5.10.1.1, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, SLES-15-040330, 3.3.2, R12, SLES-15-450450075, SV-235018r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.conf.all.accept_redirects from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.accept_redirects.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.conf.all.accept_redirects" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_conf_all_accept_redirects.conf'
sysctl_net_ipv4_conf_all_accept_redirects_value='0'
#
# Set runtime for net.ipv4.conf.all.accept_redirects
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.conf.all.accept_redirects="$sysctl_net_ipv4_conf_all_accept_redirects_value"
fi
#
# If net.ipv4.conf.all.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv4.conf.all.accept_redirects = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.accept_redirects")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_accept_redirects_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-85651-8"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85651-8
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040330
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_redirects
- name: XCCDF Value sysctl_net_ipv4_conf_all_accept_redirects_value # promote to variable
set_fact:
sysctl_net_ipv4_conf_all_accept_redirects_value: !!str 0
tags:
- always
- name: Disable Accepting ICMP Redirects for All IPv4 Interfaces - Set fact for sysctl
paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85651-8
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040330
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_redirects
- name: Disable Accepting ICMP Redirects for All IPv4 Interfaces - Find all files
that contain net.ipv4.conf.all.accept_redirects
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.accept_redirects\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85651-8
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040330
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_redirects
- name: Disable Accepting ICMP Redirects for All IPv4 Interfaces - Find all files
that set net.ipv4.conf.all.accept_redirects to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.accept_redirects\s*=\s*{{ sysctl_net_ipv4_conf_all_accept_redirects_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85651-8
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040330
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_redirects
- name: Disable Accepting ICMP Redirects for All IPv4 Interfaces - Comment out any
occurrences of net.ipv4.conf.all.accept_redirects from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.all.accept_redirects
replace: '#net.ipv4.conf.all.accept_redirects'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-85651-8
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040330
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_redirects
- name: Disable Accepting ICMP Redirects for All IPv4 Interfaces - Comment out any
occurrences of net.ipv4.conf.all.accept_redirects from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.conf.all.accept_redirects
replace: '#net.ipv4.conf.all.accept_redirects'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85651-8
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040330
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_redirects
- name: Disable Accepting ICMP Redirects for All IPv4 Interfaces - Ensure sysctl net.ipv4.conf.all.accept_redirects
is set
ansible.posix.sysctl:
name: net.ipv4.conf.all.accept_redirects
value: '{{ sysctl_net_ipv4_conf_all_accept_redirects_value }}'
sysctl_file: /etc/sysctl.d/net_ipv4_conf_all_accept_redirects.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85651-8
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040330
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_redirects
|
Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces
[ref]ruleTo set the runtime status of the net.ipv4.conf.all.accept_source_route kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.all.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.all.accept_source_route = 0 Rationale:Source-routed packets allow the source of the packet to suggest routers
forward the packet along a different path than configured on the router,
which can be used to bypass network security measures. This requirement
applies only to the forwarding of source-routerd traffic, such as when IPv4
forwarding is enabled and the system is functioning as a router.
Accepting source-routed packets in the IPv4 protocol has few legitimate
uses. It should be disabled unless it is absolutely required. Identifiers:
CCE-85648-4 References:
1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, SLES-15-040300, 3.3.1, R12, SLES-15-450450120, SV-235014r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.conf.all.accept_source_route from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.accept_source_route.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.conf.all.accept_source_route" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_conf_all_accept_source_route.conf'
sysctl_net_ipv4_conf_all_accept_source_route_value='0'
#
# Set runtime for net.ipv4.conf.all.accept_source_route
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.conf.all.accept_source_route="$sysctl_net_ipv4_conf_all_accept_source_route_value"
fi
#
# If net.ipv4.conf.all.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv4.conf.all.accept_source_route = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.accept_source_route")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_accept_source_route_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-85648-4"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85648-4
- DISA-STIG-SLES-15-040300
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_source_route
- name: XCCDF Value sysctl_net_ipv4_conf_all_accept_source_route_value # promote to variable
set_fact:
sysctl_net_ipv4_conf_all_accept_source_route_value: !!str 0
tags:
- always
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces
- Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85648-4
- DISA-STIG-SLES-15-040300
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces
- Find all files that contain net.ipv4.conf.all.accept_source_route
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.accept_source_route\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85648-4
- DISA-STIG-SLES-15-040300
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces
- Find all files that set net.ipv4.conf.all.accept_source_route to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.accept_source_route\s*=\s*{{ sysctl_net_ipv4_conf_all_accept_source_route_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85648-4
- DISA-STIG-SLES-15-040300
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces
- Comment out any occurrences of net.ipv4.conf.all.accept_source_route from config
files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.all.accept_source_route
replace: '#net.ipv4.conf.all.accept_source_route'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-85648-4
- DISA-STIG-SLES-15-040300
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces
- Comment out any occurrences of net.ipv4.conf.all.accept_source_route from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.conf.all.accept_source_route
replace: '#net.ipv4.conf.all.accept_source_route'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85648-4
- DISA-STIG-SLES-15-040300
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces
- Ensure sysctl net.ipv4.conf.all.accept_source_route is set
ansible.posix.sysctl:
name: net.ipv4.conf.all.accept_source_route
value: '{{ sysctl_net_ipv4_conf_all_accept_source_route_value }}'
sysctl_file: /etc/sysctl.d/net_ipv4_conf_all_accept_source_route.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85648-4
- DISA-STIG-SLES-15-040300
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_source_route
|
Configure ARP filtering for All IPv4 Interfaces
[ref]ruleTo set the runtime status of the net.ipv4.conf.all.arp_filter kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.all.arp_filter=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.all.arp_filter = 0 Warning:
This behaviour may cause problems to system on a high availability or load balancing configuration. Rationale:Prevents the Linux Kernel from handling the ARP table globally.
By default, the kernel may respond to an ARP request from a certain interface with information
from another interface. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.conf.all.arp_filter from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.arp_filter.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.conf.all.arp_filter" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_conf_all_arp_filter.conf'
sysctl_net_ipv4_conf_all_arp_filter_value='0'
#
# Set runtime for net.ipv4.conf.all.arp_filter
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.conf.all.arp_filter="$sysctl_net_ipv4_conf_all_arp_filter_value"
fi
#
# If net.ipv4.conf.all.arp_filter present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv4.conf.all.arp_filter = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.arp_filter")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_arp_filter_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.arp_filter\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.arp_filter\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-92609-7"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92609-7
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_arp_filter
- name: XCCDF Value sysctl_net_ipv4_conf_all_arp_filter_value # promote to variable
set_fact:
sysctl_net_ipv4_conf_all_arp_filter_value: !!str 0
tags:
- always
- name: Configure ARP filtering for All IPv4 Interfaces - Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92609-7
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_arp_filter
- name: Configure ARP filtering for All IPv4 Interfaces - Find all files that contain
net.ipv4.conf.all.arp_filter
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.arp_filter\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92609-7
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_arp_filter
- name: Configure ARP filtering for All IPv4 Interfaces - Find all files that set
net.ipv4.conf.all.arp_filter to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.arp_filter\s*=\s*{{ sysctl_net_ipv4_conf_all_arp_filter_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92609-7
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_arp_filter
- name: Configure ARP filtering for All IPv4 Interfaces - Comment out any occurrences
of net.ipv4.conf.all.arp_filter from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.all.arp_filter
replace: '#net.ipv4.conf.all.arp_filter'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-92609-7
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_arp_filter
- name: Configure ARP filtering for All IPv4 Interfaces - Comment out any occurrences
of net.ipv4.conf.all.arp_filter from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.conf.all.arp_filter
replace: '#net.ipv4.conf.all.arp_filter'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92609-7
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_arp_filter
- name: Configure ARP filtering for All IPv4 Interfaces - Ensure sysctl net.ipv4.conf.all.arp_filter
is set
ansible.posix.sysctl:
name: net.ipv4.conf.all.arp_filter
value: '{{ sysctl_net_ipv4_conf_all_arp_filter_value }}'
sysctl_file: /etc/sysctl.d/net_ipv4_conf_all_arp_filter.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92609-7
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_arp_filter
|
Configure Response Mode of ARP Requests for All IPv4 Interfaces
[ref]ruleTo set the runtime status of the net.ipv4.conf.all.arp_ignore kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.all.arp_ignore=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.all.arp_ignore = 0 Warning:
The ARP response mode may impact behaviour of workloads and firewalls on the system. Rationale:Avoids ARP Flux on system that have more than one interface on the same subnet. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.conf.all.arp_ignore from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.arp_ignore.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.conf.all.arp_ignore" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_conf_all_arp_ignore.conf'
sysctl_net_ipv4_conf_all_arp_ignore_value='0'
#
# Set runtime for net.ipv4.conf.all.arp_ignore
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.conf.all.arp_ignore="$sysctl_net_ipv4_conf_all_arp_ignore_value"
fi
#
# If net.ipv4.conf.all.arp_ignore present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv4.conf.all.arp_ignore = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.arp_ignore")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_arp_ignore_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.arp_ignore\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.arp_ignore\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-92610-5"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92610-5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_arp_ignore
- name: XCCDF Value sysctl_net_ipv4_conf_all_arp_ignore_value # promote to variable
set_fact:
sysctl_net_ipv4_conf_all_arp_ignore_value: !!str 0
tags:
- always
- name: Configure Response Mode of ARP Requests for All IPv4 Interfaces - Set fact
for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92610-5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_arp_ignore
- name: Configure Response Mode of ARP Requests for All IPv4 Interfaces - Find all
files that contain net.ipv4.conf.all.arp_ignore
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.arp_ignore\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92610-5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_arp_ignore
- name: Configure Response Mode of ARP Requests for All IPv4 Interfaces - Find all
files that set net.ipv4.conf.all.arp_ignore to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.arp_ignore\s*=\s*{{ sysctl_net_ipv4_conf_all_arp_ignore_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92610-5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_arp_ignore
- name: Configure Response Mode of ARP Requests for All IPv4 Interfaces - Comment
out any occurrences of net.ipv4.conf.all.arp_ignore from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.all.arp_ignore
replace: '#net.ipv4.conf.all.arp_ignore'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-92610-5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_arp_ignore
- name: Configure Response Mode of ARP Requests for All IPv4 Interfaces - Comment
out any occurrences of net.ipv4.conf.all.arp_ignore from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.conf.all.arp_ignore
replace: '#net.ipv4.conf.all.arp_ignore'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92610-5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_arp_ignore
- name: Configure Response Mode of ARP Requests for All IPv4 Interfaces - Ensure sysctl
net.ipv4.conf.all.arp_ignore is set
ansible.posix.sysctl:
name: net.ipv4.conf.all.arp_ignore
value: '{{ sysctl_net_ipv4_conf_all_arp_ignore_value }}'
sysctl_file: /etc/sysctl.d/net_ipv4_conf_all_arp_ignore.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92610-5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_arp_ignore
|
Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces
[ref]ruleTo set the runtime status of the net.ipv4.conf.all.log_martians kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.all.log_martians=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.all.log_martians = 1 Rationale:The presence of "martian" packets (which have impossible addresses)
as well as spoofed packets, source-routed packets, and redirects could be a
sign of nefarious network activity. Logging these packets enables this activity
to be detected. Identifiers:
CCE-91222-0 References:
1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.04, DSS03.05, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.11.2.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), SC-5(3)(a), DE.CM-1, PR.AC-3, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, 3.3.4, SLES-15-450450135 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.conf.all.log_martians from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.log_martians.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.conf.all.log_martians" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_conf_all_log_martians.conf'
sysctl_net_ipv4_conf_all_log_martians_value='1'
#
# Set runtime for net.ipv4.conf.all.log_martians
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.conf.all.log_martians="$sysctl_net_ipv4_conf_all_log_martians_value"
fi
#
# If net.ipv4.conf.all.log_martians present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv4.conf.all.log_martians = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.log_martians")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_log_martians_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.log_martians\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.log_martians\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-91222-0"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91222-0
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_all_log_martians
- unknown_severity
- name: XCCDF Value sysctl_net_ipv4_conf_all_log_martians_value # promote to variable
set_fact:
sysctl_net_ipv4_conf_all_log_martians_value: !!str 1
tags:
- always
- name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces - Set
fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91222-0
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_all_log_martians
- unknown_severity
- name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces - Find
all files that contain net.ipv4.conf.all.log_martians
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.log_martians\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91222-0
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_all_log_martians
- unknown_severity
- name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces - Find
all files that set net.ipv4.conf.all.log_martians to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.log_martians\s*=\s*{{ sysctl_net_ipv4_conf_all_log_martians_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91222-0
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_all_log_martians
- unknown_severity
- name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces - Comment
out any occurrences of net.ipv4.conf.all.log_martians from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.all.log_martians
replace: '#net.ipv4.conf.all.log_martians'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-91222-0
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_all_log_martians
- unknown_severity
- name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces - Comment
out any occurrences of net.ipv4.conf.all.log_martians from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.conf.all.log_martians
replace: '#net.ipv4.conf.all.log_martians'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91222-0
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_all_log_martians
- unknown_severity
- name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces - Ensure
sysctl net.ipv4.conf.all.log_martians is set
ansible.posix.sysctl:
name: net.ipv4.conf.all.log_martians
value: '{{ sysctl_net_ipv4_conf_all_log_martians_value }}'
sysctl_file: /etc/sysctl.d/net_ipv4_conf_all_log_martians.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91222-0
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_all_log_martians
- unknown_severity
|
Prevent Routing External Traffic to Local Loopback on All IPv4 Interfaces
[ref]ruleTo set the runtime status of the net.ipv4.conf.all.route_localnet kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.all.route_localnet=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.all.route_localnet = 0 Rationale:Refuse the routing of packets whose source or destination address is the local loopback.
This prohibits the use of network 127/8 for local routing purposes.
Enabling route_localnet can expose applications listening on localhost to external traffic. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.conf.all.route_localnet from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.route_localnet.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.conf.all.route_localnet" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_conf_all_route_localnet.conf'
#
# Set runtime for net.ipv4.conf.all.route_localnet
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.conf.all.route_localnet="0"
fi
#
# If net.ipv4.conf.all.route_localnet present in /etc/sysctl.conf, change value to "0"
# else, add "net.ipv4.conf.all.route_localnet = 0" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.route_localnet")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.route_localnet\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.route_localnet\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-92611-3"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92611-3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_route_localnet
- name: Prevent Routing External Traffic to Local Loopback on All IPv4 Interfaces
- Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92611-3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_route_localnet
- name: Prevent Routing External Traffic to Local Loopback on All IPv4 Interfaces
- Find all files that contain net.ipv4.conf.all.route_localnet
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.route_localnet\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92611-3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_route_localnet
- name: Prevent Routing External Traffic to Local Loopback on All IPv4 Interfaces
- Find all files that set net.ipv4.conf.all.route_localnet to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.route_localnet\s*=\s*0$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92611-3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_route_localnet
- name: Prevent Routing External Traffic to Local Loopback on All IPv4 Interfaces
- Comment out any occurrences of net.ipv4.conf.all.route_localnet from config
files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.all.route_localnet
replace: '#net.ipv4.conf.all.route_localnet'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-92611-3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_route_localnet
- name: Prevent Routing External Traffic to Local Loopback on All IPv4 Interfaces
- Comment out any occurrences of net.ipv4.conf.all.route_localnet from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.conf.all.route_localnet
replace: '#net.ipv4.conf.all.route_localnet'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92611-3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_route_localnet
- name: Prevent Routing External Traffic to Local Loopback on All IPv4 Interfaces
- Ensure sysctl net.ipv4.conf.all.route_localnet is set to 0
ansible.posix.sysctl:
name: net.ipv4.conf.all.route_localnet
value: '0'
sysctl_file: /etc/sysctl.d/net_ipv4_conf_all_route_localnet.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92611-3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_route_localnet
|
Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces
[ref]ruleTo set the runtime status of the net.ipv4.conf.all.secure_redirects kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.all.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.all.secure_redirects = 0 Rationale:Accepting "secure" ICMP redirects (from those gateways listed as
default gateways) has few legitimate uses. It should be disabled unless it is
absolutely required. Identifiers:
CCE-91220-4 References:
1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227, 3.3.3, R12, SLES-15-450450090, 1.4.3, 1.4 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.conf.all.secure_redirects from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.secure_redirects.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.conf.all.secure_redirects" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_conf_all_secure_redirects.conf'
sysctl_net_ipv4_conf_all_secure_redirects_value='0'
#
# Set runtime for net.ipv4.conf.all.secure_redirects
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.conf.all.secure_redirects="$sysctl_net_ipv4_conf_all_secure_redirects_value"
fi
#
# If net.ipv4.conf.all.secure_redirects present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv4.conf.all.secure_redirects = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.secure_redirects")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_secure_redirects_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.secure_redirects\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.secure_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-91220-4"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91220-4
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_secure_redirects
- name: XCCDF Value sysctl_net_ipv4_conf_all_secure_redirects_value # promote to variable
set_fact:
sysctl_net_ipv4_conf_all_secure_redirects_value: !!str 0
tags:
- always
- name: Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces
- Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91220-4
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_secure_redirects
- name: Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces
- Find all files that contain net.ipv4.conf.all.secure_redirects
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.secure_redirects\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91220-4
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_secure_redirects
- name: Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces
- Find all files that set net.ipv4.conf.all.secure_redirects to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.secure_redirects\s*=\s*{{ sysctl_net_ipv4_conf_all_secure_redirects_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91220-4
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_secure_redirects
- name: Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces
- Comment out any occurrences of net.ipv4.conf.all.secure_redirects from config
files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.all.secure_redirects
replace: '#net.ipv4.conf.all.secure_redirects'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-91220-4
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_secure_redirects
- name: Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces
- Comment out any occurrences of net.ipv4.conf.all.secure_redirects from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.conf.all.secure_redirects
replace: '#net.ipv4.conf.all.secure_redirects'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91220-4
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_secure_redirects
- name: Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces
- Ensure sysctl net.ipv4.conf.all.secure_redirects is set
ansible.posix.sysctl:
name: net.ipv4.conf.all.secure_redirects
value: '{{ sysctl_net_ipv4_conf_all_secure_redirects_value }}'
sysctl_file: /etc/sysctl.d/net_ipv4_conf_all_secure_redirects.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91220-4
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_secure_redirects
|
Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces
[ref]ruleTo set the runtime status of the net.ipv4.conf.default.accept_redirects kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.default.accept_redirects = 0 Rationale:ICMP redirect messages are used by routers to inform hosts that a more
direct route exists for a particular destination. These messages modify the
host's route table and are unauthenticated. An illicit ICMP redirect
message could result in a man-in-the-middle attack.
This feature of the IPv4 protocol has few legitimate uses. It should
be disabled unless absolutely required. Identifiers:
CCE-85652-6 References:
1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227, SLES-15-040340, 3.3.3, R12, SLES-15-450450075, 1.4.3, 1.4, SV-235019r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.conf.default.accept_redirects from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.accept_redirects.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.conf.default.accept_redirects" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_conf_default_accept_redirects.conf'
sysctl_net_ipv4_conf_default_accept_redirects_value='0'
#
# Set runtime for net.ipv4.conf.default.accept_redirects
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.conf.default.accept_redirects="$sysctl_net_ipv4_conf_default_accept_redirects_value"
fi
#
# If net.ipv4.conf.default.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv4.conf.default.accept_redirects = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.accept_redirects")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_accept_redirects_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-85652-6"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85652-6
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040340
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_redirects
- name: XCCDF Value sysctl_net_ipv4_conf_default_accept_redirects_value # promote to variable
set_fact:
sysctl_net_ipv4_conf_default_accept_redirects_value: !!str 0
tags:
- always
- name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces
- Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85652-6
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040340
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_redirects
- name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces
- Find all files that contain net.ipv4.conf.default.accept_redirects
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.accept_redirects\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85652-6
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040340
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_redirects
- name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces
- Find all files that set net.ipv4.conf.default.accept_redirects to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.accept_redirects\s*=\s*{{ sysctl_net_ipv4_conf_default_accept_redirects_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85652-6
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040340
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_redirects
- name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces
- Comment out any occurrences of net.ipv4.conf.default.accept_redirects from config
files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.default.accept_redirects
replace: '#net.ipv4.conf.default.accept_redirects'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-85652-6
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040340
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_redirects
- name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces
- Comment out any occurrences of net.ipv4.conf.default.accept_redirects from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.conf.default.accept_redirects
replace: '#net.ipv4.conf.default.accept_redirects'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85652-6
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040340
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_redirects
- name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces
- Ensure sysctl net.ipv4.conf.default.accept_redirects is set
ansible.posix.sysctl:
name: net.ipv4.conf.default.accept_redirects
value: '{{ sysctl_net_ipv4_conf_default_accept_redirects_value }}'
sysctl_file: /etc/sysctl.d/net_ipv4_conf_default_accept_redirects.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85652-6
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040340
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_redirects
|
Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces by Default
[ref]ruleTo set the runtime status of the net.ipv4.conf.default.accept_source_route kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.default.accept_source_route = 0 Rationale:Source-routed packets allow the source of the packet to suggest routers
forward the packet along a different path than configured on the router,
which can be used to bypass network security measures.
Accepting source-routed packets in the IPv4 protocol has few legitimate
uses. It should be disabled unless it is absolutely required, such as when
IPv4 forwarding is enabled and the system is legitimately functioning as a
router. Identifiers:
CCE-85650-0 References:
1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, SLES-15-040320, 3.3.1, R12, SLES-15-450450120, SV-235016r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.conf.default.accept_source_route from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.accept_source_route.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.conf.default.accept_source_route" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_conf_default_accept_source_route.conf'
sysctl_net_ipv4_conf_default_accept_source_route_value='0'
#
# Set runtime for net.ipv4.conf.default.accept_source_route
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.conf.default.accept_source_route="$sysctl_net_ipv4_conf_default_accept_source_route_value"
fi
#
# If net.ipv4.conf.default.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv4.conf.default.accept_source_route = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.accept_source_route")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_accept_source_route_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-85650-0"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85650-0
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040320
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_source_route
- name: XCCDF Value sysctl_net_ipv4_conf_default_accept_source_route_value # promote to variable
set_fact:
sysctl_net_ipv4_conf_default_accept_source_route_value: !!str 0
tags:
- always
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces
by Default - Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85650-0
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040320
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces
by Default - Find all files that contain net.ipv4.conf.default.accept_source_route
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.accept_source_route\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85650-0
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040320
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces
by Default - Find all files that set net.ipv4.conf.default.accept_source_route
to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.accept_source_route\s*=\s*{{ sysctl_net_ipv4_conf_default_accept_source_route_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85650-0
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040320
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces
by Default - Comment out any occurrences of net.ipv4.conf.default.accept_source_route
from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.default.accept_source_route
replace: '#net.ipv4.conf.default.accept_source_route'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-85650-0
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040320
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces
by Default - Comment out any occurrences of net.ipv4.conf.default.accept_source_route
from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.conf.default.accept_source_route
replace: '#net.ipv4.conf.default.accept_source_route'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85650-0
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040320
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces
by Default - Ensure sysctl net.ipv4.conf.default.accept_source_route is set
ansible.posix.sysctl:
name: net.ipv4.conf.default.accept_source_route
value: '{{ sysctl_net_ipv4_conf_default_accept_source_route_value }}'
sysctl_file: /etc/sysctl.d/net_ipv4_conf_default_accept_source_route.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85650-0
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040320
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_source_route
|
Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces by Default
[ref]ruleTo set the runtime status of the net.ipv4.conf.default.log_martians kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.default.log_martians=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.default.log_martians = 1 Rationale:The presence of "martian" packets (which have impossible addresses)
as well as spoofed packets, source-routed packets, and redirects could be a
sign of nefarious network activity. Logging these packets enables this activity
to be detected. Identifiers:
CCE-92482-9 References:
1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.04, DSS03.05, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.11.2.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), SC-5(3)(a), DE.CM-1, PR.AC-3, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, 3.3.4, SLES-15-450450135 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.conf.default.log_martians from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.log_martians.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.conf.default.log_martians" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_conf_default_log_martians.conf'
sysctl_net_ipv4_conf_default_log_martians_value='1'
#
# Set runtime for net.ipv4.conf.default.log_martians
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.conf.default.log_martians="$sysctl_net_ipv4_conf_default_log_martians_value"
fi
#
# If net.ipv4.conf.default.log_martians present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv4.conf.default.log_martians = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.log_martians")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_log_martians_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.log_martians\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.log_martians\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-92482-9"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92482-9
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_default_log_martians
- unknown_severity
- name: XCCDF Value sysctl_net_ipv4_conf_default_log_martians_value # promote to variable
set_fact:
sysctl_net_ipv4_conf_default_log_martians_value: !!str 1
tags:
- always
- name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces by Default
- Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92482-9
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_default_log_martians
- unknown_severity
- name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces by Default
- Find all files that contain net.ipv4.conf.default.log_martians
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.log_martians\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92482-9
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_default_log_martians
- unknown_severity
- name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces by Default
- Find all files that set net.ipv4.conf.default.log_martians to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.log_martians\s*=\s*{{ sysctl_net_ipv4_conf_default_log_martians_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92482-9
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_default_log_martians
- unknown_severity
- name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces by Default
- Comment out any occurrences of net.ipv4.conf.default.log_martians from config
files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.default.log_martians
replace: '#net.ipv4.conf.default.log_martians'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-92482-9
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_default_log_martians
- unknown_severity
- name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces by Default
- Comment out any occurrences of net.ipv4.conf.default.log_martians from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.conf.default.log_martians
replace: '#net.ipv4.conf.default.log_martians'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92482-9
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_default_log_martians
- unknown_severity
- name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces by Default
- Ensure sysctl net.ipv4.conf.default.log_martians is set
ansible.posix.sysctl:
name: net.ipv4.conf.default.log_martians
value: '{{ sysctl_net_ipv4_conf_default_log_martians_value }}'
sysctl_file: /etc/sysctl.d/net_ipv4_conf_default_log_martians.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92482-9
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_default_log_martians
- unknown_severity
|
Configure Kernel Parameter for Accepting Secure Redirects By Default
[ref]ruleTo set the runtime status of the net.ipv4.conf.default.secure_redirects kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.default.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.default.secure_redirects = 0 Rationale:Accepting "secure" ICMP redirects (from those gateways listed as
default gateways) has few legitimate uses. It should be disabled unless it is
absolutely required. Identifiers:
CCE-91221-2 References:
1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, 3.3.2, R12, SLES-15-450450090 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.conf.default.secure_redirects from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.secure_redirects.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.conf.default.secure_redirects" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_conf_default_secure_redirects.conf'
sysctl_net_ipv4_conf_default_secure_redirects_value='0'
#
# Set runtime for net.ipv4.conf.default.secure_redirects
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.conf.default.secure_redirects="$sysctl_net_ipv4_conf_default_secure_redirects_value"
fi
#
# If net.ipv4.conf.default.secure_redirects present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv4.conf.default.secure_redirects = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.secure_redirects")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_secure_redirects_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.secure_redirects\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.secure_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-91221-2"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91221-2
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_secure_redirects
- name: XCCDF Value sysctl_net_ipv4_conf_default_secure_redirects_value # promote to variable
set_fact:
sysctl_net_ipv4_conf_default_secure_redirects_value: !!str 0
tags:
- always
- name: Configure Kernel Parameter for Accepting Secure Redirects By Default - Set
fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91221-2
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_secure_redirects
- name: Configure Kernel Parameter for Accepting Secure Redirects By Default - Find
all files that contain net.ipv4.conf.default.secure_redirects
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.secure_redirects\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91221-2
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_secure_redirects
- name: Configure Kernel Parameter for Accepting Secure Redirects By Default - Find
all files that set net.ipv4.conf.default.secure_redirects to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.secure_redirects\s*=\s*{{ sysctl_net_ipv4_conf_default_secure_redirects_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91221-2
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_secure_redirects
- name: Configure Kernel Parameter for Accepting Secure Redirects By Default - Comment
out any occurrences of net.ipv4.conf.default.secure_redirects from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.default.secure_redirects
replace: '#net.ipv4.conf.default.secure_redirects'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-91221-2
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_secure_redirects
- name: Configure Kernel Parameter for Accepting Secure Redirects By Default - Comment
out any occurrences of net.ipv4.conf.default.secure_redirects from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.conf.default.secure_redirects
replace: '#net.ipv4.conf.default.secure_redirects'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91221-2
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_secure_redirects
- name: Configure Kernel Parameter for Accepting Secure Redirects By Default - Ensure
sysctl net.ipv4.conf.default.secure_redirects is set
ansible.posix.sysctl:
name: net.ipv4.conf.default.secure_redirects
value: '{{ sysctl_net_ipv4_conf_default_secure_redirects_value }}'
sysctl_file: /etc/sysctl.d/net_ipv4_conf_default_secure_redirects.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91221-2
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_secure_redirects
|
Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces
[ref]ruleTo set the runtime status of the net.ipv4.icmp_echo_ignore_broadcasts kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.icmp_echo_ignore_broadcasts = 1 Rationale:Responding to broadcast (ICMP) echoes facilitates network mapping
and provides a vector for amplification attacks.
Ignoring ICMP echo requests (pings) sent to broadcast or multicast
addresses makes the system slightly more difficult to enumerate on the network. Identifiers:
CCE-91243-6 References:
1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227, 3.3.5, SLES-15-450450060, 1.4.2, 1.4 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.icmp_echo_ignore_broadcasts from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.icmp_echo_ignore_broadcasts.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.icmp_echo_ignore_broadcasts" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_icmp_echo_ignore_broadcasts.conf'
sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value='1'
#
# Set runtime for net.ipv4.icmp_echo_ignore_broadcasts
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.icmp_echo_ignore_broadcasts="$sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value"
fi
#
# If net.ipv4.icmp_echo_ignore_broadcasts present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv4.icmp_echo_ignore_broadcasts = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.icmp_echo_ignore_broadcasts")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.icmp_echo_ignore_broadcasts\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.icmp_echo_ignore_broadcasts\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-91243-6"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91243-6
- CJIS-5.10.1.1
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_icmp_echo_ignore_broadcasts
- name: XCCDF Value sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value # promote to variable
set_fact:
sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value: !!str 1
tags:
- always
- name: Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces
- Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91243-6
- CJIS-5.10.1.1
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_icmp_echo_ignore_broadcasts
- name: Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces
- Find all files that contain net.ipv4.icmp_echo_ignore_broadcasts
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.icmp_echo_ignore_broadcasts\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91243-6
- CJIS-5.10.1.1
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_icmp_echo_ignore_broadcasts
- name: Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces
- Find all files that set net.ipv4.icmp_echo_ignore_broadcasts to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.icmp_echo_ignore_broadcasts\s*=\s*{{ sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91243-6
- CJIS-5.10.1.1
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_icmp_echo_ignore_broadcasts
- name: Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces
- Comment out any occurrences of net.ipv4.icmp_echo_ignore_broadcasts from config
files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.icmp_echo_ignore_broadcasts
replace: '#net.ipv4.icmp_echo_ignore_broadcasts'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-91243-6
- CJIS-5.10.1.1
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_icmp_echo_ignore_broadcasts
- name: Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces
- Comment out any occurrences of net.ipv4.icmp_echo_ignore_broadcasts from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.icmp_echo_ignore_broadcasts
replace: '#net.ipv4.icmp_echo_ignore_broadcasts'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91243-6
- CJIS-5.10.1.1
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_icmp_echo_ignore_broadcasts
- name: Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces
- Ensure sysctl net.ipv4.icmp_echo_ignore_broadcasts is set
ansible.posix.sysctl:
name: net.ipv4.icmp_echo_ignore_broadcasts
value: '{{ sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value }}'
sysctl_file: /etc/sysctl.d/net_ipv4_icmp_echo_ignore_broadcasts.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91243-6
- CJIS-5.10.1.1
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_icmp_echo_ignore_broadcasts
|
Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces
[ref]ruleTo set the runtime status of the net.ipv4.icmp_ignore_bogus_error_responses kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.icmp_ignore_bogus_error_responses = 1 Rationale:Ignoring bogus ICMP error responses reduces
log size, although some activity would not be logged. Identifiers:
CCE-91224-6 References:
1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, Req-1.4.3, SRG-OS-000480-GPOS-00227, 3.3.6, R12, SLES-15-450450045, 1.4.2, 1.4 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.icmp_ignore_bogus_error_responses from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.icmp_ignore_bogus_error_responses.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.icmp_ignore_bogus_error_responses" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_icmp_ignore_bogus_error_responses.conf'
sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value='1'
#
# Set runtime for net.ipv4.icmp_ignore_bogus_error_responses
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.icmp_ignore_bogus_error_responses="$sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value"
fi
#
# If net.ipv4.icmp_ignore_bogus_error_responses present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv4.icmp_ignore_bogus_error_responses = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.icmp_ignore_bogus_error_responses")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.icmp_ignore_bogus_error_responses\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.icmp_ignore_bogus_error_responses\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-91224-6"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91224-6
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_icmp_ignore_bogus_error_responses
- unknown_severity
- name: XCCDF Value sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value # promote to variable
set_fact:
sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value: !!str 1
tags:
- always
- name: Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces
- Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91224-6
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_icmp_ignore_bogus_error_responses
- unknown_severity
- name: Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces
- Find all files that contain net.ipv4.icmp_ignore_bogus_error_responses
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.icmp_ignore_bogus_error_responses\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91224-6
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_icmp_ignore_bogus_error_responses
- unknown_severity
- name: Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces
- Find all files that set net.ipv4.icmp_ignore_bogus_error_responses to correct
value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.icmp_ignore_bogus_error_responses\s*=\s*{{ sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91224-6
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_icmp_ignore_bogus_error_responses
- unknown_severity
- name: Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces
- Comment out any occurrences of net.ipv4.icmp_ignore_bogus_error_responses from
config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.icmp_ignore_bogus_error_responses
replace: '#net.ipv4.icmp_ignore_bogus_error_responses'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-91224-6
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_icmp_ignore_bogus_error_responses
- unknown_severity
- name: Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces
- Comment out any occurrences of net.ipv4.icmp_ignore_bogus_error_responses from
/etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.icmp_ignore_bogus_error_responses
replace: '#net.ipv4.icmp_ignore_bogus_error_responses'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91224-6
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_icmp_ignore_bogus_error_responses
- unknown_severity
- name: Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces
- Ensure sysctl net.ipv4.icmp_ignore_bogus_error_responses is set
ansible.posix.sysctl:
name: net.ipv4.icmp_ignore_bogus_error_responses
value: '{{ sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value }}'
sysctl_file: /etc/sysctl.d/net_ipv4_icmp_ignore_bogus_error_responses.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91224-6
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_icmp_ignore_bogus_error_responses
- unknown_severity
|
Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces
[ref]ruleTo set the runtime status of the net.ipv4.tcp_syncookies kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.tcp_syncookies=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.tcp_syncookies = 1 Rationale:A TCP SYN flood attack can cause a denial of service by filling a
system's TCP connection table with connections in the SYN_RCVD state.
Syncookies can be used to track a connection when a subsequent ACK is received,
verifying the initiator is attempting a valid connection and is not a flood
source. This feature is activated when a flood condition is detected, and
enables the system to continue servicing valid connection requests. Identifiers:
CCE-83283-2 References:
1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), SC-5(1), SC-5(2), SC-5(3)(a), CM-6(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4, Req-1.4.1, SRG-OS-000480-GPOS-00227, SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00071, SLES-15-010310, 3.3.8, R12, SLES-15-450450150, 1.4.3, 1.4, SV-234829r958528_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.tcp_syncookies from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.tcp_syncookies.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.tcp_syncookies" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_tcp_syncookies.conf'
sysctl_net_ipv4_tcp_syncookies_value='1'
#
# Set runtime for net.ipv4.tcp_syncookies
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.tcp_syncookies="$sysctl_net_ipv4_tcp_syncookies_value"
fi
#
# If net.ipv4.tcp_syncookies present in /etc/sysctl.conf, change value to appropriate value
# else, add "net.ipv4.tcp_syncookies = value" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.tcp_syncookies")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_tcp_syncookies_value"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.tcp_syncookies\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.tcp_syncookies\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-83283-2"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83283-2
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-010310
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(1)
- NIST-800-53-SC-5(2)
- NIST-800-53-SC-5(3)(a)
- PCI-DSS-Req-1.4.1
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_tcp_syncookies
- name: XCCDF Value sysctl_net_ipv4_tcp_syncookies_value # promote to variable
set_fact:
sysctl_net_ipv4_tcp_syncookies_value: !!str 1
tags:
- always
- name: Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces - Set
fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83283-2
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-010310
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(1)
- NIST-800-53-SC-5(2)
- NIST-800-53-SC-5(3)(a)
- PCI-DSS-Req-1.4.1
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_tcp_syncookies
- name: Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces - Find
all files that contain net.ipv4.tcp_syncookies
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.tcp_syncookies\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83283-2
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-010310
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(1)
- NIST-800-53-SC-5(2)
- NIST-800-53-SC-5(3)(a)
- PCI-DSS-Req-1.4.1
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_tcp_syncookies
- name: Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces - Find
all files that set net.ipv4.tcp_syncookies to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.tcp_syncookies\s*=\s*{{ sysctl_net_ipv4_tcp_syncookies_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83283-2
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-010310
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(1)
- NIST-800-53-SC-5(2)
- NIST-800-53-SC-5(3)(a)
- PCI-DSS-Req-1.4.1
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_tcp_syncookies
- name: Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces - Comment
out any occurrences of net.ipv4.tcp_syncookies from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.tcp_syncookies
replace: '#net.ipv4.tcp_syncookies'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-83283-2
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-010310
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(1)
- NIST-800-53-SC-5(2)
- NIST-800-53-SC-5(3)(a)
- PCI-DSS-Req-1.4.1
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_tcp_syncookies
- name: Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces - Comment
out any occurrences of net.ipv4.tcp_syncookies from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.tcp_syncookies
replace: '#net.ipv4.tcp_syncookies'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83283-2
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-010310
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(1)
- NIST-800-53-SC-5(2)
- NIST-800-53-SC-5(3)(a)
- PCI-DSS-Req-1.4.1
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_tcp_syncookies
- name: Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces - Ensure
sysctl net.ipv4.tcp_syncookies is set
ansible.posix.sysctl:
name: net.ipv4.tcp_syncookies
value: '{{ sysctl_net_ipv4_tcp_syncookies_value }}'
sysctl_file: /etc/sysctl.d/net_ipv4_tcp_syncookies.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83283-2
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-010310
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(1)
- NIST-800-53-SC-5(2)
- NIST-800-53-SC-5(3)(a)
- PCI-DSS-Req-1.4.1
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_tcp_syncookies
|
Network Parameters for Hosts Only
[ref]groupIf the system is not going to be used as a router, then setting certain
kernel parameters ensure that the host will not perform routing
of network traffic. |
| contains 3 rules |
Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
[ref]ruleTo set the runtime status of the net.ipv4.conf.all.send_redirects kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.all.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.all.send_redirects = 0 Rationale:ICMP redirect messages are used by routers to inform hosts that a more
direct route exists for a particular destination. These messages contain information
from the system's route table possibly revealing portions of the network topology.
The ability to send ICMP redirects is only appropriate for systems acting as routers. Identifiers:
CCE-85655-9 References:
1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, SLES-15-040370, 3.2.2, R12, SLES-15-450450030, 1.4.5, 1.4, SV-235023r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.conf.all.send_redirects from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.send_redirects.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.conf.all.send_redirects" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_conf_all_send_redirects.conf'
#
# Set runtime for net.ipv4.conf.all.send_redirects
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.conf.all.send_redirects="0"
fi
#
# If net.ipv4.conf.all.send_redirects present in /etc/sysctl.conf, change value to "0"
# else, add "net.ipv4.conf.all.send_redirects = 0" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.send_redirects")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.send_redirects\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.send_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-85655-9"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85655-9
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040370
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_send_redirects
- name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
- Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85655-9
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040370
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_send_redirects
- name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
- Find all files that contain net.ipv4.conf.all.send_redirects
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.send_redirects\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85655-9
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040370
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_send_redirects
- name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
- Find all files that set net.ipv4.conf.all.send_redirects to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.send_redirects\s*=\s*0$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85655-9
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040370
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_send_redirects
- name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
- Comment out any occurrences of net.ipv4.conf.all.send_redirects from config
files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.all.send_redirects
replace: '#net.ipv4.conf.all.send_redirects'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-85655-9
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040370
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_send_redirects
- name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
- Comment out any occurrences of net.ipv4.conf.all.send_redirects from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.conf.all.send_redirects
replace: '#net.ipv4.conf.all.send_redirects'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85655-9
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040370
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_send_redirects
- name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
- Ensure sysctl net.ipv4.conf.all.send_redirects is set to 0
ansible.posix.sysctl:
name: net.ipv4.conf.all.send_redirects
value: '0'
sysctl_file: /etc/sysctl.d/net_ipv4_conf_all_send_redirects.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85655-9
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040370
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_send_redirects
|
Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces by Default
[ref]ruleTo set the runtime status of the net.ipv4.conf.default.send_redirects kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.default.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.default.send_redirects = 0 Rationale:ICMP redirect messages are used by routers to inform hosts that a more
direct route exists for a particular destination. These messages contain information
from the system's route table possibly revealing portions of the network topology.
The ability to send ICMP redirects is only appropriate for systems acting as routers. Identifiers:
CCE-85654-2 References:
1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, SLES-15-040360, 3.2.2, R12, SLES-15-450450030, 1.4.5, 1.4, SV-235022r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.conf.default.send_redirects from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.send_redirects.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.conf.default.send_redirects" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_conf_default_send_redirects.conf'
#
# Set runtime for net.ipv4.conf.default.send_redirects
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.conf.default.send_redirects="0"
fi
#
# If net.ipv4.conf.default.send_redirects present in /etc/sysctl.conf, change value to "0"
# else, add "net.ipv4.conf.default.send_redirects = 0" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.send_redirects")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.send_redirects\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.send_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-85654-2"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85654-2
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040360
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_send_redirects
- name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
by Default - Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85654-2
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040360
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_send_redirects
- name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
by Default - Find all files that contain net.ipv4.conf.default.send_redirects
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.send_redirects\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85654-2
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040360
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_send_redirects
- name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
by Default - Find all files that set net.ipv4.conf.default.send_redirects to correct
value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.send_redirects\s*=\s*0$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85654-2
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040360
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_send_redirects
- name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
by Default - Comment out any occurrences of net.ipv4.conf.default.send_redirects
from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.default.send_redirects
replace: '#net.ipv4.conf.default.send_redirects'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-85654-2
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040360
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_send_redirects
- name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
by Default - Comment out any occurrences of net.ipv4.conf.default.send_redirects
from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.conf.default.send_redirects
replace: '#net.ipv4.conf.default.send_redirects'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85654-2
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040360
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_send_redirects
- name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
by Default - Ensure sysctl net.ipv4.conf.default.send_redirects is set to 0
ansible.posix.sysctl:
name: net.ipv4.conf.default.send_redirects
value: '0'
sysctl_file: /etc/sysctl.d/net_ipv4_conf_default_send_redirects.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85654-2
- CJIS-5.10.1.1
- DISA-STIG-SLES-15-040360
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_send_redirects
|
Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces
[ref]ruleTo set the runtime status of the net.ipv4.ip_forward kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.ip_forward=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.ip_forward = 0 Warning:
Certain technologies such as virtual machines, containers, etc. rely on IPv4 forwarding to enable and use networking.
Disabling IPv4 forwarding would cause those technologies to stop working. Therefore, this rule should not be used in
profiles or benchmarks that target usage of IPv4 forwarding. Rationale:Routing protocol daemons are typically used on routers to exchange
network topology information with other routers. If this capability is used when
not required, system network information may be unnecessarily transmitted across
the network. Identifiers:
CCE-85709-4 References:
1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-6(b), CM-6.1(iv), DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.3.1, Req-1.3.2, SRG-OS-000480-GPOS-00227, SLES-15-040380, 3.2.1, R12, SLES-15-450450015, 1.4.3, 1.4, SV-235024r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of net.ipv4.ip_forward from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.ip_forward.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "net.ipv4.ip_forward" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/net_ipv4_ip_forward.conf'
#
# Set runtime for net.ipv4.ip_forward
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w net.ipv4.ip_forward="0"
fi
#
# If net.ipv4.ip_forward present in /etc/sysctl.conf, change value to "0"
# else, add "net.ipv4.ip_forward = 0" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.ip_forward")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.ip_forward\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.ip_forward\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-85709-4"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85709-4
- DISA-STIG-SLES-15-040380
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSS-Req-1.3.1
- PCI-DSS-Req-1.3.2
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_ip_forward
- name: Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces - Set fact for
sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85709-4
- DISA-STIG-SLES-15-040380
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSS-Req-1.3.1
- PCI-DSS-Req-1.3.2
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_ip_forward
- name: Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces - Find all files
that contain net.ipv4.ip_forward
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.ip_forward\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85709-4
- DISA-STIG-SLES-15-040380
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSS-Req-1.3.1
- PCI-DSS-Req-1.3.2
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_ip_forward
- name: Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces - Find all files
that set net.ipv4.ip_forward to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.ip_forward\s*=\s*0$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85709-4
- DISA-STIG-SLES-15-040380
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSS-Req-1.3.1
- PCI-DSS-Req-1.3.2
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_ip_forward
- name: Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces - Comment out
any occurrences of net.ipv4.ip_forward from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.ip_forward
replace: '#net.ipv4.ip_forward'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-85709-4
- DISA-STIG-SLES-15-040380
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSS-Req-1.3.1
- PCI-DSS-Req-1.3.2
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_ip_forward
- name: Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces - Comment out
any occurrences of net.ipv4.ip_forward from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*net.ipv4.ip_forward
replace: '#net.ipv4.ip_forward'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85709-4
- DISA-STIG-SLES-15-040380
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSS-Req-1.3.1
- PCI-DSS-Req-1.3.2
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_ip_forward
- name: Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces - Ensure sysctl
net.ipv4.ip_forward is set to 0
ansible.posix.sysctl:
name: net.ipv4.ip_forward
value: '0'
sysctl_file: /etc/sysctl.d/net_ipv4_ip_forward.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85709-4
- DISA-STIG-SLES-15-040380
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSS-Req-1.3.1
- PCI-DSS-Req-1.3.2
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_ip_forward
|
nftables
[ref]groupIf firewalld or iptables are being used in your environment, please follow the guidance in their
respective section and pass-over the guidance in this section.
nftables is a subsystem of the Linux kernel providing filtering and classification of network
packets/datagrams/frames and is the successor to iptables. The biggest change with the
successor nftables is its simplicity. With iptables, we have to configure every single rule and
use the syntax which can be compared with normal commands. With nftables, the simpler
syntax, much like BPF (Berkely Packet Filter) means shorter lines and less repetition.
Support for nftables should also be compiled into the kernel, together with the related
nftables modules.
It is available in Linux kernels >= 3.13. Please ensure that your kernel
supports nftables before choosing this option.
|
| contains 3 rules |
Verify Group Who Owns /etc/nftables Directory
[ref]rule To properly set the group owner of /etc/nftables, run the command:
$ sudo chgrp root /etc/nftables
Rationale:The ownership of the /etc/nftables directory by the root group is important
because this directory hosts nftables configuration. Protection of this
directory is critical for system security. Assigning the ownership to root
ensures exclusive control of the nftables configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q nftables; then
newgroup=""
if getent group "root" >/dev/null 2>&1; then
newgroup="root"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "root is not a defined group on the system"
else
find -P /etc/nftables/ -maxdepth 0 -type d ! -group root -exec chgrp --no-dereference "$newgroup" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92500-8
- configure_strategy
- directory_groupowner_etc_nftables
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Check that the root group is defined
ansible.builtin.getent:
database: group
key: root
ignore_errors: true
when:
- '"nftables" in ansible_facts.packages'
- directory_groupowner_etc_nftables_newgroup is undefined
tags:
- CCE-92500-8
- configure_strategy
- directory_groupowner_etc_nftables
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the directory_groupowner_etc_nftables_newgroup variable if root found
ansible.builtin.set_fact:
directory_groupowner_etc_nftables_newgroup: root
when:
- '"nftables" in ansible_facts.packages'
- ansible_facts.getent_group["root"] is defined
tags:
- CCE-92500-8
- configure_strategy
- directory_groupowner_etc_nftables
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/nftables/
ansible.builtin.file:
path: /etc/nftables/
follow: false
state: directory
group: '{{ directory_groupowner_etc_nftables_newgroup }}'
when: '"nftables" in ansible_facts.packages'
tags:
- CCE-92500-8
- configure_strategy
- directory_groupowner_etc_nftables
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns /etc/nftables Directory
[ref]rule To properly set the owner of /etc/nftables, run the command:
$ sudo chown root /etc/nftables
Rationale:The ownership of the /etc/nftables directory by the root user is important
because this directory hosts nftables configuration. Protection of this
directory is critical for system security. Assigning the ownership to root
ensures exclusive control of the nftables configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q nftables; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
find -P /etc/nftables/ -maxdepth 0 -type d ! -user 0 -exec chown --no-dereference "$newown" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92509-9
- configure_strategy
- directory_owner_etc_nftables
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the directory_owner_etc_nftables_newown variable if represented by uid
ansible.builtin.set_fact:
directory_owner_etc_nftables_newown: '0'
when: '"nftables" in ansible_facts.packages'
tags:
- CCE-92509-9
- configure_strategy
- directory_owner_etc_nftables
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on directory /etc/nftables/
ansible.builtin.file:
path: /etc/nftables/
follow: false
state: directory
owner: '{{ directory_owner_etc_nftables_newown }}'
when: '"nftables" in ansible_facts.packages'
tags:
- CCE-92509-9
- configure_strategy
- directory_owner_etc_nftables
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions On /etc/nftables Directory
[ref]rule To properly set the permissions of /etc/nftables, run the command: $ sudo chmod 0700 /etc/nftables Rationale:Setting correct permissions on the /etc/nftables directory is important
because this directory hosts nftables configuration. Protection of this
directory is critical for system security. Restricting the permissions
ensures exclusive control of the nftables configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q nftables; then
find -H /etc/nftables/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92521-4
- configure_strategy
- directory_permissions_etc_nftables
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/nftables/ file(s)
ansible.builtin.command: 'find -P /etc/nftables/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type
d '
register: files_found
changed_when: false
failed_when: false
check_mode: false
when: '"nftables" in ansible_facts.packages'
tags:
- CCE-92521-4
- configure_strategy
- directory_permissions_etc_nftables
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set permissions for /etc/nftables/ file(s)
ansible.builtin.file:
path: '{{ item }}'
mode: u-s,g-xwrs,o-xwrt
state: directory
with_items:
- '{{ files_found.stdout_lines }}'
when: '"nftables" in ansible_facts.packages'
tags:
- CCE-92521-4
- configure_strategy
- directory_permissions_etc_nftables
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Uncommon Network Protocols
[ref]groupThe system includes support for several network protocols which are not commonly used.
Although security vulnerabilities in kernel networking code are not frequently discovered,
the consequences can be dramatic. Ensuring uncommon network protocols are disabled
reduces the system's risk to attacks targeted at its implementation of those protocols. Warning:
Although these protocols are not commonly used, avoid disruption
in your network environment by ensuring they are not needed
prior to disabling them. |
| contains 4 rules |
Disable DCCP Support
[ref]ruleThe Datagram Congestion Control Protocol (DCCP) is a
relatively new transport layer protocol, designed to support
streaming media and telephony.
To configure the system to prevent the dccp
kernel module from being loaded, add the following line to the file /etc/modprobe.d/dccp.conf:
install dccp /bin/false
This entry will cause a non-zero return value during a dccp module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install dccp /bin/true Rationale:Disabling DCCP protects
the system against exploitation of any flaws in its implementation. Identifiers:
CCE-91241-0 References:
11, 14, 3, 9, 5.10.1, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, Req-1.4.2, SRG-OS-000096-GPOS-00050, SRG-OS-000378-GPOS-00163, 3.4.1, SLES-15-450300015, 1.4.2, 1.4 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -q -m 1 "^install dccp" /etc/modprobe.d/dccp.conf ; then
sed -i 's#^install dccp.*#install dccp /bin/false#g' /etc/modprobe.d/dccp.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/dccp.conf
echo "install dccp /bin/false" >> /etc/modprobe.d/dccp.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist dccp$" /etc/modprobe.d/dccp.conf ; then
echo "blacklist dccp" >> /etc/modprobe.d/dccp.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91241-0
- CJIS-5.10.1
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-1.4.2
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- kernel_module_dccp_disabled
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- name: Ensure kernel module 'dccp' is disabled
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/dccp.conf
regexp: install\s+dccp
line: install dccp /bin/false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91241-0
- CJIS-5.10.1
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-1.4.2
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- kernel_module_dccp_disabled
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- name: Ensure kernel module 'dccp' is blacklisted
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/dccp.conf
regexp: ^blacklist dccp$
line: blacklist dccp
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91241-0
- CJIS-5.10.1
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-1.4.2
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- kernel_module_dccp_disabled
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
|
Disable RDS Support
[ref]ruleThe Reliable Datagram Sockets (RDS) protocol is a transport
layer protocol designed to provide reliable high-bandwidth,
low-latency communications between nodes in a cluster.
To configure the system to prevent the rds
kernel module from being loaded, add the following line to the file /etc/modprobe.d/rds.conf:
install rds /bin/false
This entry will cause a non-zero return value during a rds module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install rds /bin/true Rationale:Disabling RDS protects
the system against exploitation of any flaws in its implementation. Identifiers:
CCE-92580-0 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SLES-15-450300045 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -q -m 1 "^install rds" /etc/modprobe.d/rds.conf ; then
sed -i 's#^install rds.*#install rds /bin/false#g' /etc/modprobe.d/rds.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/rds.conf
echo "install rds /bin/false" >> /etc/modprobe.d/rds.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist rds$" /etc/modprobe.d/rds.conf ; then
echo "blacklist rds" >> /etc/modprobe.d/rds.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92580-0
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_rds_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'rds' is disabled
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/rds.conf
regexp: install\s+rds
line: install rds /bin/false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92580-0
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_rds_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'rds' is blacklisted
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/rds.conf
regexp: ^blacklist rds$
line: blacklist rds
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92580-0
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_rds_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
|
Disable SCTP Support
[ref]ruleThe Stream Control Transmission Protocol (SCTP) is a
transport layer protocol, designed to support the idea of
message-oriented communication, with several streams of messages
within one connection.
To configure the system to prevent the sctp
kernel module from being loaded, add the following line to the file /etc/modprobe.d/sctp.conf:
install sctp /bin/false
This entry will cause a non-zero return value during a sctp module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install sctp /bin/true Rationale:Disabling SCTP protects
the system against exploitation of any flaws in its implementation. Identifiers:
CCE-91242-8 References:
11, 14, 3, 9, 5.10.1, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, FMT_SMF_EXT.1, Req-1.4.2, SRG-OS-000095-GPOS-00049, SRG-OS-000480-GPOS-00227, 3.4.2, SLES-15-450300060, 1.4.2, 1.4 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -q -m 1 "^install sctp" /etc/modprobe.d/sctp.conf ; then
sed -i 's#^install sctp.*#install sctp /bin/false#g' /etc/modprobe.d/sctp.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/sctp.conf
echo "install sctp /bin/false" >> /etc/modprobe.d/sctp.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist sctp$" /etc/modprobe.d/sctp.conf ; then
echo "blacklist sctp" >> /etc/modprobe.d/sctp.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91242-8
- CJIS-5.10.1
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-1.4.2
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- kernel_module_sctp_disabled
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- name: Ensure kernel module 'sctp' is disabled
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/sctp.conf
regexp: install\s+sctp
line: install sctp /bin/false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91242-8
- CJIS-5.10.1
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-1.4.2
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- kernel_module_sctp_disabled
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- name: Ensure kernel module 'sctp' is blacklisted
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/sctp.conf
regexp: ^blacklist sctp$
line: blacklist sctp
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91242-8
- CJIS-5.10.1
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-1.4.2
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- kernel_module_sctp_disabled
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
|
Disable TIPC Support
[ref]ruleThe Transparent Inter-Process Communication (TIPC) protocol
is designed to provide communications between nodes in a
cluster.
To configure the system to prevent the tipc
kernel module from being loaded, add the following line to the file /etc/modprobe.d/tipc.conf:
install tipc /bin/false
This entry will cause a non-zero return value during a tipc module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install tipc /bin/true Warning:
This configuration baseline was created to deploy the base operating system for general purpose
workloads. When the operating system is configured for certain purposes, such as
a node in High Performance Computing cluster, it is expected that
the tipc kernel module will be loaded. Rationale:Disabling TIPC protects
the system against exploitation of any flaws in its implementation. Identifiers:
CCE-92581-8 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, FMT_SMF_EXT.1, SRG-OS-000095-GPOS-00049, SLES-15-450300030 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -q -m 1 "^install tipc" /etc/modprobe.d/tipc.conf ; then
sed -i 's#^install tipc.*#install tipc /bin/false#g' /etc/modprobe.d/tipc.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/tipc.conf
echo "install tipc /bin/false" >> /etc/modprobe.d/tipc.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist tipc$" /etc/modprobe.d/tipc.conf ; then
echo "blacklist tipc" >> /etc/modprobe.d/tipc.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92581-8
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_tipc_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'tipc' is disabled
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/tipc.conf
regexp: install\s+tipc
line: install tipc /bin/false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92581-8
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_tipc_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'tipc' is blacklisted
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/tipc.conf
regexp: ^blacklist tipc$
line: blacklist tipc
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92581-8
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_tipc_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
|
Wireless Networking
[ref]groupWireless networking, such as 802.11
(WiFi) and Bluetooth, can present a security risk to sensitive or
classified systems and networks. Wireless networking hardware is
much more likely to be included in laptop or portable systems than
in desktops or servers.
Removal of hardware provides the greatest assurance that the wireless
capability remains disabled. Acquisition policies often include provisions to
prevent the purchase of equipment that will be used in sensitive spaces and
includes wireless capabilities. If it is impractical to remove the wireless
hardware, and policy permits the device to enter sensitive spaces as long
as wireless is disabled, efforts should instead focus on disabling wireless capability
via software. |
| contains 2 rules |
Disable Wireless Through Software Configuration
[ref]groupIf it is impossible to remove the wireless hardware
from the device in question, disable as much of it as possible
through software. The following methods can disable software
support for wireless networking, but note that these methods do not
prevent malicious software or careless users from re-activating the
devices. |
| contains 2 rules |
Disable Bluetooth Service
[ref]rule
The bluetooth service can be disabled with the following command:
$ sudo systemctl mask --now bluetooth.service
$ sudo service bluetooth stop Rationale:Disabling the bluetooth service prevents the system from attempting
connections to Bluetooth devices, which entails some security risk.
Nevertheless, variation in this risk decision may be expected due to the
utility of Bluetooth connectivity and its limited range. Identifiers:
CCE-92600-6 References:
11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, 3.1.16, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, AC-18(a), AC-18(3), CM-7(a), CM-7(b), CM-6(a), MP-7, PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, SLES-15-450150045 Remediation script: (show)
[customizations.services]
masked = ["bluetooth"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_bluetooth
class disable_bluetooth {
service {'bluetooth':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'bluetooth.service'
fi
"$SYSTEMCTL_EXEC" disable 'bluetooth.service'
"$SYSTEMCTL_EXEC" mask 'bluetooth.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files bluetooth.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'bluetooth.socket'
fi
"$SYSTEMCTL_EXEC" mask 'bluetooth.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'bluetooth.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92600-6
- NIST-800-171-3.1.16
- NIST-800-53-AC-18(3)
- NIST-800-53-AC-18(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_bluetooth_disabled
- name: Disable Bluetooth Service - Disable service bluetooth
block:
- name: Disable Bluetooth Service - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable Bluetooth Service - Ensure bluetooth.service is Masked
ansible.builtin.systemd:
name: bluetooth.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("bluetooth.service", multiline=True)
- name: Unit Socket Exists - bluetooth.socket
ansible.builtin.command: systemctl -q list-unit-files bluetooth.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable Bluetooth Service - Disable Socket bluetooth
ansible.builtin.systemd:
name: bluetooth.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("bluetooth.socket", multiline=True)
tags:
- CCE-92600-6
- NIST-800-171-3.1.16
- NIST-800-53-AC-18(3)
- NIST-800-53-AC-18(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_bluetooth_disabled
- special_service_block
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
Deactivate Wireless Network Interfaces
[ref]ruleDeactivating wireless network interfaces should prevent normal usage of the wireless
capability.
Configure the system to disable wireless network interfaces by issuing the following
command for every active <WIFI-INTERFACE> in the system:
$ sudo wicked ifdown <WIFI-INTERFACE>
Also remove the configuration files for every wifi adapter from
/etc/wicked/ifconfig/<WIFI-INTERFACE>.xml to prevent future
connections.Rationale:The use of wireless networking can introduce many different attack vectors into
the organization's network. Common attack vectors such as malicious association
and ad hoc networks will allow an attacker to spoof a wireless access point
(AP), allowing validated systems to connect to the malicious AP and enabling the
attacker to monitor and record network traffic. These malicious APs can also
serve to create a man-in-the-middle attack or be used to create a denial of
service to valid network resources. Identifiers:
CCE-83286-5 References:
11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, 3.1.16, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, AC-18(a), AC-18(3), CM-7(a), CM-7(b), CM-6(a), MP-7, PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.3.3, SRG-OS-000299-GPOS-00117, SRG-OS-000300-GPOS-00118, SRG-OS-000424-GPOS-00188, SRG-OS-000481-GPOS-00481, SLES-15-010380, 3.1.2, SLES-15-450150030, 1315, 1319, 1.3.3, 1.3, SV-234847r991568_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ); then
zypper install -y "NetworkManager"
if command -v nmcli >/dev/null 2>&1 && systemctl is-active NetworkManager >/dev/null 2>&1; then
nmcli radio all off
fi
if command -v wicked >/dev/null 2>&1 && systemctl is-active wickedd >/dev/null 2>&1; then
if [ -n "$(find /sys/class/net/*/ -type d -name wireless)" ]; then
interfaces=$(find /sys/class/net/*/wireless -type d -name wireless | xargs -0 dirname | xargs basename)
for iface in $interfaces; do
wicked ifdown $iface
sed -i 's/STARTMODE=.*/STARTMODE=off/' /etc/sysconfig/network/ifcfg-$iface
done
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | unknown |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83286-5
- DISA-STIG-SLES-15-010380
- NIST-800-171-3.1.16
- NIST-800-53-AC-18(3)
- NIST-800-53-AC-18(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- PCI-DSS-Req-1.3.3
- PCI-DSSv4-1.3
- PCI-DSSv4-1.3.3
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- wireless_disable_interfaces
- name: Service facts
ansible.builtin.service_facts: null
when: ( not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman",
"container"] ) )
tags:
- CCE-83286-5
- DISA-STIG-SLES-15-010380
- NIST-800-171-3.1.16
- NIST-800-53-AC-18(3)
- NIST-800-53-AC-18(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- PCI-DSS-Req-1.3.3
- PCI-DSSv4-1.3
- PCI-DSSv4-1.3.3
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- wireless_disable_interfaces
- name: Wicked Deactivate Wireless Network Interfaces
ansible.builtin.command: wicked ifdown {{ item }}
loop: '{{ ansible_facts.interfaces }}'
when:
- ( not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
) )
- ansible_facts.services['wickedd.service'].state == 'running'
- item.startswith("wl")
tags:
- CCE-83286-5
- DISA-STIG-SLES-15-010380
- NIST-800-171-3.1.16
- NIST-800-53-AC-18(3)
- NIST-800-53-AC-18(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- PCI-DSS-Req-1.3.3
- PCI-DSSv4-1.3
- PCI-DSSv4-1.3.3
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- wireless_disable_interfaces
- name: Wicked Disable Wireless Network Interfaces
ansible.builtin.lineinfile:
path: /etc/sysconfig/network/ifcfg-{{ item }}
regexp: ^STARTMODE=
line: STARTMODE=off
loop: '{{ ansible_facts.interfaces }}'
when:
- ( not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
) )
- ansible_facts.services['wickedd.service'].state == 'running'
- item.startswith("wl")
tags:
- CCE-83286-5
- DISA-STIG-SLES-15-010380
- NIST-800-171-3.1.16
- NIST-800-53-AC-18(3)
- NIST-800-53-AC-18(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- PCI-DSS-Req-1.3.3
- PCI-DSSv4-1.3
- PCI-DSSv4-1.3.3
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- wireless_disable_interfaces
- name: NetworkManager Deactivate Wireless Network Interfaces
ansible.builtin.command: nmcli radio wifi off
when:
- ( not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
) )
- '''NetworkManager'' in ansible_facts.packages'
- ansible_facts.services['NetworkManager.service'].state == 'running'
tags:
- CCE-83286-5
- DISA-STIG-SLES-15-010380
- NIST-800-171-3.1.16
- NIST-800-53-AC-18(3)
- NIST-800-53-AC-18(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- PCI-DSS-Req-1.3.3
- PCI-DSSv4-1.3
- PCI-DSSv4-1.3.3
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
- wireless_disable_interfaces
|
File Permissions and Masks
[ref]groupTraditional Unix security relies heavily on file and
directory permissions to prevent unauthorized users from reading or
modifying files to which they should not have access.
Several of the commands in this section search filesystems
for files or directories with certain characteristics, and are
intended to be run on every local partition on a given system.
When the variable PART appears in one of the commands below,
it means that the command is intended to be run repeatedly, with the
name of each local partition substituted for PART in turn.
The following command prints a list of all xfs partitions on the local
system, which is the default filesystem for SUSE Linux Enterprise 15
installations:
$ mount -t xfs | awk '{print $3}'
For any systems that use a different
local filesystem type, modify this command as appropriate. |
| contains 76 rules |
Verify Permissions on Important Files and
Directories
[ref]groupPermissions for many files on a system must be set
restrictively to ensure sensitive information is properly protected.
This section discusses important
permission restrictions which can be verified
to ensure that no harmful discrepancies have
arisen. |
| contains 41 rules |
Verify Permissions on Files with Local Account Information and Credentials
[ref]groupThe default restrictive permissions for files which act as
important security databases such as passwd, shadow,
group, and gshadow files must be maintained. Many utilities
need read access to the passwd file in order to function properly, but
read access to the shadow file allows malicious attacks against system
passwords, and should never be enabled. |
| contains 33 rules |
Verify Group Who Owns Backup group File
[ref]rule To properly set the group owner of /etc/group-, run the command:
$ sudo chgrp root /etc/group-
Rationale:The /etc/group- file is a backup file of /etc/group, and as such,
it contains information regarding groups that are configured on the system.
Protection of this file is important for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/group-" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/group-
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_groupowner_backup_etc_group_newgroup variable if represented
by gid
ansible.builtin.set_fact:
file_groupowner_backup_etc_group_newgroup: '0'
tags:
- CCE-91329-3
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_backup_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/group-
ansible.builtin.stat:
path: /etc/group-
register: file_exists
tags:
- CCE-91329-3
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_backup_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/group-
ansible.builtin.file:
path: /etc/group-
follow: false
group: '{{ file_groupowner_backup_etc_group_newgroup }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91329-3
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_backup_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns Backup gshadow File
[ref]rule To properly set the group owner of /etc/gshadow-, run the command:
$ sudo chgrp root /etc/gshadow-
Rationale:The /etc/gshadow- file is a backup of /etc/gshadow, and as such,
it contains group password hashes. Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/gshadow-" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/gshadow-
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_groupowner_backup_etc_gshadow_newgroup variable if represented
by gid
ansible.builtin.set_fact:
file_groupowner_backup_etc_gshadow_newgroup: '0'
tags:
- CCE-92698-0
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7
- configure_strategy
- file_groupowner_backup_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/gshadow-
ansible.builtin.stat:
path: /etc/gshadow-
register: file_exists
tags:
- CCE-92698-0
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7
- configure_strategy
- file_groupowner_backup_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/gshadow-
ansible.builtin.file:
path: /etc/gshadow-
follow: false
group: '{{ file_groupowner_backup_etc_gshadow_newgroup }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92698-0
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7
- configure_strategy
- file_groupowner_backup_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns Backup passwd File
[ref]rule To properly set the group owner of /etc/passwd-, run the command:
$ sudo chgrp root /etc/passwd-
Rationale:The /etc/passwd- file is a backup file of /etc/passwd, and as such,
it contains information about the users that are configured on the system.
Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/passwd-" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/passwd-
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_groupowner_backup_etc_passwd_newgroup variable if represented
by gid
ansible.builtin.set_fact:
file_groupowner_backup_etc_passwd_newgroup: '0'
tags:
- CCE-91323-6
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_backup_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/passwd-
ansible.builtin.stat:
path: /etc/passwd-
register: file_exists
tags:
- CCE-91323-6
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_backup_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/passwd-
ansible.builtin.file:
path: /etc/passwd-
follow: false
group: '{{ file_groupowner_backup_etc_passwd_newgroup }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91323-6
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_backup_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns Backup shadow File
[ref]rule To properly set the group owner of /etc/shadow-, run the command:
$ sudo chgrp shadow /etc/shadow-
Rationale:The /etc/shadow- file is a backup file of /etc/shadow, and as such,
it contains the list of local system accounts and password hashes.
Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newgroup=""
if getent group "15" >/dev/null 2>&1; then
newgroup="15"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "15 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/shadow-" | grep -E -w -q "15"; then
chgrp --no-dereference "$newgroup" /etc/shadow-
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_groupowner_backup_etc_shadow_newgroup variable if represented
by gid
ansible.builtin.set_fact:
file_groupowner_backup_etc_shadow_newgroup: '15'
tags:
- CCE-91327-7
- PCI-DSS-Req-8.7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_backup_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/shadow-
ansible.builtin.stat:
path: /etc/shadow-
register: file_exists
tags:
- CCE-91327-7
- PCI-DSS-Req-8.7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_backup_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/shadow-
ansible.builtin.file:
path: /etc/shadow-
follow: false
group: '{{ file_groupowner_backup_etc_shadow_newgroup }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91327-7
- PCI-DSS-Req-8.7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_backup_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns group File
[ref]rule To properly set the group owner of /etc/group, run the command:
$ sudo chgrp root /etc/group
Rationale:The /etc/group file contains information regarding groups that are configured
on the system. Protection of this file is important for system security. Identifiers:
CCE-85801-9 References:
12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.4, R50, SLES-15-900150045, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/group" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/group
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_groupowner_etc_group_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_etc_group_newgroup: '0'
tags:
- CCE-85801-9
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/group
ansible.builtin.stat:
path: /etc/group
register: file_exists
tags:
- CCE-85801-9
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/group
ansible.builtin.file:
path: /etc/group
follow: false
group: '{{ file_groupowner_etc_group_newgroup }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-85801-9
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns gshadow File
[ref]rule To properly set the group owner of /etc/gshadow, run the command:
$ sudo chgrp root /etc/gshadow
Rationale:The /etc/gshadow file contains group password hashes. Protection of this file
is critical for system security. Identifiers:
CCE-91348-3 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 6.1.2, R50, SLES-15-900150015, SLES-15-900150105 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/gshadow" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/gshadow
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_groupowner_etc_gshadow_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_etc_gshadow_newgroup: '0'
tags:
- CCE-91348-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_groupowner_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/gshadow
ansible.builtin.stat:
path: /etc/gshadow
register: file_exists
tags:
- CCE-91348-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_groupowner_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/gshadow
ansible.builtin.file:
path: /etc/gshadow
follow: false
group: '{{ file_groupowner_etc_gshadow_newgroup }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91348-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_groupowner_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns passwd File
[ref]rule To properly set the group owner of /etc/passwd, run the command:
$ sudo chgrp root /etc/passwd
Rationale:The /etc/passwd file contains information about the users that are configured on
the system. Protection of this file is critical for system security. Identifiers:
CCE-85809-2 References:
12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.2, R50, SLES-15-900150015, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/passwd" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/passwd
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_groupowner_etc_passwd_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_etc_passwd_newgroup: '0'
tags:
- CCE-85809-2
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/passwd
ansible.builtin.stat:
path: /etc/passwd
register: file_exists
tags:
- CCE-85809-2
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/passwd
ansible.builtin.file:
path: /etc/passwd
follow: false
group: '{{ file_groupowner_etc_passwd_newgroup }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-85809-2
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns /etc/security/opasswd File
[ref]rule To properly set the group owner of /etc/security/opasswd, run the command:
$ sudo chgrp root /etc/security/opasswd
Rationale:The /etc/security/opasswd file stores old passwords to prevent
password reuse. Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/security/opasswd" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/security/opasswd
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_groupowner_etc_security_opasswd_newgroup variable if represented
by gid
ansible.builtin.set_fact:
file_groupowner_etc_security_opasswd_newgroup: '0'
tags:
- CCE-92539-6
- configure_strategy
- file_groupowner_etc_security_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/security/opasswd
ansible.builtin.stat:
path: /etc/security/opasswd
register: file_exists
tags:
- CCE-92539-6
- configure_strategy
- file_groupowner_etc_security_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/security/opasswd
ansible.builtin.file:
path: /etc/security/opasswd
follow: false
group: '{{ file_groupowner_etc_security_opasswd_newgroup }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92539-6
- configure_strategy
- file_groupowner_etc_security_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns /etc/security/opasswd.old File
[ref]rule To properly set the group owner of /etc/security/opasswd.old, run the command:
$ sudo chgrp root /etc/security/opasswd.old
Rationale:The /etc/security/opasswd.old file stores backups of old passwords to prevent
password reuse. Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/security/opasswd.old" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/security/opasswd.old
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_groupowner_etc_security_opasswd_old_newgroup variable if represented
by gid
ansible.builtin.set_fact:
file_groupowner_etc_security_opasswd_old_newgroup: '0'
tags:
- CCE-92540-4
- configure_strategy
- file_groupowner_etc_security_opasswd_old
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/security/opasswd.old
ansible.builtin.stat:
path: /etc/security/opasswd.old
register: file_exists
tags:
- CCE-92540-4
- configure_strategy
- file_groupowner_etc_security_opasswd_old
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/security/opasswd.old
ansible.builtin.file:
path: /etc/security/opasswd.old
follow: false
group: '{{ file_groupowner_etc_security_opasswd_old_newgroup }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92540-4
- configure_strategy
- file_groupowner_etc_security_opasswd_old
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns shadow File
[ref]rule To properly set the group owner of /etc/shadow, run the command:
$ sudo chgrp shadow /etc/shadow
Rationale:The /etc/shadow file stores password hashes. Protection of this file is
critical for system security. Identifiers:
CCE-85808-4 References:
12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.3, R50, SLES-15-900150075, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newgroup=""
if getent group "15" >/dev/null 2>&1; then
newgroup="15"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "15 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/shadow" | grep -E -w -q "15"; then
chgrp --no-dereference "$newgroup" /etc/shadow
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_groupowner_etc_shadow_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_etc_shadow_newgroup: '15'
tags:
- CCE-85808-4
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/shadow
ansible.builtin.stat:
path: /etc/shadow
register: file_exists
tags:
- CCE-85808-4
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/shadow
ansible.builtin.file:
path: /etc/shadow
follow: false
group: '{{ file_groupowner_etc_shadow_newgroup }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-85808-4
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns /etc/shells File
[ref]rule
To properly set the group owner of /etc/shells, run the command:
$ sudo chgrp root /etc/shells
Rationale:The /etc/shells file contains the list of full pathnames to shells on the system.
Since this file is used by many system programs this file should be protected. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/shells" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/shells
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_groupowner_etc_shells_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_etc_shells_newgroup: '0'
tags:
- CCE-92541-2
- NIST-800-53-AC-3
- NIST-800-53-MP-2
- configure_strategy
- file_groupowner_etc_shells
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/shells
ansible.builtin.stat:
path: /etc/shells
register: file_exists
tags:
- CCE-92541-2
- NIST-800-53-AC-3
- NIST-800-53-MP-2
- configure_strategy
- file_groupowner_etc_shells
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/shells
ansible.builtin.file:
path: /etc/shells
follow: false
group: '{{ file_groupowner_etc_shells_newgroup }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92541-2
- NIST-800-53-AC-3
- NIST-800-53-MP-2
- configure_strategy
- file_groupowner_etc_shells
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns Backup group File
[ref]rule To properly set the owner of /etc/group-, run the command:
$ sudo chown root /etc/group-
Rationale:The /etc/group- file is a backup file of /etc/group, and as such,
it contains information regarding groups that are configured on the system.
Protection of this file is important for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/group-" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/group-
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_owner_backup_etc_group_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_backup_etc_group_newown: '0'
tags:
- CCE-91330-1
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_backup_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/group-
ansible.builtin.stat:
path: /etc/group-
register: file_exists
tags:
- CCE-91330-1
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_backup_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/group-
ansible.builtin.file:
path: /etc/group-
follow: false
owner: '{{ file_owner_backup_etc_group_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91330-1
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_backup_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns Backup gshadow File
[ref]rule To properly set the owner of /etc/gshadow-, run the command:
$ sudo chown root /etc/gshadow-
Rationale:The /etc/gshadow- file is a backup of /etc/gshadow, and as such,
it contains group password hashes. Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/gshadow-" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/gshadow-
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_owner_backup_etc_gshadow_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_backup_etc_gshadow_newown: '0'
tags:
- CCE-92699-8
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7
- configure_strategy
- file_owner_backup_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/gshadow-
ansible.builtin.stat:
path: /etc/gshadow-
register: file_exists
tags:
- CCE-92699-8
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7
- configure_strategy
- file_owner_backup_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/gshadow-
ansible.builtin.file:
path: /etc/gshadow-
follow: false
owner: '{{ file_owner_backup_etc_gshadow_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92699-8
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7
- configure_strategy
- file_owner_backup_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns Backup passwd File
[ref]rule To properly set the owner of /etc/passwd-, run the command:
$ sudo chown root /etc/passwd-
Rationale:The /etc/passwd- file is a backup file of /etc/passwd, and as such,
it contains information about the users that are configured on the system.
Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/passwd-" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/passwd-
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_owner_backup_etc_passwd_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_backup_etc_passwd_newown: '0'
tags:
- CCE-91324-4
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_backup_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/passwd-
ansible.builtin.stat:
path: /etc/passwd-
register: file_exists
tags:
- CCE-91324-4
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_backup_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/passwd-
ansible.builtin.file:
path: /etc/passwd-
follow: false
owner: '{{ file_owner_backup_etc_passwd_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91324-4
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_backup_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns Backup shadow File
[ref]rule To properly set the owner of /etc/shadow-, run the command:
$ sudo chown root /etc/shadow-
Rationale:The /etc/shadow- file is a backup file of /etc/shadow, and as such,
it contains the list of local system accounts and password hashes.
Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/shadow-" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/shadow-
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_owner_backup_etc_shadow_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_backup_etc_shadow_newown: '0'
tags:
- CCE-91326-9
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_backup_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/shadow-
ansible.builtin.stat:
path: /etc/shadow-
register: file_exists
tags:
- CCE-91326-9
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_backup_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/shadow-
ansible.builtin.file:
path: /etc/shadow-
follow: false
owner: '{{ file_owner_backup_etc_shadow_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91326-9
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_backup_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns group File
[ref]rule To properly set the owner of /etc/group, run the command:
$ sudo chown root /etc/group
Rationale:The /etc/group file contains information regarding groups that are configured
on the system. Protection of this file is important for system security. Identifiers:
CCE-85802-7 References:
12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.4, R50, SLES-15-900150045, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/group" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/group
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_owner_etc_group_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_etc_group_newown: '0'
tags:
- CCE-85802-7
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/group
ansible.builtin.stat:
path: /etc/group
register: file_exists
tags:
- CCE-85802-7
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/group
ansible.builtin.file:
path: /etc/group
follow: false
owner: '{{ file_owner_etc_group_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-85802-7
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns gshadow File
[ref]rule To properly set the owner of /etc/gshadow, run the command:
$ sudo chown root /etc/gshadow
Rationale:The /etc/gshadow file contains group password hashes. Protection of this file
is critical for system security. Identifiers:
CCE-91230-3 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 6.1.2, R50, SLES-15-900150015, SLES-15-900150105 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/gshadow" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/gshadow
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_owner_etc_gshadow_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_etc_gshadow_newown: '0'
tags:
- CCE-91230-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_owner_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/gshadow
ansible.builtin.stat:
path: /etc/gshadow
register: file_exists
tags:
- CCE-91230-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_owner_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/gshadow
ansible.builtin.file:
path: /etc/gshadow
follow: false
owner: '{{ file_owner_etc_gshadow_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91230-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_owner_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns passwd File
[ref]rule To properly set the owner of /etc/passwd, run the command:
$ sudo chown root /etc/passwd
Rationale:The /etc/passwd file contains information about the users that are configured on
the system. Protection of this file is critical for system security. Identifiers:
CCE-85806-8 References:
12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.2, R50, SLES-15-900150015, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/passwd" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/passwd
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_owner_etc_passwd_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_etc_passwd_newown: '0'
tags:
- CCE-85806-8
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/passwd
ansible.builtin.stat:
path: /etc/passwd
register: file_exists
tags:
- CCE-85806-8
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/passwd
ansible.builtin.file:
path: /etc/passwd
follow: false
owner: '{{ file_owner_etc_passwd_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-85806-8
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns /etc/security/opasswd File
[ref]rule To properly set the owner of /etc/security/opasswd, run the command:
$ sudo chown root /etc/security/opasswd
Rationale:The /etc/security/opasswd file stores old passwords to prevent
password reuse. Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/security/opasswd" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/security/opasswd
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_owner_etc_security_opasswd_newown variable if represented by
uid
ansible.builtin.set_fact:
file_owner_etc_security_opasswd_newown: '0'
tags:
- CCE-92545-3
- configure_strategy
- file_owner_etc_security_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/security/opasswd
ansible.builtin.stat:
path: /etc/security/opasswd
register: file_exists
tags:
- CCE-92545-3
- configure_strategy
- file_owner_etc_security_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/security/opasswd
ansible.builtin.file:
path: /etc/security/opasswd
follow: false
owner: '{{ file_owner_etc_security_opasswd_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92545-3
- configure_strategy
- file_owner_etc_security_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns /etc/security/opasswd.old File
[ref]rule To properly set the owner of /etc/security/opasswd.old, run the command:
$ sudo chown root /etc/security/opasswd.old
Rationale:The /etc/security/opasswd.old file stores backups of old passwords to prevent
password reuse. Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/security/opasswd.old" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/security/opasswd.old
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_owner_etc_security_opasswd_old_newown variable if represented
by uid
ansible.builtin.set_fact:
file_owner_etc_security_opasswd_old_newown: '0'
tags:
- CCE-92546-1
- configure_strategy
- file_owner_etc_security_opasswd_old
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/security/opasswd.old
ansible.builtin.stat:
path: /etc/security/opasswd.old
register: file_exists
tags:
- CCE-92546-1
- configure_strategy
- file_owner_etc_security_opasswd_old
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/security/opasswd.old
ansible.builtin.file:
path: /etc/security/opasswd.old
follow: false
owner: '{{ file_owner_etc_security_opasswd_old_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92546-1
- configure_strategy
- file_owner_etc_security_opasswd_old
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns shadow File
[ref]rule To properly set the owner of /etc/shadow, run the command:
$ sudo chown root /etc/shadow
Rationale:The /etc/shadow file contains the list of local
system accounts and stores password hashes. Protection of this file is
critical for system security. Failure to give ownership of this file
to root provides the designated owner with access to sensitive information
which could weaken the system security posture. Identifiers:
CCE-85807-6 References:
12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.3, R50, SLES-15-900150075, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/shadow" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/shadow
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_owner_etc_shadow_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_etc_shadow_newown: '0'
tags:
- CCE-85807-6
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/shadow
ansible.builtin.stat:
path: /etc/shadow
register: file_exists
tags:
- CCE-85807-6
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/shadow
ansible.builtin.file:
path: /etc/shadow
follow: false
owner: '{{ file_owner_etc_shadow_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-85807-6
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Who Owns /etc/shells File
[ref]rule
To properly set the owner of /etc/shells, run the command:
$ sudo chown root /etc/shells
Rationale:The /etc/shells file contains the list of full pathnames to shells on the system.
Since this file is used by many system programs this file should be protected. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/shells" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/shells
fi
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Set the file_owner_etc_shells_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_etc_shells_newown: '0'
tags:
- CCE-92547-9
- NIST-800-53-AC-3
- NIST-800-53-MP-2
- configure_strategy
- file_owner_etc_shells
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/shells
ansible.builtin.stat:
path: /etc/shells
register: file_exists
tags:
- CCE-92547-9
- NIST-800-53-AC-3
- NIST-800-53-MP-2
- configure_strategy
- file_owner_etc_shells
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/shells
ansible.builtin.file:
path: /etc/shells
follow: false
owner: '{{ file_owner_etc_shells_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92547-9
- NIST-800-53-AC-3
- NIST-800-53-MP-2
- configure_strategy
- file_owner_etc_shells
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on Backup group File
[ref]rule
To properly set the permissions of /etc/group-, run the command:
$ sudo chmod 0644 /etc/group- Rationale:The /etc/group- file is a backup file of /etc/group, and as such,
it contains information regarding groups that are configured on the system.
Protection of this file is important for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/group-
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Test for existence /etc/group-
ansible.builtin.stat:
path: /etc/group-
register: file_exists
tags:
- CCE-91331-9
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_backup_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xws,o-xwt on /etc/group-
ansible.builtin.file:
path: /etc/group-
mode: u-xs,g-xws,o-xwt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91331-9
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_backup_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on Backup gshadow File
[ref]rule
To properly set the permissions of /etc/gshadow-, run the command:
$ sudo chmod 0000 /etc/gshadow- Rationale:The /etc/gshadow- file is a backup of /etc/gshadow, and as such,
it contains group password hashes. Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xwrs,g-xwrs,o-xwrt /etc/gshadow-
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Test for existence /etc/gshadow-
ansible.builtin.stat:
path: /etc/gshadow-
register: file_exists
tags:
- CCE-92700-4
- NIST-800-53-AC-6 (1)
- configure_strategy
- file_permissions_backup_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xwrs,g-xwrs,o-xwrt on /etc/gshadow-
ansible.builtin.file:
path: /etc/gshadow-
mode: u-xwrs,g-xwrs,o-xwrt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92700-4
- NIST-800-53-AC-6 (1)
- configure_strategy
- file_permissions_backup_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on Backup passwd File
[ref]rule
To properly set the permissions of /etc/passwd-, run the command:
$ sudo chmod 0644 /etc/passwd- Rationale:The /etc/passwd- file is a backup file of /etc/passwd, and as such,
it contains information about the users that are configured on the system.
Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/passwd-
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Test for existence /etc/passwd-
ansible.builtin.stat:
path: /etc/passwd-
register: file_exists
tags:
- CCE-91325-1
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_backup_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xws,o-xwt on /etc/passwd-
ansible.builtin.file:
path: /etc/passwd-
mode: u-xs,g-xws,o-xwt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91325-1
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_backup_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on Backup shadow File
[ref]rule
To properly set the permissions of /etc/shadow-, run the command:
$ sudo chmod 0640 /etc/shadow- Rationale:The /etc/shadow- file is a backup file of /etc/shadow, and as such,
it contains the list of local system accounts and password hashes.
Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwrt /etc/shadow-
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Test for existence /etc/shadow-
ansible.builtin.stat:
path: /etc/shadow-
register: file_exists
tags:
- CCE-91328-5
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_backup_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xws,o-xwrt on /etc/shadow-
ansible.builtin.file:
path: /etc/shadow-
mode: u-xs,g-xws,o-xwrt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91328-5
- NIST-800-53-AC-6 (1)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_backup_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on group File
[ref]rule
To properly set the permissions of /etc/group, run the command:
$ sudo chmod 0644 /etc/group Rationale:The /etc/group file contains information regarding groups that are configured
on the system. Protection of this file is important for system security. Identifiers:
CCE-85803-5 References:
12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.4, R50, SLES-15-900150045, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/group
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Test for existence /etc/group
ansible.builtin.stat:
path: /etc/group
register: file_exists
tags:
- CCE-85803-5
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xws,o-xwt on /etc/group
ansible.builtin.file:
path: /etc/group
mode: u-xs,g-xws,o-xwt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-85803-5
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_etc_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on gshadow File
[ref]rule
To properly set the permissions of /etc/gshadow, run the command:
$ sudo chmod 0000 /etc/gshadow Rationale:The /etc/gshadow file contains group password hashes. Protection of this file
is critical for system security. Identifiers:
CCE-91231-1 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 6.1.2, R50, SLES-15-900150015, SLES-15-900150105 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xwrs,g-xwrs,o-xwrt /etc/gshadow
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Test for existence /etc/gshadow
ansible.builtin.stat:
path: /etc/gshadow
register: file_exists
tags:
- CCE-91231-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_permissions_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xwrs,g-xwrs,o-xwrt on /etc/gshadow
ansible.builtin.file:
path: /etc/gshadow
mode: u-xwrs,g-xwrs,o-xwrt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91231-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_permissions_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on passwd File
[ref]rule
To properly set the permissions of /etc/passwd, run the command:
$ sudo chmod 0644 /etc/passwd Rationale:If the /etc/passwd file is writable by a group-owner or the
world the risk of its compromise is increased. The file contains the list of
accounts on the system and associated information, and protection of this file
is critical for system security. Identifiers:
CCE-85805-0 References:
12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.2, R50, SLES-15-900150015, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/passwd
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Test for existence /etc/passwd
ansible.builtin.stat:
path: /etc/passwd
register: file_exists
tags:
- CCE-85805-0
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xws,o-xwt on /etc/passwd
ansible.builtin.file:
path: /etc/passwd
mode: u-xs,g-xws,o-xwt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-85805-0
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_etc_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on /etc/security/opasswd File
[ref]rule
To properly set the permissions of /etc/security/opasswd, run the command:
$ sudo chmod 0600 /etc/security/opasswd Rationale:The /etc/security/opasswd file stores old passwords to prevent
password reuse. Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xwrs,o-xwrt /etc/security/opasswd
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Test for existence /etc/security/opasswd
ansible.builtin.stat:
path: /etc/security/opasswd
register: file_exists
tags:
- CCE-92558-6
- configure_strategy
- file_permissions_etc_security_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xwrs,o-xwrt on /etc/security/opasswd
ansible.builtin.file:
path: /etc/security/opasswd
mode: u-xs,g-xwrs,o-xwrt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92558-6
- configure_strategy
- file_permissions_etc_security_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on /etc/security/opasswd.old File
[ref]rule
To properly set the permissions of /etc/security/opasswd.old, run the command:
$ sudo chmod 0600 /etc/security/opasswd.old Rationale:The /etc/security/opasswd.old file stores backups of old passwords to prevent
password reuse. Protection of this file is critical for system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xwrs,o-xwrt /etc/security/opasswd.old
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Test for existence /etc/security/opasswd.old
ansible.builtin.stat:
path: /etc/security/opasswd.old
register: file_exists
tags:
- CCE-92559-4
- configure_strategy
- file_permissions_etc_security_opasswd_old
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xwrs,o-xwrt on /etc/security/opasswd.old
ansible.builtin.file:
path: /etc/security/opasswd.old
mode: u-xs,g-xwrs,o-xwrt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92559-4
- configure_strategy
- file_permissions_etc_security_opasswd_old
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on shadow File
[ref]rule
To properly set the permissions of /etc/shadow, run the command:
$ sudo chmod 0640 /etc/shadow Rationale:The /etc/shadow file contains the list of local
system accounts and stores password hashes. Protection of this file is
critical for system security. Failure to give ownership of this file
to root provides the designated owner with access to sensitive information
which could weaken the system security posture. Identifiers:
CCE-85804-3 References:
12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.3, R50, SLES-15-900150075, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwrt /etc/shadow
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Test for existence /etc/shadow
ansible.builtin.stat:
path: /etc/shadow
register: file_exists
tags:
- CCE-85804-3
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xws,o-xwrt on /etc/shadow
ansible.builtin.file:
path: /etc/shadow
mode: u-xs,g-xws,o-xwrt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-85804-3
- CJIS-5.5.2.2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-8.7.c
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_etc_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on /etc/shells File
[ref]rule
To properly set the permissions of /etc/shells, run the command:
$ sudo chmod 0644 /etc/shells Rationale:The /etc/shells file contains the list of full pathnames to shells on the system.
Since this file is used by many system programs this file should be protected. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/shells
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Test for existence /etc/shells
ansible.builtin.stat:
path: /etc/shells
register: file_exists
tags:
- CCE-92562-8
- NIST-800-53-AC-3
- NIST-800-53-MP-2
- configure_strategy
- file_permissions_etc_shells
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xws,o-xwt on /etc/shells
ansible.builtin.file:
path: /etc/shells
mode: u-xs,g-xws,o-xwt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92562-8
- NIST-800-53-AC-3
- NIST-800-53-MP-2
- configure_strategy
- file_permissions_etc_shells
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify File Permissions Within Some Important Directories
[ref]groupSome directories contain files whose confidentiality or integrity
is notably important and may also be susceptible to misconfiguration over time, particularly if
unpackaged software is installed. As such,
an argument exists to verify that files' permissions within these directories remain
configured correctly and restrictively. |
| contains 3 rules |
Verify Group Who Owns /etc/sysctl.d Directory
[ref]rule To properly set the group owner of /etc/sysctl.d, run the command:
$ sudo chgrp root /etc/sysctl.d
Rationale:The ownership of the /etc/sysctl.d directory by the root group is important
because this directory hosts kernel configuration. Protection of this
directory is critical for system security. Assigning the ownership to root
ensures exclusive control of the kernel configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newgroup=""
if getent group "root" >/dev/null 2>&1; then
newgroup="root"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "root is not a defined group on the system"
else
find -P /etc/sysctl.d/ -maxdepth 0 -type d ! -group root -exec chgrp --no-dereference "$newgroup" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92506-5
- configure_strategy
- directory_groupowner_etc_sysctld
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Check that the root group is defined
ansible.builtin.getent:
database: group
key: root
ignore_errors: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- directory_groupowner_etc_sysctld_newgroup is undefined
tags:
- CCE-92506-5
- configure_strategy
- directory_groupowner_etc_sysctld
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the directory_groupowner_etc_sysctld_newgroup variable if root found
ansible.builtin.set_fact:
directory_groupowner_etc_sysctld_newgroup: root
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_facts.getent_group["root"] is defined
tags:
- CCE-92506-5
- configure_strategy
- directory_groupowner_etc_sysctld
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/sysctl.d/
ansible.builtin.file:
path: /etc/sysctl.d/
follow: false
state: directory
group: '{{ directory_groupowner_etc_sysctld_newgroup }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92506-5
- configure_strategy
- directory_groupowner_etc_sysctld
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns /etc/sysctl.d Directory
[ref]rule To properly set the owner of /etc/sysctl.d, run the command:
$ sudo chown root /etc/sysctl.d
Rationale:The ownership of the /etc/sysctl.d directory by the root user is important
because this directory hosts kernel configuration. Protection of this
directory is critical for system security. Assigning the ownership to root
ensures exclusive control of the kernel configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
find -P /etc/sysctl.d/ -maxdepth 0 -type d ! -user 0 -exec chown --no-dereference "$newown" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92513-1
- configure_strategy
- directory_owner_etc_sysctld
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the directory_owner_etc_sysctld_newown variable if represented by uid
ansible.builtin.set_fact:
directory_owner_etc_sysctld_newown: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92513-1
- configure_strategy
- directory_owner_etc_sysctld
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on directory /etc/sysctl.d/
ansible.builtin.file:
path: /etc/sysctl.d/
follow: false
state: directory
owner: '{{ directory_owner_etc_sysctld_newown }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92513-1
- configure_strategy
- directory_owner_etc_sysctld
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions On /etc/sysctl.d Directory
[ref]rule To properly set the permissions of /etc/sysctl.d, run the command: $ sudo chmod 0755 /etc/sysctl.d Rationale:Setting correct permissions on the /etc/sysctl.d directory is important
because this directory hosts kernel configuration. Protection of this
directory is critical for system security. Restricting the permissions
ensures exclusive control of the kernel configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
find -H /etc/sysctl.d/ -maxdepth 0 -perm /u+s,g+ws,o+wt -type d -exec chmod u-s,g-ws,o-wt {} \;
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92527-1
- configure_strategy
- directory_permissions_etc_sysctld
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/sysctl.d/ file(s)
ansible.builtin.command: 'find -P /etc/sysctl.d/ -maxdepth 0 -perm /u+s,g+ws,o+wt -type
d '
register: files_found
changed_when: false
failed_when: false
check_mode: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92527-1
- configure_strategy
- directory_permissions_etc_sysctld
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set permissions for /etc/sysctl.d/ file(s)
ansible.builtin.file:
path: '{{ item }}'
mode: u-s,g-ws,o-wt
state: directory
with_items:
- '{{ files_found.stdout_lines }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92527-1
- configure_strategy
- directory_permissions_etc_sysctld
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Ensure All SUID Executables Are Authorized
[ref]ruleThe SUID (set user id) bit should be set only on files that were installed via authorized
means. A straightforward means of identifying unauthorized SUID files is determine if any were
not installed as part of an RPM package, which is cryptographically verified. Investigate the
origin of any unpackaged SUID files. This configuration check considers authorized SUID files
those which were installed via RPM. It is assumed that when an individual has sudo access to
install an RPM and all packages are signed with an organizationally-recognized GPG key, the
software should be considered an approved package on the system. Any SUID file not deployed
through an RPM will be flagged for further review. Warning:
This rule can take a long time to perform the check and might consume a considerable
amount of resources depending on the number of files present on the system. It is not a
problem in most cases, but especially systems with a large number of files can be affected.
See https://access.redhat.com/articles/6999111. Rationale:Executable files with the SUID permission run with the privileges of the owner of the file.
SUID files of uncertain provenance could allow for unprivileged users to elevate privileges.
The presence of these files should be strictly controlled on the system. Identifiers:
CCE-91174-3 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 6.1.11, R56, SLES-15-900150195, 1409 |
Ensure No World-Writable Files Exist
[ref]ruleIt is generally a good idea to remove global (other) write access to a file when it is
discovered. However, check with documentation for specific applications before making changes.
Also, monitor for recurring world-writable files, as these may be symptoms of a misconfigured
application or user account. Finally, this applies to real files and not virtual files that
are a part of pseudo file systems such as sysfs or procfs. Warning:
This rule can take a long time to perform the check and might consume a considerable
amount of resources depending on the number of files present on the system. It is not a
problem in most cases, but especially systems with a large number of files can be affected.
See https://access.redhat.com/articles/6999111. Rationale:Data in world-writable files can be modified by any user on the system. In almost all
circumstances, files can be configured using a combination of user and group permissions to
support whatever legitimate access is needed without the risk caused by world-writable files. Identifiers:
CCE-91233-7 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 6.1.8, R54, SLES-15-900150165, 1409, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
FILTER_NODEV=$(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,)
# Do not consider /sysroot partition because it contains only the physical
# read-only root on bootable containers.
PARTITIONS=$(findmnt -n -l -k -it $FILTER_NODEV | awk '{ print $1 }' | grep -v "/sysroot")
for PARTITION in $PARTITIONS; do
find "${PARTITION}" -xdev -type f -perm -002 -exec chmod o-w {} \; 2>/dev/null
done
# Ensure /tmp is also fixed when tmpfs is used.
if grep "^tmpfs /tmp" /proc/mounts; then
find /tmp -xdev -type f -perm -002 -exec chmod o-w {} \; 2>/dev/null
fi
|
Ensure All Files Are Owned by a User
[ref]ruleIf any files are not owned by a user, then the cause of their lack of ownership should be
investigated. Following this, the files should be deleted or assigned to an appropriate user.
Locate the mount points related to local devices by the following command:
$ findmnt -n -l -k -it $(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,)
For all mount points listed by the previous command, it is necessary to search for files which
do not belong to a valid user using the following command:
$ sudo find MOUNTPOINT -xdev -nouser 2>/dev/null Warning:
For this rule to evaluate centralized user accounts, getent must be working properly
so that running the command getent passwd returns a list of all users in your organization.
If using the System Security Services Daemon (SSSD), enumerate = true must be configured
in your organization's domain to return a complete list of users Warning:
This rule can take a long time to perform the check and might consume a considerable
amount of resources depending on the number of files present on the system. It is not a
problem in most cases, but especially systems with a large number of files can be affected.
See https://access.redhat.com/articles/6999111. Rationale:Unowned files do not directly imply a security problem, but they are generally a sign that
something is amiss. They may be caused by an intruder, by incorrect software installation or
draft software removal, or by failure to remove all files belonging to a deleted account, or
other similar cases. The files should be repaired so they will not cause problems when
accounts are created in the future, and the cause should be discovered and addressed. Identifiers:
CCE-85657-5 References:
11, 12, 13, 14, 15, 16, 18, 3, 5, 9, APO01.06, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.AC-6, PR.DS-5, PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, SLES-15-040400, 6.1.9, R53, SLES-15-900150180, 2.2.6, 2.2, SV-235028r991589_rule |
Enable Kernel Parameter to Enforce DAC on Hardlinks
[ref]ruleTo set the runtime status of the fs.protected_hardlinks kernel parameter, run the following command: $ sudo sysctl -w fs.protected_hardlinks=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: fs.protected_hardlinks = 1 Rationale:By enabling this kernel parameter, users can no longer create soft or hard links to
files which they do not own. Disallowing such hardlinks mitigate vulnerabilities
based on insecure file system accessed by privileged programs, avoiding an
exploitation vector exploiting unsafe use of open() or creat(). Identifiers:
CCE-91252-7 References:
CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000324-GPOS-00125, R14, SLES-15-150750180 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of fs.protected_hardlinks from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*fs.protected_hardlinks.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "fs.protected_hardlinks" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/fs_protected_hardlinks.conf'
#
# Set runtime for fs.protected_hardlinks
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w fs.protected_hardlinks="1"
fi
#
# If fs.protected_hardlinks present in /etc/sysctl.conf, change value to "1"
# else, add "fs.protected_hardlinks = 1" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^fs.protected_hardlinks")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "1"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^fs.protected_hardlinks\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^fs.protected_hardlinks\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-91252-7"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91252-7
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_protected_hardlinks
- name: Enable Kernel Parameter to Enforce DAC on Hardlinks - Set fact for sysctl
paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91252-7
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_protected_hardlinks
- name: Enable Kernel Parameter to Enforce DAC on Hardlinks - Find all files that
contain fs.protected_hardlinks
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*fs.protected_hardlinks\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91252-7
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_protected_hardlinks
- name: Enable Kernel Parameter to Enforce DAC on Hardlinks - Find all files that
set fs.protected_hardlinks to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*fs.protected_hardlinks\s*=\s*1$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91252-7
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_protected_hardlinks
- name: Enable Kernel Parameter to Enforce DAC on Hardlinks - Comment out any occurrences
of fs.protected_hardlinks from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*fs.protected_hardlinks
replace: '#fs.protected_hardlinks'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-91252-7
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_protected_hardlinks
- name: Enable Kernel Parameter to Enforce DAC on Hardlinks - Comment out any occurrences
of fs.protected_hardlinks from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*fs.protected_hardlinks
replace: '#fs.protected_hardlinks'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91252-7
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_protected_hardlinks
- name: Enable Kernel Parameter to Enforce DAC on Hardlinks - Ensure sysctl fs.protected_hardlinks
is set to 1
ansible.posix.sysctl:
name: fs.protected_hardlinks
value: '1'
sysctl_file: /etc/sysctl.d/fs_protected_hardlinks.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91252-7
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_protected_hardlinks
|
Enable Kernel Parameter to Enforce DAC on Symlinks
[ref]ruleTo set the runtime status of the fs.protected_symlinks kernel parameter, run the following command: $ sudo sysctl -w fs.protected_symlinks=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: fs.protected_symlinks = 1 Rationale:By enabling this kernel parameter, symbolic links are permitted to be followed
only when outside a sticky world-writable directory, or when the UID of the
link and follower match, or when the directory owner matches the symlink's owner.
Disallowing such symlinks helps mitigate vulnerabilities based on insecure file system
accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of
open() or creat(). Identifiers:
CCE-91253-5 References:
CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000324-GPOS-00125, R14, SLES-15-150750180 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of fs.protected_symlinks from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*fs.protected_symlinks.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "fs.protected_symlinks" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/fs_protected_symlinks.conf'
#
# Set runtime for fs.protected_symlinks
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w fs.protected_symlinks="1"
fi
#
# If fs.protected_symlinks present in /etc/sysctl.conf, change value to "1"
# else, add "fs.protected_symlinks = 1" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^fs.protected_symlinks")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "1"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^fs.protected_symlinks\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^fs.protected_symlinks\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-91253-5"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91253-5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_protected_symlinks
- name: Enable Kernel Parameter to Enforce DAC on Symlinks - Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91253-5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_protected_symlinks
- name: Enable Kernel Parameter to Enforce DAC on Symlinks - Find all files that contain
fs.protected_symlinks
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*fs.protected_symlinks\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91253-5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_protected_symlinks
- name: Enable Kernel Parameter to Enforce DAC on Symlinks - Find all files that set
fs.protected_symlinks to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*fs.protected_symlinks\s*=\s*1$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91253-5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_protected_symlinks
- name: Enable Kernel Parameter to Enforce DAC on Symlinks - Comment out any occurrences
of fs.protected_symlinks from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*fs.protected_symlinks
replace: '#fs.protected_symlinks'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-91253-5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_protected_symlinks
- name: Enable Kernel Parameter to Enforce DAC on Symlinks - Comment out any occurrences
of fs.protected_symlinks from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*fs.protected_symlinks
replace: '#fs.protected_symlinks'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91253-5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_protected_symlinks
- name: Enable Kernel Parameter to Enforce DAC on Symlinks - Ensure sysctl fs.protected_symlinks
is set to 1
ansible.posix.sysctl:
name: fs.protected_symlinks
value: '1'
sysctl_file: /etc/sysctl.d/fs_protected_symlinks.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91253-5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_protected_symlinks
|
Restrict Dynamic Mounting and Unmounting of
Filesystems
[ref]groupLinux includes a number of facilities for the automated addition
and removal of filesystems on a running system. These facilities may be
necessary in many environments, but this capability also carries some risk -- whether direct
risk from allowing users to introduce arbitrary filesystems,
or risk that software flaws in the automated mount facility itself could
allow an attacker to compromise the system.
This command can be used to list the types of filesystems that are
available to the currently executing kernel:
$ find /lib/modules/`uname -r`/kernel/fs -type f -name '*.ko'
If these filesystems are not required then they can be explicitly disabled
in a configuratio file in /etc/modprobe.d. |
| contains 11 rules |
Disable the Automounter
[ref]ruleThe autofs daemon mounts and unmounts filesystems, such as user
home directories shared via NFS, on demand. In addition, autofs can be used to handle
removable media, and the default configuration provides the cdrom device as /misc/cd.
However, this method of providing access to removable media is not common, so autofs
can almost always be disabled if NFS is not in use. Even if NFS is required, it may be
possible to configure filesystem mounts statically by editing /etc/fstab
rather than relying on the automounter.
The autofs service can be disabled with the following command:
$ sudo systemctl mask --now autofs.service Rationale:Disabling the automounter permits the administrator to
statically control filesystem mounting through /etc/fstab.
Additionally, automatically mounting filesystems permits easy introduction of
unknown devices, thereby facilitating malicious activity. Identifiers:
CCE-83278-2 References:
1, 12, 15, 16, 5, APO13.01, DSS01.04, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.4.6, 164.308(a)(3)(i), 164.308(a)(3)(ii)(A), 164.310(d)(1), 164.310(d)(2), 164.312(a)(1), 164.312(a)(2)(iv), 164.312(b), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.6, A.11.2.6, A.13.1.1, A.13.2.1, A.18.1.4, A.6.2.1, A.6.2.2, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CM-7(a), CM-7(b), CM-6(a), MP-7, PR.AC-1, PR.AC-3, PR.AC-6, PR.AC-7, SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227, SLES-15-010240, 1.1.23, SLES-15-300150015, SV-234823r958498_rule Remediation script: (show)
[customizations.services]
masked = ["autofs"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_autofs
class disable_autofs {
service {'autofs':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if ( rpm --quiet -q autofs && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base ); then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'autofs.service'
fi
"$SYSTEMCTL_EXEC" disable 'autofs.service'
"$SYSTEMCTL_EXEC" mask 'autofs.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files autofs.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'autofs.socket'
fi
"$SYSTEMCTL_EXEC" mask 'autofs.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'autofs.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83278-2
- DISA-STIG-SLES-15-010240
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_autofs_disabled
- name: Disable the Automounter - Disable service autofs
block:
- name: Disable the Automounter - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable the Automounter - Ensure autofs.service is Masked
ansible.builtin.systemd:
name: autofs.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("autofs.service", multiline=True)
- name: Unit Socket Exists - autofs.socket
ansible.builtin.command: systemctl -q list-unit-files autofs.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable the Automounter - Disable Socket autofs
ansible.builtin.systemd:
name: autofs.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("autofs.socket", multiline=True)
tags:
- CCE-83278-2
- DISA-STIG-SLES-15-010240
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_autofs_disabled
- special_service_block
when: ( "autofs" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
|
Disable Mounting of cramfs
[ref]rule
To configure the system to prevent the cramfs
kernel module from being loaded, add the following line to the file /etc/modprobe.d/cramfs.conf:
install cramfs /bin/false
This entry will cause a non-zero return value during a cramfs module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install cramfs /bin/true
This effectively prevents usage of this uncommon filesystem.
The cramfs filesystem type is a compressed read-only
Linux filesystem embedded in small footprint systems. A
cramfs image can be used without having to first
decompress the image.Rationale:Removing support for unneeded filesystem types reduces the local attack surface
of the server. Identifiers:
CCE-92451-4 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000095-GPOS-00049, 1.1.1.1, SLES-15-150150015 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -q -m 1 "^install cramfs" /etc/modprobe.d/cramfs.conf ; then
sed -i 's#^install cramfs.*#install cramfs /bin/false#g' /etc/modprobe.d/cramfs.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/cramfs.conf
echo "install cramfs /bin/false" >> /etc/modprobe.d/cramfs.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist cramfs$" /etc/modprobe.d/cramfs.conf ; then
echo "blacklist cramfs" >> /etc/modprobe.d/cramfs.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92451-4
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_cramfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'cramfs' is disabled
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/cramfs.conf
regexp: install\s+cramfs
line: install cramfs /bin/false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92451-4
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_cramfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'cramfs' is blacklisted
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/cramfs.conf
regexp: ^blacklist cramfs$
line: blacklist cramfs
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92451-4
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_cramfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
|
Disable Mounting of freevxfs
[ref]rule
To configure the system to prevent the freevxfs
kernel module from being loaded, add the following line to the file /etc/modprobe.d/freevxfs.conf:
install freevxfs /bin/false
This entry will cause a non-zero return value during a freevxfs module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install freevxfs /bin/true
This effectively prevents usage of this uncommon filesystem.Rationale:Linux kernel modules which implement filesystems that are not needed by the
local system should be disabled. Identifiers:
CCE-92573-5 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SLES-15-150150030 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -q -m 1 "^install freevxfs" /etc/modprobe.d/freevxfs.conf ; then
sed -i 's#^install freevxfs.*#install freevxfs /bin/false#g' /etc/modprobe.d/freevxfs.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/freevxfs.conf
echo "install freevxfs /bin/false" >> /etc/modprobe.d/freevxfs.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist freevxfs$" /etc/modprobe.d/freevxfs.conf ; then
echo "blacklist freevxfs" >> /etc/modprobe.d/freevxfs.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92573-5
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_freevxfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'freevxfs' is disabled
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/freevxfs.conf
regexp: install\s+freevxfs
line: install freevxfs /bin/false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92573-5
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_freevxfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'freevxfs' is blacklisted
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/freevxfs.conf
regexp: ^blacklist freevxfs$
line: blacklist freevxfs
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92573-5
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_freevxfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
|
Disable Mounting of hfs
[ref]rule
To configure the system to prevent the hfs
kernel module from being loaded, add the following line to the file /etc/modprobe.d/hfs.conf:
install hfs /bin/false
This entry will cause a non-zero return value during a hfs module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install hfs /bin/true
This effectively prevents usage of this uncommon filesystem.Rationale:Linux kernel modules which implement filesystems that are not needed by the
local system should be disabled. Identifiers:
CCE-92574-3 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SLES-15-150150045 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -q -m 1 "^install hfs" /etc/modprobe.d/hfs.conf ; then
sed -i 's#^install hfs.*#install hfs /bin/false#g' /etc/modprobe.d/hfs.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/hfs.conf
echo "install hfs /bin/false" >> /etc/modprobe.d/hfs.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist hfs$" /etc/modprobe.d/hfs.conf ; then
echo "blacklist hfs" >> /etc/modprobe.d/hfs.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92574-3
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_hfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'hfs' is disabled
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/hfs.conf
regexp: install\s+hfs
line: install hfs /bin/false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92574-3
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_hfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'hfs' is blacklisted
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/hfs.conf
regexp: ^blacklist hfs$
line: blacklist hfs
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92574-3
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_hfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
|
Disable Mounting of hfsplus
[ref]rule
To configure the system to prevent the hfsplus
kernel module from being loaded, add the following line to the file /etc/modprobe.d/hfsplus.conf:
install hfsplus /bin/false
This entry will cause a non-zero return value during a hfsplus module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install hfsplus /bin/true
This effectively prevents usage of this uncommon filesystem.Rationale:Linux kernel modules which implement filesystems that are not needed by the
local system should be disabled. Identifiers:
CCE-92575-0 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SLES-15-150150060 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -q -m 1 "^install hfsplus" /etc/modprobe.d/hfsplus.conf ; then
sed -i 's#^install hfsplus.*#install hfsplus /bin/false#g' /etc/modprobe.d/hfsplus.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/hfsplus.conf
echo "install hfsplus /bin/false" >> /etc/modprobe.d/hfsplus.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist hfsplus$" /etc/modprobe.d/hfsplus.conf ; then
echo "blacklist hfsplus" >> /etc/modprobe.d/hfsplus.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92575-0
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_hfsplus_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'hfsplus' is disabled
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/hfsplus.conf
regexp: install\s+hfsplus
line: install hfsplus /bin/false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92575-0
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_hfsplus_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'hfsplus' is blacklisted
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/hfsplus.conf
regexp: ^blacklist hfsplus$
line: blacklist hfsplus
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92575-0
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_hfsplus_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
|
Disable Mounting of jffs2
[ref]rule
To configure the system to prevent the jffs2
kernel module from being loaded, add the following line to the file /etc/modprobe.d/jffs2.conf:
install jffs2 /bin/false
This entry will cause a non-zero return value during a jffs2 module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install jffs2 /bin/true
This effectively prevents usage of this uncommon filesystem.Rationale:Linux kernel modules which implement filesystems that are not needed by the
local system should be disabled. Identifiers:
CCE-92577-6 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SLES-15-150150075 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -q -m 1 "^install jffs2" /etc/modprobe.d/jffs2.conf ; then
sed -i 's#^install jffs2.*#install jffs2 /bin/false#g' /etc/modprobe.d/jffs2.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/jffs2.conf
echo "install jffs2 /bin/false" >> /etc/modprobe.d/jffs2.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist jffs2$" /etc/modprobe.d/jffs2.conf ; then
echo "blacklist jffs2" >> /etc/modprobe.d/jffs2.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92577-6
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_jffs2_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'jffs2' is disabled
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/jffs2.conf
regexp: install\s+jffs2
line: install jffs2 /bin/false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92577-6
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_jffs2_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'jffs2' is blacklisted
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/jffs2.conf
regexp: ^blacklist jffs2$
line: blacklist jffs2
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92577-6
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_jffs2_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
|
Ensure overlayfs kernel module is not available
[ref]rule
To configure the system to prevent the overlayfs
kernel module from being loaded, add the following line to the file /etc/modprobe.d/overlayfs.conf:
install overlayfs /bin/false
This entry will cause a non-zero return value during a overlayfs module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install overlayfs /bin/true
overlayfs is a Linux filesystem that layers multiple filesystems to create a single
unified view which allows a user to "merge" several mount points into a unified
filesystem.Rationale:The overlayfs has known CVE's. Disabling the overlayfs reduces the local attack
surface by removing support for unnecessary filesystem types and mitigates potential
risks associated with unauthorized execution of setuid files, enhancing the overall
system security. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -q -m 1 "^install overlayfs" /etc/modprobe.d/overlayfs.conf ; then
sed -i 's#^install overlayfs.*#install overlayfs /bin/false#g' /etc/modprobe.d/overlayfs.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/overlayfs.conf
echo "install overlayfs /bin/false" >> /etc/modprobe.d/overlayfs.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist overlayfs$" /etc/modprobe.d/overlayfs.conf ; then
echo "blacklist overlayfs" >> /etc/modprobe.d/overlayfs.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92579-2
- disable_strategy
- kernel_module_overlayfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'overlayfs' is disabled
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/overlayfs.conf
regexp: install\s+overlayfs
line: install overlayfs /bin/false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92579-2
- disable_strategy
- kernel_module_overlayfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'overlayfs' is blacklisted
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/overlayfs.conf
regexp: ^blacklist overlayfs$
line: blacklist overlayfs
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92579-2
- disable_strategy
- kernel_module_overlayfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
|
Disable Mounting of squashfs
[ref]rule
To configure the system to prevent the squashfs
kernel module from being loaded, add the following line to the file /etc/modprobe.d/squashfs.conf:
install squashfs /bin/false
This entry will cause a non-zero return value during a squashfs module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install squashfs /bin/true
This effectively prevents usage of this uncommon filesystem.
The squashfs filesystem type is a compressed read-only Linux
filesystem embedded in small footprint systems (similar to
cramfs). A squashfs image can be used without having
to first decompress the image.Rationale:Removing support for unneeded filesystem types reduces the local attack
surface of the system. Identifiers:
CCE-92452-2 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 1.1.1.1, SLES-15-150150105 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -q -m 1 "^install squashfs" /etc/modprobe.d/squashfs.conf ; then
sed -i 's#^install squashfs.*#install squashfs /bin/false#g' /etc/modprobe.d/squashfs.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/squashfs.conf
echo "install squashfs /bin/false" >> /etc/modprobe.d/squashfs.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist squashfs$" /etc/modprobe.d/squashfs.conf ; then
echo "blacklist squashfs" >> /etc/modprobe.d/squashfs.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92452-2
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_squashfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'squashfs' is disabled
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/squashfs.conf
regexp: install\s+squashfs
line: install squashfs /bin/false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92452-2
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_squashfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'squashfs' is blacklisted
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/squashfs.conf
regexp: ^blacklist squashfs$
line: blacklist squashfs
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92452-2
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_squashfs_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
|
Disable Mounting of udf
[ref]rule
To configure the system to prevent the udf
kernel module from being loaded, add the following line to the file /etc/modprobe.d/udf.conf:
install udf /bin/false
This entry will cause a non-zero return value during a udf module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install udf /bin/true
This effectively prevents usage of this uncommon filesystem.
The udf filesystem type is the universal disk format
used to implement the ISO/IEC 13346 and ECMA-167 specifications.
This is an open vendor filesystem type for data storage on a broad
range of media. This filesystem type is necessary to support
writing DVDs and newer optical disc formats.Rationale:Removing support for unneeded filesystem types reduces the local
attack surface of the system. Identifiers:
CCE-92453-0 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 1.1.1.2, SLES-15-150150120 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -q -m 1 "^install udf" /etc/modprobe.d/udf.conf ; then
sed -i 's#^install udf.*#install udf /bin/false#g' /etc/modprobe.d/udf.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/udf.conf
echo "install udf /bin/false" >> /etc/modprobe.d/udf.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist udf$" /etc/modprobe.d/udf.conf ; then
echo "blacklist udf" >> /etc/modprobe.d/udf.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92453-0
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_udf_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'udf' is disabled
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/udf.conf
regexp: install\s+udf
line: install udf /bin/false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92453-0
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_udf_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'udf' is blacklisted
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/udf.conf
regexp: ^blacklist udf$
line: blacklist udf
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92453-0
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_udf_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
|
Disable Modprobe Loading of USB Storage Driver
[ref]ruleTo prevent USB storage devices from being used, configure the kernel module loading system
to prevent automatic loading of the USB storage driver.
To configure the system to prevent the usb-storage
kernel module from being loaded, add the following line to the file /etc/modprobe.d/usb-storage.conf:
install usb-storage /bin/false
This entry will cause a non-zero return value during a usb-storage module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install usb-storage /bin/true
This will prevent the modprobe program from loading the usb-storage
module, but will not prevent an administrator (or another program) from using the
insmod program to load the module manually.Rationale:USB storage devices such as thumb drives can be used to introduce
malicious software. Identifiers:
CCE-83294-9 References:
1, 12, 15, 16, 5, APO13.01, DSS01.04, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.21, 164.308(a)(3)(i), 164.308(a)(3)(ii)(A), 164.310(d)(1), 164.310(d)(2), 164.312(a)(1), 164.312(a)(2)(iv), 164.312(b), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.6, A.11.2.6, A.13.1.1, A.13.2.1, A.18.1.4, A.6.2.1, A.6.2.2, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CM-7(a), CM-7(b), CM-6(a), MP-7, PR.AC-1, PR.AC-3, PR.AC-6, PR.AC-7, SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227, SRG-APP-000141-CTR-000315, SLES-15-010480, 1.1.23, SLES-15-300150015, 3.4.2, 3.4, SV-234856r958820_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -q -m 1 "^install usb-storage" /etc/modprobe.d/usb-storage.conf ; then
sed -i 's#^install usb-storage.*#install usb-storage /bin/false#g' /etc/modprobe.d/usb-storage.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/usb-storage.conf
echo "install usb-storage /bin/false" >> /etc/modprobe.d/usb-storage.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist usb-storage$" /etc/modprobe.d/usb-storage.conf ; then
echo "blacklist usb-storage" >> /etc/modprobe.d/usb-storage.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83294-9
- DISA-STIG-SLES-15-010480
- NIST-800-171-3.1.21
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- PCI-DSSv4-3.4
- PCI-DSSv4-3.4.2
- disable_strategy
- kernel_module_usb-storage_disabled
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- name: Ensure kernel module 'usb-storage' is disabled
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/usb-storage.conf
regexp: install\s+usb-storage
line: install usb-storage /bin/false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83294-9
- DISA-STIG-SLES-15-010480
- NIST-800-171-3.1.21
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- PCI-DSSv4-3.4
- PCI-DSSv4-3.4.2
- disable_strategy
- kernel_module_usb-storage_disabled
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- name: Ensure kernel module 'usb-storage' is blacklisted
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/usb-storage.conf
regexp: ^blacklist usb-storage$
line: blacklist usb-storage
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83294-9
- DISA-STIG-SLES-15-010480
- NIST-800-171-3.1.21
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- PCI-DSSv4-3.4
- PCI-DSSv4-3.4.2
- disable_strategy
- kernel_module_usb-storage_disabled
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
|
Disable Mounting of vFAT filesystems
[ref]rule
To configure the system to prevent the vfat
kernel module from being loaded, add the following line to the file /etc/modprobe.d/vfat.conf:
install vfat /bin/false
This entry will cause a non-zero return value during a vfat module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install vfat /bin/true
This effectively prevents usage of this uncommon filesystem.
The vFAT filesystem format is primarily used on older
windows systems and portable USB drives or flash modules. It comes
in three types FAT12, FAT16, and FAT32
all of which are supported by the vfat kernel module.Rationale:Removing support for unneeded filesystems reduces the local attack
surface of the system. Identifiers:
CCE-92454-8 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 1.1.1.3, SLES-15-150150135 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if ( [ ! -d /sys/firmware/efi ] && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base ); then
if LC_ALL=C grep -q -m 1 "^install vfat" /etc/modprobe.d/vfat.conf ; then
sed -i 's#^install vfat.*#install vfat /bin/false#g' /etc/modprobe.d/vfat.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/vfat.conf
echo "install vfat /bin/false" >> /etc/modprobe.d/vfat.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist vfat$" /etc/modprobe.d/vfat.conf ; then
echo "blacklist vfat" >> /etc/modprobe.d/vfat.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92454-8
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_vfat_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'vfat' is disabled
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/vfat.conf
regexp: install\s+vfat
line: install vfat /bin/false
when: ( "/boot/efi" not in ansible_mounts | map(attribute="mount") | list and ("kernel-default"
in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
)
tags:
- CCE-92454-8
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_vfat_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'vfat' is blacklisted
ansible.builtin.lineinfile:
create: true
dest: /etc/modprobe.d/vfat.conf
regexp: ^blacklist vfat$
line: blacklist vfat
when: ( "/boot/efi" not in ansible_mounts | map(attribute="mount") | list and ("kernel-default"
in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
)
tags:
- CCE-92454-8
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_vfat_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
|
Restrict Partition Mount Options
[ref]groupSystem partitions can be mounted with certain options
that limit what files on those partitions can do. These options
are set in the /etc/fstab configuration file, and can be
used to make certain types of malicious behavior more difficult. |
| contains 19 rules |
Add nodev Option to /dev/shm
[ref]ruleThe nodev mount option can be used to prevent creation of device
files in /dev/shm. Legitimate character and block devices should
not exist within temporary directories like /dev/shm.
Add the nodev option to the fourth column of
/etc/fstab for the line which controls mounting of
/dev/shm. Rationale:The only legitimate location for device files is the /dev directory
located on the root partition. The only exception to this is chroot jails. Identifiers:
CCE-92457-1 References:
11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.8, SLES-15-150150225, 1409 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ); then
function perform_remediation {
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /dev/shm)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type="tmpfs"
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo "tmpfs /dev/shm tmpfs defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nodev"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
fi
if mkdir -p "/dev/shm"; then
if mountpoint -q "/dev/shm"; then
mount -o remount --target "/dev/shm"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92457-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_nodev
- no_reboot_needed
- name: 'Add nodev Option to /dev/shm: Check information associated to mountpoint'
command: findmnt '/dev/shm'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when: ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
tags:
- CCE-92457-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_nodev
- no_reboot_needed
- name: 'Add nodev Option to /dev/shm: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-92457-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_nodev
- no_reboot_needed
- name: 'Add nodev Option to /dev/shm: If /dev/shm not mounted, craft mount_info manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /dev/shm
- tmpfs
- tmpfs
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- ("" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-92457-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_nodev
- no_reboot_needed
- name: 'Add nodev Option to /dev/shm: Make sure nodev option is part of the to /dev/shm
options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- mount_info is defined and "nodev" not in mount_info.options
tags:
- CCE-92457-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_nodev
- no_reboot_needed
- name: 'Add nodev Option to /dev/shm: Ensure /dev/shm is mounted with nodev option'
mount:
path: /dev/shm
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("" |
length == 0)
tags:
- CCE-92457-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_nodev
- no_reboot_needed
|
Add noexec Option to /dev/shm
[ref]ruleThe noexec mount option can be used to prevent binaries
from being executed out of /dev/shm.
It can be dangerous to allow the execution of binaries
from world-writable temporary storage directories such as /dev/shm.
Add the noexec option to the fourth column of
/etc/fstab for the line which controls mounting of
/dev/shm. Rationale:Allowing users to execute binaries from world-writable directories
such as /dev/shm can expose the system to potential compromise. Identifiers:
CCE-92456-3 References:
11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.7, SLES-15-150150255, 1409 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ); then
function perform_remediation {
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /dev/shm)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type="tmpfs"
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo "tmpfs /dev/shm tmpfs defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "noexec"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
fi
if mkdir -p "/dev/shm"; then
if mountpoint -q "/dev/shm"; then
mount -o remount --target "/dev/shm"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92456-3
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_noexec
- no_reboot_needed
- name: 'Add noexec Option to /dev/shm: Check information associated to mountpoint'
command: findmnt '/dev/shm'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when: ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
tags:
- CCE-92456-3
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_noexec
- no_reboot_needed
- name: 'Add noexec Option to /dev/shm: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-92456-3
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_noexec
- no_reboot_needed
- name: 'Add noexec Option to /dev/shm: If /dev/shm not mounted, craft mount_info
manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /dev/shm
- tmpfs
- tmpfs
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- ("" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-92456-3
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_noexec
- no_reboot_needed
- name: 'Add noexec Option to /dev/shm: Make sure noexec option is part of the to
/dev/shm options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- mount_info is defined and "noexec" not in mount_info.options
tags:
- CCE-92456-3
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_noexec
- no_reboot_needed
- name: 'Add noexec Option to /dev/shm: Ensure /dev/shm is mounted with noexec option'
mount:
path: /dev/shm
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("" |
length == 0)
tags:
- CCE-92456-3
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_noexec
- no_reboot_needed
|
Add nosuid Option to /dev/shm
[ref]ruleThe nosuid mount option can be used to prevent execution
of setuid programs in /dev/shm. The SUID and SGID permissions should not
be required in these world-writable directories.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/dev/shm. Rationale:The presence of SUID and SGID executables should be tightly controlled. Users
should not be able to execute SUID or SGID binaries from temporary storage partitions. Identifiers:
CCE-92458-9 References:
11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.9, SLES-15-150150240, 1409 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ); then
function perform_remediation {
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /dev/shm)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type="tmpfs"
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo "tmpfs /dev/shm tmpfs defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nosuid"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
fi
if mkdir -p "/dev/shm"; then
if mountpoint -q "/dev/shm"; then
mount -o remount --target "/dev/shm"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92458-9
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /dev/shm: Check information associated to mountpoint'
command: findmnt '/dev/shm'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when: ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
tags:
- CCE-92458-9
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /dev/shm: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-92458-9
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /dev/shm: If /dev/shm not mounted, craft mount_info
manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /dev/shm
- tmpfs
- tmpfs
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- ("" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-92458-9
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /dev/shm: Make sure nosuid option is part of the to
/dev/shm options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- mount_info is defined and "nosuid" not in mount_info.options
tags:
- CCE-92458-9
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /dev/shm: Ensure /dev/shm is mounted with nosuid option'
mount:
path: /dev/shm
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("" |
length == 0)
tags:
- CCE-92458-9
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_dev_shm_nosuid
- no_reboot_needed
|
Add nodev Option to /home
[ref]ruleThe nodev mount option can be used to prevent device files from
being created in /home.
Legitimate character and block devices should exist only in
the /dev directory on the root partition or within chroot
jails built for system services.
Add the nodev option to the fourth column of
/etc/fstab for the line which controls mounting of
/home. Rationale:The only legitimate location for device files is the /dev directory
located on the root partition. The only exception to this is chroot jails. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/home" > /dev/null || findmnt --fstab "/home" > /dev/null; }; then
function perform_remediation {
# the mount point /home has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/home")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/home' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /home in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /home)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /home defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nodev"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
fi
if mkdir -p "/home"; then
if mountpoint -q "/home"; then
mount -o remount --target "/home"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92460-5
- configure_strategy
- high_disruption
- low_complexity
- mount_option_home_nodev
- no_reboot_needed
- unknown_severity
- name: 'Add nodev Option to /home: Check information associated to mountpoint'
command: findmnt --fstab '/home'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/home" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-92460-5
- configure_strategy
- high_disruption
- low_complexity
- mount_option_home_nodev
- no_reboot_needed
- unknown_severity
- name: 'Add nodev Option to /home: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/home" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-92460-5
- configure_strategy
- high_disruption
- low_complexity
- mount_option_home_nodev
- no_reboot_needed
- unknown_severity
- name: 'Add nodev Option to /home: If /home not mounted, craft mount_info manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /home
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/home" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-92460-5
- configure_strategy
- high_disruption
- low_complexity
- mount_option_home_nodev
- no_reboot_needed
- unknown_severity
- name: 'Add nodev Option to /home: Make sure nodev option is part of the to /home
options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/home" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "nodev" not in mount_info.options
tags:
- CCE-92460-5
- configure_strategy
- high_disruption
- low_complexity
- mount_option_home_nodev
- no_reboot_needed
- unknown_severity
- name: 'Add nodev Option to /home: Ensure /home is mounted with nodev option'
mount:
path: /home
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/home" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-92460-5
- configure_strategy
- high_disruption
- low_complexity
- mount_option_home_nodev
- no_reboot_needed
- unknown_severity
|
Add nosuid Option to /home
[ref]ruleThe nosuid mount option can be used to prevent
execution of setuid programs in /home. The SUID and SGID permissions
should not be required in these user data directories.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/home. Rationale:The presence of SUID and SGID executables should be tightly controlled. Users
should not be able to execute SUID or SGID binaries from user home directory partitions. Identifiers:
CCE-85633-6 References:
11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, SRG-OS-000480-GPOS-00227, SLES-15-040140, R28, SLES-15-150150300, SV-234998r991589_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/home" > /dev/null || findmnt --fstab "/home" > /dev/null; }; then
function perform_remediation {
# the mount point /home has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/home")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/home' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /home in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /home)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /home defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nosuid"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
fi
if mkdir -p "/home"; then
if mountpoint -q "/home"; then
mount -o remount --target "/home"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85633-6
- DISA-STIG-SLES-15-040140
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_home_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /home: Check information associated to mountpoint'
command: findmnt --fstab '/home'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/home" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-85633-6
- DISA-STIG-SLES-15-040140
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_home_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /home: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/home" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-85633-6
- DISA-STIG-SLES-15-040140
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_home_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /home: If /home not mounted, craft mount_info manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /home
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/home" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-85633-6
- DISA-STIG-SLES-15-040140
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_home_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /home: Make sure nosuid option is part of the to /home
options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/home" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "nosuid" not in mount_info.options
tags:
- CCE-85633-6
- DISA-STIG-SLES-15-040140
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_home_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /home: Ensure /home is mounted with nosuid option'
mount:
path: /home
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/home" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-85633-6
- DISA-STIG-SLES-15-040140
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_home_nosuid
- no_reboot_needed
|
Add nodev Option to /tmp
[ref]ruleThe nodev mount option can be used to prevent device files from
being created in /tmp. Legitimate character and block devices
should not exist within temporary directories like /tmp.
Add the nodev option to the fourth column of
/etc/fstab for the line which controls mounting of
/tmp. Rationale:The only legitimate location for device files is the /dev directory
located on the root partition. The only exception to this is chroot jails. Identifiers:
CCE-92455-5 References:
11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.4, SLES-15-150150165 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/tmp" > /dev/null || findmnt --fstab "/tmp" > /dev/null; }; then
function perform_remediation {
# the mount point /tmp has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/tmp")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /tmp in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /tmp)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /tmp defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nodev"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
fi
if mkdir -p "/tmp"; then
if mountpoint -q "/tmp"; then
mount -o remount --target "/tmp"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92455-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_nodev
- no_reboot_needed
- name: 'Add nodev Option to /tmp: Check information associated to mountpoint'
command: findmnt --fstab '/tmp'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-92455-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_nodev
- no_reboot_needed
- name: 'Add nodev Option to /tmp: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-92455-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_nodev
- no_reboot_needed
- name: 'Add nodev Option to /tmp: If /tmp not mounted, craft mount_info manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /tmp
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-92455-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_nodev
- no_reboot_needed
- name: 'Add nodev Option to /tmp: Make sure nodev option is part of the to /tmp options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "nodev" not in mount_info.options
tags:
- CCE-92455-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_nodev
- no_reboot_needed
- name: 'Add nodev Option to /tmp: Ensure /tmp is mounted with nodev option'
mount:
path: /tmp
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-92455-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_nodev
- no_reboot_needed
|
Add noexec Option to /tmp
[ref]ruleThe noexec mount option can be used to prevent binaries
from being executed out of /tmp.
Add the noexec option to the fourth column of
/etc/fstab for the line which controls mounting of
/tmp. Rationale:Allowing users to execute binaries from world-writable directories
such as /tmp should never be necessary in normal operation and
can expose the system to potential compromise. Identifiers:
CCE-91272-5 References:
11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.3, R28, SLES-15-150150195 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/tmp" > /dev/null || findmnt --fstab "/tmp" > /dev/null; }; then
function perform_remediation {
# the mount point /tmp has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/tmp")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /tmp in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /tmp)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /tmp defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "noexec"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
fi
if mkdir -p "/tmp"; then
if mountpoint -q "/tmp"; then
mount -o remount --target "/tmp"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91272-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_noexec
- no_reboot_needed
- name: 'Add noexec Option to /tmp: Check information associated to mountpoint'
command: findmnt --fstab '/tmp'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-91272-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_noexec
- no_reboot_needed
- name: 'Add noexec Option to /tmp: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-91272-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_noexec
- no_reboot_needed
- name: 'Add noexec Option to /tmp: If /tmp not mounted, craft mount_info manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /tmp
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-91272-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_noexec
- no_reboot_needed
- name: 'Add noexec Option to /tmp: Make sure noexec option is part of the to /tmp
options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "noexec" not in mount_info.options
tags:
- CCE-91272-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_noexec
- no_reboot_needed
- name: 'Add noexec Option to /tmp: Ensure /tmp is mounted with noexec option'
mount:
path: /tmp
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-91272-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_noexec
- no_reboot_needed
|
Add nosuid Option to /tmp
[ref]ruleThe nosuid mount option can be used to prevent
execution of setuid programs in /tmp. The SUID and SGID permissions
should not be required in these world-writable directories.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/tmp. Rationale:The presence of SUID and SGID executables should be tightly controlled. Users
should not be able to execute SUID or SGID binaries from temporary storage partitions. Identifiers:
CCE-91273-3 References:
11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.5, R28, SLES-15-150150180 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/tmp" > /dev/null || findmnt --fstab "/tmp" > /dev/null; }; then
function perform_remediation {
# the mount point /tmp has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/tmp")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /tmp in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /tmp)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /tmp defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nosuid"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
fi
if mkdir -p "/tmp"; then
if mountpoint -q "/tmp"; then
mount -o remount --target "/tmp"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91273-3
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /tmp: Check information associated to mountpoint'
command: findmnt --fstab '/tmp'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-91273-3
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /tmp: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-91273-3
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /tmp: If /tmp not mounted, craft mount_info manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /tmp
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-91273-3
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /tmp: Make sure nosuid option is part of the to /tmp
options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "nosuid" not in mount_info.options
tags:
- CCE-91273-3
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /tmp: Ensure /tmp is mounted with nosuid option'
mount:
path: /tmp
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/tmp" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-91273-3
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_tmp_nosuid
- no_reboot_needed
|
Add nodev Option to /var/log/audit
[ref]ruleThe nodev mount option can be used to prevent device files from
being created in /var/log/audit.
Legitimate character and block devices should exist only in
the /dev directory on the root partition or within chroot
jails built for system services.
Add the nodev option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/log/audit. Rationale:The only legitimate location for device files is the /dev directory
located on the root partition. The only exception to this is chroot jails. Identifiers:
CCE-92583-4 References:
CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, FMT_SMF_EXT.1, SRG-OS-000368-GPOS-00154, SLES-15-150150495 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/var/log/audit" > /dev/null || findmnt --fstab "/var/log/audit" > /dev/null; }; then
function perform_remediation {
# the mount point /var/log/audit has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/log/audit")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/var/log/audit' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /var/log/audit in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/log/audit)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /var/log/audit defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nodev"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
fi
if mkdir -p "/var/log/audit"; then
if mountpoint -q "/var/log/audit"; then
mount -o remount --target "/var/log/audit"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92583-4
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/log/audit: Check information associated to mountpoint'
command: findmnt --fstab '/var/log/audit'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-92583-4
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/log/audit: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-92583-4
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/log/audit: If /var/log/audit not mounted, craft
mount_info manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /var/log/audit
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-92583-4
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/log/audit: Make sure nodev option is part of the
to /var/log/audit options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "nodev" not in mount_info.options
tags:
- CCE-92583-4
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/log/audit: Ensure /var/log/audit is mounted with
nodev option'
mount:
path: /var/log/audit
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-92583-4
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_nodev
- no_reboot_needed
|
Add noexec Option to /var/log/audit
[ref]ruleThe noexec mount option can be used to prevent binaries
from being executed out of /var/log/audit.
Add the noexec option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/log/audit. Rationale:Allowing users to execute binaries from directories containing audit log files
such as /var/log/audit should never be necessary in normal operation and
can expose the system to potential compromise. Identifiers:
CCE-92584-2 References:
CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, FMT_SMF_EXT.1, SRG-OS-000368-GPOS-00154, SLES-15-150150525 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/var/log/audit" > /dev/null || findmnt --fstab "/var/log/audit" > /dev/null; }; then
function perform_remediation {
# the mount point /var/log/audit has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/log/audit")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/var/log/audit' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /var/log/audit in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/log/audit)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /var/log/audit defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "noexec"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
fi
if mkdir -p "/var/log/audit"; then
if mountpoint -q "/var/log/audit"; then
mount -o remount --target "/var/log/audit"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92584-2
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/log/audit: Check information associated to mountpoint'
command: findmnt --fstab '/var/log/audit'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-92584-2
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/log/audit: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-92584-2
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/log/audit: If /var/log/audit not mounted, craft
mount_info manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /var/log/audit
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-92584-2
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/log/audit: Make sure noexec option is part of the
to /var/log/audit options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "noexec" not in mount_info.options
tags:
- CCE-92584-2
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/log/audit: Ensure /var/log/audit is mounted with
noexec option'
mount:
path: /var/log/audit
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-92584-2
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_noexec
- no_reboot_needed
|
Add nosuid Option to /var/log/audit
[ref]ruleThe nosuid mount option can be used to prevent
execution of setuid programs in /var/log/audit. The SUID and SGID permissions
should not be required in directories containing audit log files.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/log/audit. Rationale:The presence of SUID and SGID executables should be tightly controlled. Users
should not be able to execute SUID or SGID binaries from partitions
designated for audit log files. Identifiers:
CCE-92587-5 References:
CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, FMT_SMF_EXT.1, SRG-OS-000368-GPOS-00154, SLES-15-150150510 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/var/log/audit" > /dev/null || findmnt --fstab "/var/log/audit" > /dev/null; }; then
function perform_remediation {
# the mount point /var/log/audit has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/log/audit")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/var/log/audit' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /var/log/audit in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/log/audit)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /var/log/audit defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nosuid"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
fi
if mkdir -p "/var/log/audit"; then
if mountpoint -q "/var/log/audit"; then
mount -o remount --target "/var/log/audit"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92587-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/log/audit: Check information associated to mountpoint'
command: findmnt --fstab '/var/log/audit'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-92587-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/log/audit: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-92587-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/log/audit: If /var/log/audit not mounted, craft
mount_info manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /var/log/audit
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-92587-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/log/audit: Make sure nosuid option is part of the
to /var/log/audit options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "nosuid" not in mount_info.options
tags:
- CCE-92587-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/log/audit: Ensure /var/log/audit is mounted with
nosuid option'
mount:
path: /var/log/audit
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-92587-5
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_audit_nosuid
- no_reboot_needed
|
Add nodev Option to /var/log
[ref]ruleThe nodev mount option can be used to prevent device files from
being created in /var/log.
Legitimate character and block devices should exist only in
the /dev directory on the root partition or within chroot
jails built for system services.
Add the nodev option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/log. Rationale:The only legitimate location for device files is the /dev directory
located on the root partition. The only exception to this is chroot jails. Identifiers:
CCE-92589-1 References:
CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, SLES-15-150150435 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/var/log" > /dev/null || findmnt --fstab "/var/log" > /dev/null; }; then
function perform_remediation {
# the mount point /var/log has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/log")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/var/log' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /var/log in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/log)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /var/log defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nodev"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
fi
if mkdir -p "/var/log"; then
if mountpoint -q "/var/log"; then
mount -o remount --target "/var/log"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92589-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/log: Check information associated to mountpoint'
command: findmnt --fstab '/var/log'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-92589-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/log: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-92589-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/log: If /var/log not mounted, craft mount_info manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /var/log
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-92589-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/log: Make sure nodev option is part of the to /var/log
options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "nodev" not in mount_info.options
tags:
- CCE-92589-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/log: Ensure /var/log is mounted with nodev option'
mount:
path: /var/log
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-92589-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_nodev
- no_reboot_needed
|
Add noexec Option to /var/log
[ref]ruleThe noexec mount option can be used to prevent binaries
from being executed out of /var/log.
Add the noexec option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/log. Rationale:Allowing users to execute binaries from directories containing log files
such as /var/log should never be necessary in normal operation and
can expose the system to potential compromise. Identifiers:
CCE-91274-1 References:
CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, R28, SLES-15-150150465 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/var/log" > /dev/null || findmnt --fstab "/var/log" > /dev/null; }; then
function perform_remediation {
# the mount point /var/log has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/log")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/var/log' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /var/log in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/log)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /var/log defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "noexec"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
fi
if mkdir -p "/var/log"; then
if mountpoint -q "/var/log"; then
mount -o remount --target "/var/log"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91274-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/log: Check information associated to mountpoint'
command: findmnt --fstab '/var/log'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-91274-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/log: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-91274-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/log: If /var/log not mounted, craft mount_info
manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /var/log
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-91274-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/log: Make sure noexec option is part of the to
/var/log options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "noexec" not in mount_info.options
tags:
- CCE-91274-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/log: Ensure /var/log is mounted with noexec option'
mount:
path: /var/log
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-91274-1
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_noexec
- no_reboot_needed
|
Add nosuid Option to /var/log
[ref]ruleThe nosuid mount option can be used to prevent
execution of setuid programs in /var/log. The SUID and SGID permissions
should not be required in directories containing log files.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/log. Rationale:The presence of SUID and SGID executables should be tightly controlled. Users
should not be able to execute SUID or SGID binaries from partitions
designated for log files. Identifiers:
CCE-91275-8 References:
CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, R28, SLES-15-150150450 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/var/log" > /dev/null || findmnt --fstab "/var/log" > /dev/null; }; then
function perform_remediation {
# the mount point /var/log has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/log")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/var/log' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /var/log in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/log)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /var/log defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nosuid"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
fi
if mkdir -p "/var/log"; then
if mountpoint -q "/var/log"; then
mount -o remount --target "/var/log"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91275-8
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/log: Check information associated to mountpoint'
command: findmnt --fstab '/var/log'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-91275-8
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/log: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-91275-8
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/log: If /var/log not mounted, craft mount_info
manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /var/log
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-91275-8
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/log: Make sure nosuid option is part of the to
/var/log options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "nosuid" not in mount_info.options
tags:
- CCE-91275-8
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/log: Ensure /var/log is mounted with nosuid option'
mount:
path: /var/log
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/log" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-91275-8
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_log_nosuid
- no_reboot_needed
|
Add nodev Option to /var
[ref]ruleThe nodev mount option can be used to prevent device files from
being created in /var.
Legitimate character and block devices should exist only in
the /dev directory on the root partition or within chroot
jails built for system services.
Add the nodev option to the fourth column of
/etc/fstab for the line which controls mounting of
/var. Rationale:The only legitimate location for device files is the /dev directory
located on the root partition. The only exception to this is chroot jails. Identifiers:
CCE-92590-9 References:
CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, SLES-15-150150330 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/var" > /dev/null || findmnt --fstab "/var" > /dev/null; }; then
function perform_remediation {
# the mount point /var has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/var' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /var in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /var defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nodev"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
fi
if mkdir -p "/var"; then
if mountpoint -q "/var"; then
mount -o remount --target "/var"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92590-9
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var: Check information associated to mountpoint'
command: findmnt --fstab '/var'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-92590-9
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-92590-9
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var: If /var not mounted, craft mount_info manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /var
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-92590-9
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var: Make sure nodev option is part of the to /var options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "nodev" not in mount_info.options
tags:
- CCE-92590-9
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var: Ensure /var is mounted with nodev option'
mount:
path: /var
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-92590-9
- NIST-800-53-AC-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-MP-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_nodev
- no_reboot_needed
|
Add nosuid Option to /var
[ref]ruleThe nosuid mount option can be used to prevent
execution of setuid programs in /var. The SUID and SGID permissions
should not be required for this directory.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/var. Rationale:The presence of SUID and SGID executables should be tightly controlled. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/var" > /dev/null || findmnt --fstab "/var" > /dev/null; }; then
function perform_remediation {
# the mount point /var has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/var' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /var in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /var defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nosuid"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
fi
if mkdir -p "/var"; then
if mountpoint -q "/var"; then
mount -o remount --target "/var"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91277-4
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var: Check information associated to mountpoint'
command: findmnt --fstab '/var'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-91277-4
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-91277-4
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var: If /var not mounted, craft mount_info manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /var
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-91277-4
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var: Make sure nosuid option is part of the to /var
options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "nosuid" not in mount_info.options
tags:
- CCE-91277-4
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var: Ensure /var is mounted with nosuid option'
mount:
path: /var
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-91277-4
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_nosuid
- no_reboot_needed
|
Add nodev Option to /var/tmp
[ref]ruleThe nodev mount option can be used to prevent device files from
being created in /var/tmp. Legitimate character and block devices
should not exist within temporary directories like /var/tmp.
Add the nodev option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/tmp. Rationale:The only legitimate location for device files is the /dev directory
located on the root partition. The only exception to this is chroot jails. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/var/tmp" > /dev/null || findmnt --fstab "/var/tmp" > /dev/null; }; then
function perform_remediation {
# the mount point /var/tmp has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/tmp")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/var/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /var/tmp in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/tmp)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /var/tmp defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nodev"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
fi
if mkdir -p "/var/tmp"; then
if mountpoint -q "/var/tmp"; then
mount -o remount --target "/var/tmp"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92459-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/tmp: Check information associated to mountpoint'
command: findmnt --fstab '/var/tmp'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-92459-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/tmp: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-92459-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/tmp: If /var/tmp not mounted, craft mount_info manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /var/tmp
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-92459-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/tmp: Make sure nodev option is part of the to /var/tmp
options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nodev''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "nodev" not in mount_info.options
tags:
- CCE-92459-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_nodev
- no_reboot_needed
- name: 'Add nodev Option to /var/tmp: Ensure /var/tmp is mounted with nodev option'
mount:
path: /var/tmp
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-92459-7
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_nodev
- no_reboot_needed
|
Add noexec Option to /var/tmp
[ref]ruleThe noexec mount option can be used to prevent binaries
from being executed out of /var/tmp.
Add the noexec option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/tmp. Rationale:Allowing users to execute binaries from world-writable directories
such as /var/tmp should never be necessary in normal operation and
can expose the system to potential compromise. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/var/tmp" > /dev/null || findmnt --fstab "/var/tmp" > /dev/null; }; then
function perform_remediation {
# the mount point /var/tmp has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/tmp")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/var/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /var/tmp in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/tmp)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /var/tmp defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "noexec"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
fi
if mkdir -p "/var/tmp"; then
if mountpoint -q "/var/tmp"; then
mount -o remount --target "/var/tmp"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91278-2
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/tmp: Check information associated to mountpoint'
command: findmnt --fstab '/var/tmp'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-91278-2
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/tmp: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-91278-2
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/tmp: If /var/tmp not mounted, craft mount_info
manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /var/tmp
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-91278-2
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/tmp: Make sure noexec option is part of the to
/var/tmp options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',noexec''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "noexec" not in mount_info.options
tags:
- CCE-91278-2
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_noexec
- no_reboot_needed
- name: 'Add noexec Option to /var/tmp: Ensure /var/tmp is mounted with noexec option'
mount:
path: /var/tmp
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-91278-2
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_noexec
- no_reboot_needed
|
Add nosuid Option to /var/tmp
[ref]ruleThe nosuid mount option can be used to prevent
execution of setuid programs in /var/tmp. The SUID and SGID permissions
should not be required in these world-writable directories.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/var/tmp. Rationale:The presence of SUID and SGID executables should be tightly controlled. Users
should not be able to execute SUID or SGID binaries from temporary storage partitions. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { findmnt --kernel "/var/tmp" > /dev/null || findmnt --fstab "/var/tmp" > /dev/null; }; then
function perform_remediation {
# the mount point /var/tmp has to be defined in /etc/fstab
# before this remediation can be executed. In case it is not defined, the
# remediation aborts and no changes regarding the mount point are done.
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/tmp")"
grep "$mount_point_match_regexp" -q /etc/fstab \
|| { echo "The mount point '/var/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
echo "Not remediating, because there is no record of /var/tmp in /etc/fstab" >&2; return 1; }
mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/tmp)"
# If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
# runtime opts without some automatic kernel/userspace-added defaults
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 | awk '{print $4}' \
| sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
[ "$previous_mount_opts" ] && previous_mount_opts+=","
# In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
# fstab as "block". The next variable is to satisfy shellcheck SC2050.
fs_type=""
if [ "$fs_type" == "iso9660" ] ; then
previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
fi
echo " /var/tmp defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
# If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nosuid"; then
previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
fi
if mkdir -p "/var/tmp"; then
if mountpoint -q "/var/tmp"; then
mount -o remount --target "/var/tmp"
fi
fi
}
perform_remediation
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91279-0
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/tmp: Check information associated to mountpoint'
command: findmnt --fstab '/var/tmp'
register: device_name
failed_when: device_name.rc > 1
changed_when: false
check_mode: false
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
tags:
- CCE-91279-0
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/tmp: Create mount_info dictionary variable'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- '{{ device_name.stdout_lines[0].split() | list | lower }}'
- '{{ device_name.stdout_lines[1].split() | list }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length > 0)
tags:
- CCE-91279-0
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/tmp: If /var/tmp not mounted, craft mount_info
manually'
set_fact:
mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
with_together:
- - target
- source
- fstype
- options
- - /var/tmp
- ''
- ''
- defaults
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
- ("--fstab" | length == 0)
- device_name.stdout is defined and device_name.stdout_lines is defined
- (device_name.stdout | length == 0)
tags:
- CCE-91279-0
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/tmp: Make sure nosuid option is part of the to
/var/tmp options'
set_fact:
mount_info: '{{ mount_info | combine( {''options'':''''~mount_info.options~'',nosuid''
}) }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined and "nosuid" not in mount_info.options
tags:
- CCE-91279-0
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_nosuid
- no_reboot_needed
- name: 'Add nosuid Option to /var/tmp: Ensure /var/tmp is mounted with nosuid option'
mount:
path: /var/tmp
src: '{{ mount_info.source }}'
opts: '{{ mount_info.options }}'
state: mounted
fstype: '{{ mount_info.fstype }}'
when:
- ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
["docker", "lxc", "openvz", "podman", "container"] ) )
- '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
- mount_info is defined
- (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
| length == 0)
tags:
- CCE-91279-0
- configure_strategy
- high_disruption
- low_complexity
- medium_severity
- mount_option_var_tmp_nosuid
- no_reboot_needed
|
Restrict Programs from Dangerous Execution Patterns
[ref]groupThe recommendations in this section are designed to
ensure that the system's features to protect against potentially
dangerous program execution are activated.
These protections are applied at the system initialization or
kernel level, and defend against certain types of badly-configured
or compromised programs. |
| contains 5 rules |
Disable Core Dumps
[ref]groupA core dump file is the memory image of an executable
program when it was terminated by the operating system due to
errant behavior. In most cases, only software developers
legitimately need to access these files. The core dump files may
also contain sensitive information, or unnecessarily occupy large
amounts of disk space.
Once a hard limit is set in /etc/security/limits.conf, or
to a file within the /etc/security/limits.d/ directory, a
user cannot increase that limit within his or her own session. If access
to core dumps is required, consider restricting them to only
certain users or groups. See the limits.conf man page for more
information.
The core dumps of setuid programs are further protected. The
sysctl variable fs.suid_dumpable controls whether
the kernel allows core dumps from these programs at all. The default
value of 0 is recommended. |
| contains 4 rules |
Disable core dump backtraces
[ref]ruleThe ProcessSizeMax option in [Coredump] section
of /etc/systemd/coredump.conf or in a drop-in file under
/etc/systemd/coredump.conf.d/ specifies the maximum size in bytes
of a core which will be processed. Core dumps exceeding this size may be
stored, but the backtrace will not be generated. Warning:
If the /etc/systemd/coredump.conf file or a drop-in file under /etc/systemd/coredump.conf.d/
does not already contain the [Coredump] section,
the value will not be configured correctly. Rationale:A core dump includes a memory image taken at the time the operating system
terminates an application. The memory image could contain sensitive data
and is generally useful only for developers or system operators trying to
debug problems.
Enabling core dumps on production systems is not recommended,
however there may be overriding operational requirements to enable advanced
debugging. Permitting temporary enablement of core dumps during such situations
should be reviewed through local needs and policy. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q systemd; }; then
found=false
# set value in all files if they contain section or key
for f in $(echo -n "/etc/systemd/coredump.conf.d/complianceascode_hardening.conf /etc/systemd/coredump.conf.d/*.conf /etc/systemd/coredump.conf"); do
if [ ! -e "$f" ]; then
continue
fi
# find key in section and change value
if grep -qzosP "[[:space:]]*\[Coredump\]([^\n\[]*\n+)+?[[:space:]]*ProcessSizeMax" "$f"; then
if ! grep -qPz "ProcessSizeMax=0" "$f"; then
sed -i "s/ProcessSizeMax[^(\n)]*/ProcessSizeMax=0/" "$f"
fi
found=true
# find section and add key = value to it
elif grep -qs "[[:space:]]*\[Coredump\]" "$f"; then
sed -i "/[[:space:]]*\[Coredump\]/a ProcessSizeMax=0" "$f"
found=true
fi
done
# if section not in any file, append section with key = value to FIRST file in files parameter
if ! $found ; then
file=$(echo "/etc/systemd/coredump.conf.d/complianceascode_hardening.conf /etc/systemd/coredump.conf.d/*.conf /etc/systemd/coredump.conf" | cut -f1 -d ' ')
mkdir -p "$(dirname "$file")"
echo -e "[Coredump]\nProcessSizeMax=0" >> "$file"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85745-8
- NIST-800-53-CM-6
- PCI-DSS-Req-3.2
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- coredump_disable_backtraces
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable core dump backtraces - Search for a section in files
ansible.builtin.find:
paths: '{{item.path}}'
patterns: '{{item.pattern}}'
contains: ^\s*\[Coredump\]
read_whole_file: true
use_regex: true
register: systemd_dropin_files_with_section
loop:
- path: '{{ ''/etc/systemd/coredump.conf'' | dirname }}'
pattern: '{{ ''/etc/systemd/coredump.conf'' | basename | regex_escape }}'
- path: /etc/systemd/coredump.conf.d
pattern: .*\.conf
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
tags:
- CCE-85745-8
- NIST-800-53-CM-6
- PCI-DSS-Req-3.2
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- coredump_disable_backtraces
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable core dump backtraces - Count number of files which contain the correct
section
ansible.builtin.set_fact:
count_of_systemd_dropin_files_with_section: '{{systemd_dropin_files_with_section.results
| map(attribute=''matched'') | list | map(''int'') | sum}}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
tags:
- CCE-85745-8
- NIST-800-53-CM-6
- PCI-DSS-Req-3.2
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- coredump_disable_backtraces
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable core dump backtraces - Add missing configuration to correct section
community.general.ini_file:
path: '{{item}}'
section: Coredump
option: ProcessSizeMax
value: '0'
state: present
no_extra_spaces: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
- count_of_systemd_dropin_files_with_section | int > 0
loop: '{{systemd_dropin_files_with_section.results | sum(attribute=''files'', start=[])
| map(attribute=''path'') | list }}'
tags:
- CCE-85745-8
- NIST-800-53-CM-6
- PCI-DSS-Req-3.2
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- coredump_disable_backtraces
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable core dump backtraces - Add configuration to new remediation file
community.general.ini_file:
path: /etc/systemd/coredump.conf.d/complianceascode_hardening.conf
section: Coredump
option: ProcessSizeMax
value: '0'
state: present
no_extra_spaces: true
create: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
- count_of_systemd_dropin_files_with_section | int == 0
tags:
- CCE-85745-8
- NIST-800-53-CM-6
- PCI-DSS-Req-3.2
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- coredump_disable_backtraces
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Disable storing core dump
[ref]ruleThe Storage option in [Coredump] section
of /etc/systemd/coredump.conf or a drop-in file in
/etc/systemd/coredump.conf.d/*.conf
can be set to none to disable storing core dumps permanently. Warning:
If the /etc/systemd/coredump.conf file or a drop-in file under /etc/systemd/coredump.conf.d/
does not already contain the [Coredump] section,
the value will not be configured correctly. Rationale:A core dump includes a memory image taken at the time the operating system
terminates an application. The memory image could contain sensitive data
and is generally useful only for developers or system operators trying to
debug problems. Enabling core dumps on production systems is not recommended,
however there may be overriding operational requirements to enable advanced
debugging. Permitting temporary enablement of core dumps during such situations
should be reviewed through local needs and policy. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q systemd; }; then
found=false
# set value in all files if they contain section or key
for f in $(echo -n "/etc/systemd/coredump.conf.d/complianceascode_hardening.conf /etc/systemd/coredump.conf.d/*.conf /etc/systemd/coredump.conf"); do
if [ ! -e "$f" ]; then
continue
fi
# find key in section and change value
if grep -qzosP "[[:space:]]*\[Coredump\]([^\n\[]*\n+)+?[[:space:]]*Storage" "$f"; then
if ! grep -qPz "Storage=none" "$f"; then
sed -i "s/Storage[^(\n)]*/Storage=none/" "$f"
fi
found=true
# find section and add key = value to it
elif grep -qs "[[:space:]]*\[Coredump\]" "$f"; then
sed -i "/[[:space:]]*\[Coredump\]/a Storage=none" "$f"
found=true
fi
done
# if section not in any file, append section with key = value to FIRST file in files parameter
if ! $found ; then
file=$(echo "/etc/systemd/coredump.conf.d/complianceascode_hardening.conf /etc/systemd/coredump.conf.d/*.conf /etc/systemd/coredump.conf" | cut -f1 -d ' ')
mkdir -p "$(dirname "$file")"
echo -e "[Coredump]\nStorage=none" >> "$file"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85746-6
- NIST-800-53-CM-6
- PCI-DSS-Req-3.2
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- coredump_disable_storage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable storing core dump - Search for a section in files
ansible.builtin.find:
paths: '{{item.path}}'
patterns: '{{item.pattern}}'
contains: ^\s*\[Coredump\]
read_whole_file: true
use_regex: true
register: systemd_dropin_files_with_section
loop:
- path: '{{ ''/etc/systemd/coredump.conf'' | dirname }}'
pattern: '{{ ''/etc/systemd/coredump.conf'' | basename | regex_escape }}'
- path: /etc/systemd/coredump.conf.d
pattern: .*\.conf
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
tags:
- CCE-85746-6
- NIST-800-53-CM-6
- PCI-DSS-Req-3.2
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- coredump_disable_storage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable storing core dump - Count number of files which contain the correct
section
ansible.builtin.set_fact:
count_of_systemd_dropin_files_with_section: '{{systemd_dropin_files_with_section.results
| map(attribute=''matched'') | list | map(''int'') | sum}}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
tags:
- CCE-85746-6
- NIST-800-53-CM-6
- PCI-DSS-Req-3.2
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- coredump_disable_storage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable storing core dump - Add missing configuration to correct section
community.general.ini_file:
path: '{{item}}'
section: Coredump
option: Storage
value: none
state: present
no_extra_spaces: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
- count_of_systemd_dropin_files_with_section | int > 0
loop: '{{systemd_dropin_files_with_section.results | sum(attribute=''files'', start=[])
| map(attribute=''path'') | list }}'
tags:
- CCE-85746-6
- NIST-800-53-CM-6
- PCI-DSS-Req-3.2
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- coredump_disable_storage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable storing core dump - Add configuration to new remediation file
community.general.ini_file:
path: /etc/systemd/coredump.conf.d/complianceascode_hardening.conf
section: Coredump
option: Storage
value: none
state: present
no_extra_spaces: true
create: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
- count_of_systemd_dropin_files_with_section | int == 0
tags:
- CCE-85746-6
- NIST-800-53-CM-6
- PCI-DSS-Req-3.2
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- coredump_disable_storage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Disable Core Dumps for All Users
[ref]ruleTo disable core dumps for all users, add the following line to
/etc/security/limits.conf, or to a file within the
/etc/security/limits.d/ directory:
* hard core 0 Rationale:A core dump includes a memory image taken at the time the operating system
terminates an application. The memory image could contain sensitive data and is generally useful
only for developers trying to debug problems. Identifiers:
CCE-85740-9 References:
1, 12, 13, 15, 16, 2, 7, 8, APO13.01, BAI04.04, DSS01.03, DSS03.05, DSS05.07, SR 6.2, SR 7.1, SR 7.2, A.12.1.3, A.17.2.1, CM-6, SC-7(10), DE.CM-1, PR.DS-4, SRG-OS-000480-GPOS-00227, 1.6.1, SLES-15-150750030, 3.3.1.1, 3.3.1, 3.3 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q pam; }; then
SECURITY_LIMITS_FILE="/etc/security/limits.conf"
DROPIN_DIR="/etc/security/limits.d"
DROPIN_FILE="$DROPIN_DIR/10-ssg-hardening.conf"
REGEX_CORRECT_VALUE="^\s*\*\s+hard\s+core\s+0\s*$"
# Remove bad configuration in drop-ins
if [ -d "$DROPIN_DIR" ]; then
for override in "$DROPIN_DIR"/*.conf; do
if [ -f "$override" ] && ! grep -qE "$REGEX_CORRECT_VALUE" "$override"; then
sed -ir -E '/^[[:space:]]*\*[[:space:]]+hard[[:space:]]+core[[:space:]]+/ s/^/#/' "$override"
fi
done
fi
if [ -d "$DROPIN_DIR" ] && grep -qEr "$REGEX_CORRECT_VALUE" "$DROPIN_DIR"; then
exit 0
elif [ ! -d "$DROPIN_DIR" ] && grep -qE "$REGEX_CORRECT_VALUE" "$SECURITY_LIMITS_FILE"; then
exit 0
else
mkdir -p "$DROPIN_DIR"
echo "* hard core 0" >> $DROPIN_FILE
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85740-9
- NIST-800-53-CM-6
- NIST-800-53-SC-7(10)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_users_coredumps
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable Core Dumps for All Users - Set dirs, files and regex variables
ansible.builtin.set_fact:
limits_dropin_dir: /etc/security/limits.d
limits_dropin_file: /etc/security/limits.d/10-ssg-hardening.conf
limits_main_file: /etc/security/limits.conf
limits_correct_regex: ^\s*\*\s+hard\s+core\s+0\s*$
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
tags:
- CCE-85740-9
- NIST-800-53-CM-6
- NIST-800-53-SC-7(10)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_users_coredumps
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable Core Dumps for All Users - Find valid drop-ins for core limit
ansible.builtin.find:
paths: '{{ limits_dropin_dir }}'
patterns: '*.conf'
contains: '{{ limits_correct_regex }}'
file_type: file
register: valid_dropins
failed_when: false
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
tags:
- CCE-85740-9
- NIST-800-53-CM-6
- NIST-800-53-SC-7(10)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_users_coredumps
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable Core Dumps for All Users - Find all drop-ins with any core limit
ansible.builtin.find:
paths: '{{ limits_dropin_dir }}'
patterns: '*.conf'
contains: ^\s*\*\s+hard\s+core\s+
file_type: file
register: all_dropins
failed_when: false
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
tags:
- CCE-85740-9
- NIST-800-53-CM-6
- NIST-800-53-SC-7(10)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_users_coredumps
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable Core Dumps for All Users - Get invalid drop-ins
ansible.builtin.set_fact:
invalid_dropins: '{{ all_dropins.files | rejectattr(''path'', ''in'', valid_dropins.files
| map(attribute=''path'') | list) | map(attribute=''path'') | list }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
tags:
- CCE-85740-9
- NIST-800-53-CM-6
- NIST-800-53-SC-7(10)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_users_coredumps
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable Core Dumps for All Users - Comment invalid * hard core lines in drop-ins
ansible.builtin.replace:
path: '{{ item }}'
regexp: (^\s*\*\s+hard\s+core\s+.*$)
replace: '#\1'
loop: '{{ invalid_dropins }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
- invalid_dropins | length > 0
tags:
- CCE-85740-9
- NIST-800-53-CM-6
- NIST-800-53-SC-7(10)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_users_coredumps
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable Core Dumps for All Users - Check if main limits.conf contains correct
core limit
ansible.builtin.find:
paths: /etc/security
patterns: limits.conf
contains: '{{ limits_correct_regex }}'
file_type: file
register: main_valid
failed_when: false
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
- not (valid_dropins.matched | default(0) > 0)
tags:
- CCE-85740-9
- NIST-800-53-CM-6
- NIST-800-53-SC-7(10)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_users_coredumps
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable Core Dumps for All Users - Set fact if configuration is valid
ansible.builtin.set_fact:
core_limit_valid: '{{ (valid_dropins.matched | default(0)) > 0 or (main_valid.matched
| default(0)) > 0 }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
tags:
- CCE-85740-9
- NIST-800-53-CM-6
- NIST-800-53-SC-7(10)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_users_coredumps
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable Core Dumps for All Users - Ensure drop-in directory exists
ansible.builtin.file:
path: '{{ limits_dropin_dir }}'
state: directory
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
- not core_limit_valid
tags:
- CCE-85740-9
- NIST-800-53-CM-6
- NIST-800-53-SC-7(10)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_users_coredumps
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable Core Dumps for All Users - Deploy 10-ssg-hardening.conf drop-in with
correct core limit
ansible.builtin.copy:
dest: '{{ limits_dropin_file }}'
content: |
* hard core 0
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"pam" in ansible_facts.packages'
- not core_limit_valid
tags:
- CCE-85740-9
- NIST-800-53-CM-6
- NIST-800-53-SC-7(10)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_users_coredumps
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Disable Core Dumps for SUID programs
[ref]ruleTo set the runtime status of the fs.suid_dumpable kernel parameter, run the following command: $ sudo sysctl -w fs.suid_dumpable=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: fs.suid_dumpable = 0 Rationale:The core dump of a setuid program is more likely to contain
sensitive data, as the program itself runs with greater privileges than the
user who initiated execution of the program. Disabling the ability for any
setuid program to write a core file decreases the risk of unauthorized access
of such data. Identifiers:
CCE-91447-3 References:
164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), SI-11(a), SI-11(b), 1.6.1, R14, SLES-15-150750030, 3.3.1.1, 3.3.1, 3.3 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of fs.suid_dumpable from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*fs.suid_dumpable.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "fs.suid_dumpable" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/fs_suid_dumpable.conf'
#
# Set runtime for fs.suid_dumpable
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w fs.suid_dumpable="0"
fi
#
# If fs.suid_dumpable present in /etc/sysctl.conf, change value to "0"
# else, add "fs.suid_dumpable = 0" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^fs.suid_dumpable")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^fs.suid_dumpable\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^fs.suid_dumpable\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-91447-3"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91447-3
- NIST-800-53-SI-11(a)
- NIST-800-53-SI-11(b)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_suid_dumpable
- name: Disable Core Dumps for SUID programs - Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91447-3
- NIST-800-53-SI-11(a)
- NIST-800-53-SI-11(b)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_suid_dumpable
- name: Disable Core Dumps for SUID programs - Find all files that contain fs.suid_dumpable
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*fs.suid_dumpable\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91447-3
- NIST-800-53-SI-11(a)
- NIST-800-53-SI-11(b)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_suid_dumpable
- name: Disable Core Dumps for SUID programs - Find all files that set fs.suid_dumpable
to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*fs.suid_dumpable\s*=\s*0$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91447-3
- NIST-800-53-SI-11(a)
- NIST-800-53-SI-11(b)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_suid_dumpable
- name: Disable Core Dumps for SUID programs - Comment out any occurrences of fs.suid_dumpable
from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*fs.suid_dumpable
replace: '#fs.suid_dumpable'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-91447-3
- NIST-800-53-SI-11(a)
- NIST-800-53-SI-11(b)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_suid_dumpable
- name: Disable Core Dumps for SUID programs - Comment out any occurrences of fs.suid_dumpable
from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*fs.suid_dumpable
replace: '#fs.suid_dumpable'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91447-3
- NIST-800-53-SI-11(a)
- NIST-800-53-SI-11(b)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_suid_dumpable
- name: Disable Core Dumps for SUID programs - Ensure sysctl fs.suid_dumpable is set
to 0
ansible.posix.sysctl:
name: fs.suid_dumpable
value: '0'
sysctl_file: /etc/sysctl.d/fs_suid_dumpable.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91447-3
- NIST-800-53-SI-11(a)
- NIST-800-53-SI-11(b)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_suid_dumpable
|
Enable ExecShield
[ref]groupExecShield describes kernel features that provide
protection against exploitation of memory corruption errors such as buffer
overflows. These features include random placement of the stack and other
memory regions, prevention of execution in memory that should only hold data,
and special handling of text buffers. These protections are enabled by default
on 32-bit systems and controlled through sysctl variables
kernel.exec-shield and kernel.randomize_va_space. On the latest
64-bit systems, kernel.exec-shield cannot be enabled or disabled with
sysctl. |
| contains 1 rule |
Enable Randomized Layout of Virtual Address Space
[ref]ruleTo set the runtime status of the kernel.randomize_va_space kernel parameter, run the following command: $ sudo sysctl -w kernel.randomize_va_space=2
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: kernel.randomize_va_space = 2 Rationale:Address space layout randomization (ASLR) makes it more difficult for an
attacker to predict the location of attack code they have introduced into a
process's address space during an attempt at exploitation. Additionally,
ASLR makes it more difficult for an attacker to know the location of
existing code in order to re-purpose it using return oriented programming
(ROP) techniques. Identifiers:
CCE-83300-4 References:
3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), CIP-002-5 R1.1, CIP-002-5 R1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 4.1, CIP-004-6 4.2, CIP-004-6 R2.2.3, CIP-004-6 R2.2.4, CIP-004-6 R2.3, CIP-004-6 R4, CIP-005-6 R1, CIP-005-6 R1.1, CIP-005-6 R1.2, CIP-007-3 R3, CIP-007-3 R3.1, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, CIP-007-3 R8.4, CIP-009-6 R.1.1, CIP-009-6 R4, SC-30, SC-30(2), CM-6(a), Req-2.2.1, SRG-OS-000433-GPOS-00193, SRG-OS-000480-GPOS-00227, SRG-APP-000450-CTR-001105, SLES-15-010550, 1.6.3, R9, SLES-15-150750015, 1409, 3.3.1.1, 3.3.1, 3.3, SV-234862r958928_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Comment out any occurrences of kernel.randomize_va_space from /etc/sysctl.d/*.conf files
for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf; do
# skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi
matching_list=$(grep -P '^(?!#).*[\s]*kernel.randomize_va_space.*$' $f | uniq )
if ! test -z "$matching_list"; then
while IFS= read -r entry; do
escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
# comment out "kernel.randomize_va_space" matches to preserve user data
sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
done <<< "$matching_list"
fi
done
#
# Set sysctl config file which to save the desired value
#
SYSCONFIG_FILE='/etc/sysctl.d/kernel_randomize_va_space.conf'
#
# Set runtime for kernel.randomize_va_space
#
if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
/sbin/sysctl -q -n -w kernel.randomize_va_space="2"
fi
#
# If kernel.randomize_va_space present in /etc/sysctl.conf, change value to "2"
# else, add "kernel.randomize_va_space = 2" to /etc/sysctl.conf
#
sed -i "/^$SYSCONFIG_VAR/d" /etc/sysctl.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^kernel.randomize_va_space")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "2"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^kernel.randomize_va_space\\>" "${SYSCONFIG_FILE}"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^kernel.randomize_va_space\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
fi
cce="CCE-83300-4"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "${SYSCONFIG_FILE}" >> "${SYSCONFIG_FILE}"
printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83300-4
- DISA-STIG-SLES-15-010550
- NIST-800-171-3.1.7
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-30
- NIST-800-53-SC-30(2)
- PCI-DSS-Req-2.2.1
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_kernel_randomize_va_space
- name: Enable Randomized Layout of Virtual Address Space - Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /run/sysctl.d/
- /etc/sysctl.d/
- /usr/local/lib/sysctl.d/
- /lib/sysctl.d/
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83300-4
- DISA-STIG-SLES-15-010550
- NIST-800-171-3.1.7
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-30
- NIST-800-53-SC-30(2)
- PCI-DSS-Req-2.2.1
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_kernel_randomize_va_space
- name: Enable Randomized Layout of Virtual Address Space - Find all files that contain
kernel.randomize_va_space
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*kernel.randomize_va_space\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83300-4
- DISA-STIG-SLES-15-010550
- NIST-800-171-3.1.7
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-30
- NIST-800-53-SC-30(2)
- PCI-DSS-Req-2.2.1
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_kernel_randomize_va_space
- name: Enable Randomized Layout of Virtual Address Space - Find all files that set
kernel.randomize_va_space to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*kernel.randomize_va_space\s*=\s*2$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83300-4
- DISA-STIG-SLES-15-010550
- NIST-800-171-3.1.7
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-30
- NIST-800-53-SC-30(2)
- PCI-DSS-Req-2.2.1
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_kernel_randomize_va_space
- name: Enable Randomized Layout of Virtual Address Space - Comment out any occurrences
of kernel.randomize_va_space from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*kernel.randomize_va_space
replace: '#kernel.randomize_va_space'
loop: '{{ find_all_values.stdout_lines }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
| length > find_correct_value.stdout_lines | length
tags:
- CCE-83300-4
- DISA-STIG-SLES-15-010550
- NIST-800-171-3.1.7
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-30
- NIST-800-53-SC-30(2)
- PCI-DSS-Req-2.2.1
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_kernel_randomize_va_space
- name: Enable Randomized Layout of Virtual Address Space - Comment out any occurrences
of kernel.randomize_va_space from /etc/sysctl.conf
ansible.builtin.replace:
path: /etc/sysctl.conf
regexp: ^[\s]*kernel.randomize_va_space
replace: '#kernel.randomize_va_space'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83300-4
- DISA-STIG-SLES-15-010550
- NIST-800-171-3.1.7
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-30
- NIST-800-53-SC-30(2)
- PCI-DSS-Req-2.2.1
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_kernel_randomize_va_space
- name: Enable Randomized Layout of Virtual Address Space - Ensure sysctl kernel.randomize_va_space
is set to 2
ansible.posix.sysctl:
name: kernel.randomize_va_space
value: '2'
sysctl_file: /etc/sysctl.d/kernel_randomize_va_space.conf
state: present
reload: true
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83300-4
- DISA-STIG-SLES-15-010550
- NIST-800-171-3.1.7
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-30
- NIST-800-53-SC-30(2)
- PCI-DSS-Req-2.2.1
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_kernel_randomize_va_space
|
SELinux
[ref]groupSELinux is a feature of the Linux kernel which can be
used to guard against misconfigured or compromised programs.
SELinux enforces the idea that programs should be limited in what
files they can access and what actions they can take.
The default SELinux policy, as configured on SUSE Linux Enterprise 15, has been
sufficiently developed and debugged that it should be usable on
almost any system with minimal configuration and a small
amount of system administrator training. This policy prevents
system services - including most of the common network-visible
services such as mail servers, FTP servers, and DNS servers - from
accessing files which those services have no valid reason to
access. This action alone prevents a huge amount of possible damage
from network attacks against services, from trojaned software, and
so forth.
This guide recommends that SELinux be enabled using the
default (targeted) policy on every SUSE Linux Enterprise 15 system, unless that
system has unusual requirements which make a stronger policy
appropriate. |
| contains 3 rules |
Verify Group Who Owns /etc/selinux Directory
[ref]rule To properly set the group owner of /etc/selinux, run the command:
$ sudo chgrp root /etc/selinux
Rationale:The ownership of the /etc/selinux directory by the root group is important
because this directory hosts SELinux configuration. Protection of this
directory is critical for system security. Assigning the ownership to root
ensures exclusive control of the SELinux configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newgroup=""
if getent group "root" >/dev/null 2>&1; then
newgroup="root"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "root is not a defined group on the system"
else
find -P /etc/selinux/ -maxdepth 0 -type d ! -group root -exec chgrp --no-dereference "$newgroup" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92501-6
- configure_strategy
- directory_groupowner_etc_selinux
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Check that the root group is defined
ansible.builtin.getent:
database: group
key: root
ignore_errors: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- directory_groupowner_etc_selinux_newgroup is undefined
tags:
- CCE-92501-6
- configure_strategy
- directory_groupowner_etc_selinux
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the directory_groupowner_etc_selinux_newgroup variable if root found
ansible.builtin.set_fact:
directory_groupowner_etc_selinux_newgroup: root
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_facts.getent_group["root"] is defined
tags:
- CCE-92501-6
- configure_strategy
- directory_groupowner_etc_selinux
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/selinux/
ansible.builtin.file:
path: /etc/selinux/
follow: false
state: directory
group: '{{ directory_groupowner_etc_selinux_newgroup }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92501-6
- configure_strategy
- directory_groupowner_etc_selinux
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns /etc/selinux Directory
[ref]rule To properly set the owner of /etc/selinux, run the command:
$ sudo chown root /etc/selinux
Rationale:The ownership of the /etc/selinux directory by the root user is important
because this directory hosts SELinux configuration. Protection of this
directory is critical for system security. Assigning the ownership to root
ensures exclusive control of the SELinux configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
find -P /etc/selinux/ -maxdepth 0 -type d ! -user 0 -exec chown --no-dereference "$newown" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92510-7
- configure_strategy
- directory_owner_etc_selinux
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the directory_owner_etc_selinux_newown variable if represented by uid
ansible.builtin.set_fact:
directory_owner_etc_selinux_newown: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92510-7
- configure_strategy
- directory_owner_etc_selinux
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on directory /etc/selinux/
ansible.builtin.file:
path: /etc/selinux/
follow: false
state: directory
owner: '{{ directory_owner_etc_selinux_newown }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92510-7
- configure_strategy
- directory_owner_etc_selinux
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions On /etc/selinux Directory
[ref]rule To properly set the permissions of /etc/selinux, run the command: $ sudo chmod 0755 /etc/selinux Rationale:Setting correct permissions on the /etc/selinux directory is important
because this directory hosts SELinux configuration. Protection of this
directory is critical for system security. Restricting the permissions
ensures exclusive control of the SELinux configuration. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
find -H /etc/selinux/ -maxdepth 0 -perm /u+s,g+ws,o+wt -type d -exec chmod u-s,g-ws,o-wt {} \;
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92524-8
- configure_strategy
- directory_permissions_etc_selinux
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/selinux/ file(s)
ansible.builtin.command: 'find -P /etc/selinux/ -maxdepth 0 -perm /u+s,g+ws,o+wt -type
d '
register: files_found
changed_when: false
failed_when: false
check_mode: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92524-8
- configure_strategy
- directory_permissions_etc_selinux
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set permissions for /etc/selinux/ file(s)
ansible.builtin.file:
path: '{{ item }}'
mode: u-s,g-ws,o-wt
state: directory
with_items:
- '{{ files_found.stdout_lines }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92524-8
- configure_strategy
- directory_permissions_etc_selinux
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Services
[ref]groupThe best protection against vulnerable software is running less software. This section describes how to review
the software which SUSE Linux Enterprise 15 installs on a system and disable software which is not needed. It
then enumerates the software packages installed on a default SUSE Linux Enterprise 15 system and provides guidance about which
ones can be safely disabled.
SUSE Linux Enterprise 15 provides a convenient minimal install option that essentially installs the bare necessities for a functional
system. When building SUSE Linux Enterprise 15 systems, it is highly recommended to select the minimal packages and then build up
the system from there. |
| contains 114 rules |
Avahi Server
[ref]groupThe Avahi daemon implements the DNS Service Discovery
and Multicast DNS protocols, which provide service and host
discovery on a network. It allows a system to automatically
identify resources on the network, such as printers or web servers.
This capability is also known as mDNSresponder and is a major part
of Zeroconf networking. |
| contains 3 rules |
Disable Avahi Server if Possible
[ref]groupBecause the Avahi daemon service keeps an open network
port, it is subject to network attacks.
Disabling it can reduce the system's vulnerability to such attacks. |
| contains 3 rules |
Uninstall avahi-autoipd Server Package
[ref]ruleIf the system does not need to have an Avahi server which implements
the DNS Service Discovery and Multicast DNS protocols,
the avahi-autoipd and avahi packages can be uninstalled. Rationale:Automatic discovery of network services is not normally required for
system functionality. It is recommended to remove this package to reduce
the potential attack surface. Identifiers:
CCE-92465-4 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.3, SLES-15-300150030 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_avahi-autoipd
class remove_avahi-autoipd {
package { 'avahi-autoipd':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove avahi-autoipd
# from the system, and may remove any packages
# that depend on avahi-autoipd. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "avahi-autoipd"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall avahi-autoipd Server Package: Ensure avahi-autoipd is removed'
ansible.builtin.package:
name: avahi-autoipd
state: absent
tags:
- CCE-92465-4
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_avahi-autoipd_removed
|
Uninstall avahi Server Package
[ref]ruleIf the system does not need to have an Avahi server which implements
the DNS Service Discovery and Multicast DNS protocols,
the avahi-autoipd and avahi packages can be uninstalled. Rationale:Automatic discovery of network services is not normally required for
system functionality. It is recommended to remove this package to reduce
the potential attack surface. Identifiers:
CCE-92464-7 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.3, SLES-15-300150030 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_avahi
class remove_avahi {
package { 'avahi':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove avahi
# from the system, and may remove any packages
# that depend on avahi. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "avahi"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall avahi Server Package: Ensure avahi is removed'
ansible.builtin.package:
name: avahi
state: absent
tags:
- CCE-92464-7
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_avahi_removed
|
Disable Avahi Server Software
[ref]rule
The avahi-daemon service can be disabled with the following command:
$ sudo systemctl mask --now avahi-daemon.service Rationale:Because the Avahi daemon service keeps an open network
port, it is subject to network attacks. Its functionality
is convenient but is only appropriate if the local network
can be trusted. Identifiers:
CCE-91321-0 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.3, SLES-15-300150030, 1409, 2.2.4, 2.2 Remediation script: (show)
[customizations.services]
masked = ["avahi-daemon"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_avahi-daemon
class disable_avahi-daemon {
service {'avahi-daemon':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if ( rpm --quiet -q avahi && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base ); then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'avahi-daemon.service'
fi
"$SYSTEMCTL_EXEC" disable 'avahi-daemon.service'
"$SYSTEMCTL_EXEC" mask 'avahi-daemon.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files avahi-daemon.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'avahi-daemon.socket'
fi
"$SYSTEMCTL_EXEC" mask 'avahi-daemon.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'avahi-daemon.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91321-0
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_avahi-daemon_disabled
- name: Disable Avahi Server Software - Disable service avahi-daemon
block:
- name: Disable Avahi Server Software - Collect systemd Services Present in the
System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable Avahi Server Software - Ensure avahi-daemon.service is Masked
ansible.builtin.systemd:
name: avahi-daemon.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("avahi-daemon.service", multiline=True)
- name: Unit Socket Exists - avahi-daemon.socket
ansible.builtin.command: systemctl -q list-unit-files avahi-daemon.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable Avahi Server Software - Disable Socket avahi-daemon
ansible.builtin.systemd:
name: avahi-daemon.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("avahi-daemon.socket", multiline=True)
tags:
- CCE-91321-0
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_avahi-daemon_disabled
- special_service_block
when: ( "avahi" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
|
Cron and At Daemons
[ref]groupThe cron and at services are used to allow commands to
be executed at a later time. The cron service is required by almost
all systems to perform necessary maintenance tasks, while at may or
may not be required on a given system. Both daemons should be
configured defensively. |
| contains 27 rules |
Restrict at and cron to Authorized Users if Necessary
[ref]groupThe /etc/cron.allow and /etc/at.allow files contain lists of
users who are allowed to use cron and at to delay execution of
processes. If these files exist and if the corresponding files
/etc/cron.deny and /etc/at.deny do not exist, then only users
listed in the relevant allow files can run the crontab and at commands
to submit jobs to be run at scheduled intervals. On many systems, only the
system administrator needs the ability to schedule jobs. Note that even if a
given user is not listed in cron.allow, cron jobs can still be run as
that user. The cron.allow file controls only administrative access
to the crontab command for scheduling and modifying cron jobs.
To restrict at and cron to only authorized users:
- Remove the
cron.deny file:$ sudo rm /etc/cron.deny - Edit
/etc/cron.allow, adding one line for each user allowed to use
the crontab command to create cron jobs. - Remove the
at.deny file:$ sudo rm /etc/at.deny - Edit
/etc/at.allow, adding one line for each user allowed to use
the at command to create at jobs.
|
| contains 9 rules |
Ensure that /etc/at.deny does not exist
[ref]ruleThe file /etc/at.deny should not exist.
Use /etc/at.allow instead. Rationale:Access to at should be restricted.
It is easier to manage an allow list than a deny list. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [[ -f /etc/at.deny ]]; then
rm /etc/at.deny
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91313-7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- disable_strategy
- file_at_deny_not_exist
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure that /etc/at.deny does not exist - Remove /etc/at.deny
ansible.builtin.file:
path: /etc/at.deny
state: absent
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91313-7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- disable_strategy
- file_at_deny_not_exist
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Ensure that /etc/cron.allow exists
[ref]ruleThe file /etc/cron.allow should exist and should be used instead
of /etc/cron.deny. Rationale:Access to crontab should be restricted.
It is easier to manage an allow list than a deny list.
Therefore, /etc/cron.allow needs to be created and used instead of /etc/cron.deny.
Regardless of the existence of any of these files, the root administrative user is always allowed to setup a crontab. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
touch /etc/cron.allow
chown 0 /etc/cron.allow
chmod 0600 /etc/cron.allow
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92533-9
- disable_strategy
- file_cron_allow_exists
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure that /etc/cron.allow exists - Add empty /etc/cron.allow
ansible.builtin.file:
path: /etc/cron.allow
state: touch
owner: '0'
mode: '0600'
modification_time: preserve
access_time: preserve
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92533-9
- disable_strategy
- file_cron_allow_exists
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Ensure that /etc/cron.deny does not exist
[ref]ruleThe file /etc/cron.deny should not exist.
Use /etc/cron.allow instead. Rationale:Access to cron should be restricted.
It is easier to manage an allow list than a deny list. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [[ -f /etc/cron.deny ]]; then
rm /etc/cron.deny
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91314-5
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- disable_strategy
- file_cron_deny_not_exist
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure that /etc/cron.deny does not exist - Remove /etc/cron.deny
ansible.builtin.file:
path: /etc/cron.deny
state: absent
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91314-5
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- disable_strategy
- file_cron_deny_not_exist
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns /etc/at.allow file
[ref]ruleIf /etc/at.allow exists, it must be group-owned by root.
To properly set the group owner of /etc/at.allow, run the command:
$ sudo chgrp root /etc/at.allow
Rationale:If the owner of the at.allow file is not set to root, the possibility exists for an
unauthorized user to view or edit sensitive information. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/at.allow" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/at.allow
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91315-2
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_at_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_groupowner_at_allow_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_at_allow_newgroup: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91315-2
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_at_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/at.allow
ansible.builtin.stat:
path: /etc/at.allow
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91315-2
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_at_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/at.allow
ansible.builtin.file:
path: /etc/at.allow
follow: false
group: '{{ file_groupowner_at_allow_newgroup }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91315-2
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_at_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns /etc/cron.allow file
[ref]ruleIf /etc/cron.allow exists, it must be group-owned by root.
To properly set the group owner of /etc/cron.allow, run the command:
$ sudo chgrp root /etc/cron.allow
Rationale:If the owner of the cron.allow file is not set to root, the possibility exists for an
unauthorized user to view or edit sensitive information. Identifiers:
CCE-91316-0 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.8, SLES-15-300600120, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/cron.allow" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/cron.allow
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91316-0
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_groupowner_cron_allow_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_cron_allow_newgroup: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91316-0
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/cron.allow
ansible.builtin.stat:
path: /etc/cron.allow
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91316-0
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/cron.allow
ansible.builtin.file:
path: /etc/cron.allow
follow: false
group: '{{ file_groupowner_cron_allow_newgroup }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91316-0
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns /etc/at.allow file
[ref]ruleIf /etc/at.allow exists, it must be owned by root.
To properly set the owner of /etc/at.allow, run the command:
$ sudo chown root /etc/at.allow
Rationale:If the owner of the at.allow file is not set to root, the possibility exists for an
unauthorized user to view or edit sensitive information. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/at.allow" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/at.allow
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91317-8
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_at_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_owner_at_allow_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_at_allow_newown: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91317-8
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_at_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/at.allow
ansible.builtin.stat:
path: /etc/at.allow
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91317-8
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_at_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/at.allow
ansible.builtin.file:
path: /etc/at.allow
follow: false
owner: '{{ file_owner_at_allow_newown }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91317-8
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_at_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify User Who Owns /etc/cron.allow file
[ref]ruleIf /etc/cron.allow exists, it must be owned by root.
To properly set the owner of /etc/cron.allow, run the command:
$ sudo chown root /etc/cron.allow
Rationale:If the owner of the cron.allow file is not set to root, the possibility exists for an
unauthorized user to view or edit sensitive information. Identifiers:
CCE-91318-6 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.8, SLES-15-300600120, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/cron.allow" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/cron.allow
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91318-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_owner_cron_allow_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_cron_allow_newown: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91318-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/cron.allow
ansible.builtin.stat:
path: /etc/cron.allow
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91318-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/cron.allow
ansible.builtin.file:
path: /etc/cron.allow
follow: false
owner: '{{ file_owner_cron_allow_newown }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91318-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on /etc/at.allow file
[ref]ruleIf /etc/at.allow exists, it must have permissions 0640
or more restrictive.
To properly set the permissions of /etc/at.allow, run the command:
$ sudo chmod 0640 /etc/at.allow Rationale:If the permissions of the at.allow file are not set to 0640 or more restrictive,
the possibility exists for an unauthorized user to view or edit sensitive information. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
chmod u-xs,g-xws,o-xwrt /etc/at.allow
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91319-4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_at_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/at.allow
ansible.builtin.stat:
path: /etc/at.allow
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91319-4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_at_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xws,o-xwrt on /etc/at.allow
ansible.builtin.file:
path: /etc/at.allow
mode: u-xs,g-xws,o-xwrt
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91319-4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_at_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on /etc/cron.allow file
[ref]ruleIf /etc/cron.allow exists, it must have permissions 0640
or more restrictive.
To properly set the permissions of /etc/cron.allow, run the command:
$ sudo chmod 0640 /etc/cron.allow Rationale:If the permissions of the cron.allow file are not set to 0640 or more restrictive,
the possibility exists for an unauthorized user to view or edit sensitive information. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
chmod u-xs,g-xws,o-xwrt /etc/cron.allow
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91320-2
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/cron.allow
ansible.builtin.stat:
path: /etc/cron.allow
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91320-2
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xws,o-xwrt on /etc/cron.allow
ansible.builtin.file:
path: /etc/cron.allow
mode: u-xs,g-xws,o-xwrt
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91320-2
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Install the cron service
[ref]ruleThe Cron service should be installed. Rationale:The cron service allow periodic job execution, needed for almost all administrative tasks and services (software update, log rotating, etc.). Access to cron service should be restricted to administrative accounts only. Identifiers:
CCE-91379-8 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, 5.1.1, SLES-15-300600015, 2.2.6, 2.2 Remediation script: (show)
[[packages]]
name = "cronie"
version = "*"
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_cronie
class install_cronie {
package { 'cronie':
ensure => 'installed',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
zypper install -y "cronie"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91379-8
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_cron_installed
- name: Ensure cronie is installed
ansible.builtin.package:
name: cronie
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91379-8
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_cron_installed
|
Enable cron Service
[ref]ruleThe crond service is used to execute commands at
preconfigured times. It is required by almost all systems to perform necessary
maintenance tasks, such as notifying root of system activity.
The cron service can be enabled with the following command:
$ sudo systemctl enable cron.service Rationale:Due to its usage for maintenance and security-supporting tasks,
enabling the cron daemon is essential. Identifiers:
CCE-91437-4 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-6(a), PR.IP-1, PR.PT-3, 5.1.1, SLES-15-300600015 Remediation script: (show)
[customizations.services]
enabled = ["cron"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include enable_cron
class enable_cron {
service {'cron':
enable => true,
ensure => 'running',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" unmask 'cron.service'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" start 'cron.service'
fi
"$SYSTEMCTL_EXEC" enable 'cron.service'
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91437-4
- NIST-800-53-CM-6(a)
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_cron_enabled
- name: Enable cron Service - Enable service cron
block:
- name: Gather the package facts
ansible.builtin.package_facts:
manager: auto
- name: Enable cron Service - Enable Service cron
ansible.builtin.systemd:
name: cron
enabled: true
state: started
masked: false
when:
- '"cron" in ansible_facts.packages'
tags:
- CCE-91437-4
- NIST-800-53-CM-6(a)
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_cron_enabled
- special_service_block
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
Verify Group Who Owns cron.d
[ref]rule
To properly set the group owner of /etc/cron.d, run the command:
$ sudo chgrp root /etc/cron.d
Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the
correct group to prevent unauthorized changes. Identifiers:
CCE-91391-3 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.7, SLES-15-300600105, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
find -P /etc/cron.d/ -maxdepth 0 -type d ! -group 0 -exec chgrp --no-dereference "$newgroup" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91391-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_d
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_groupowner_cron_d_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_cron_d_newgroup: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91391-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_d
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/cron.d/
ansible.builtin.file:
path: /etc/cron.d/
follow: false
state: directory
group: '{{ file_groupowner_cron_d_newgroup }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91391-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_d
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns cron.daily
[ref]rule
To properly set the group owner of /etc/cron.daily, run the command:
$ sudo chgrp root /etc/cron.daily
Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the
correct group to prevent unauthorized changes. Identifiers:
CCE-91385-5 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.4, SLES-15-300600060, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
find -P /etc/cron.daily/ -maxdepth 0 -type d ! -group 0 -exec chgrp --no-dereference "$newgroup" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91385-5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_daily
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_groupowner_cron_daily_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_cron_daily_newgroup: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91385-5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_daily
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/cron.daily/
ansible.builtin.file:
path: /etc/cron.daily/
follow: false
state: directory
group: '{{ file_groupowner_cron_daily_newgroup }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91385-5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_daily
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns cron.hourly
[ref]rule
To properly set the group owner of /etc/cron.hourly, run the command:
$ sudo chgrp root /etc/cron.hourly
Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the
correct group to prevent unauthorized changes. Identifiers:
CCE-91382-2 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.3, SLES-15-300600045, SLES-15-600150045, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
find -P /etc/cron.hourly/ -maxdepth 0 -type d ! -group 0 -exec chgrp --no-dereference "$newgroup" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91382-2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_hourly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_groupowner_cron_hourly_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_cron_hourly_newgroup: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91382-2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_hourly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/cron.hourly/
ansible.builtin.file:
path: /etc/cron.hourly/
follow: false
state: directory
group: '{{ file_groupowner_cron_hourly_newgroup }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91382-2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_hourly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns cron.monthly
[ref]rule
To properly set the group owner of /etc/cron.monthly, run the command:
$ sudo chgrp root /etc/cron.monthly
Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the
correct group to prevent unauthorized changes. Identifiers:
CCE-91388-9 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.6, SLES-15-300600090, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
find -P /etc/cron.monthly/ -maxdepth 0 -type d ! -group 0 -exec chgrp --no-dereference "$newgroup" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91388-9
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_monthly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_groupowner_cron_monthly_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_cron_monthly_newgroup: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91388-9
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_monthly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/cron.monthly/
ansible.builtin.file:
path: /etc/cron.monthly/
follow: false
state: directory
group: '{{ file_groupowner_cron_monthly_newgroup }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91388-9
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_monthly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns cron.weekly
[ref]rule
To properly set the group owner of /etc/cron.weekly, run the command:
$ sudo chgrp root /etc/cron.weekly
Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the
correct group to prevent unauthorized changes. Identifiers:
CCE-91386-3 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.5, SLES-15-300600075, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
find -P /etc/cron.weekly/ -maxdepth 0 -type d ! -group 0 -exec chgrp --no-dereference "$newgroup" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91386-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_weekly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_groupowner_cron_weekly_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_cron_weekly_newgroup: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91386-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_weekly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/cron.weekly/
ansible.builtin.file:
path: /etc/cron.weekly/
follow: false
state: directory
group: '{{ file_groupowner_cron_weekly_newgroup }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91386-3
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_cron_weekly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Group Who Owns Crontab
[ref]rule
To properly set the group owner of /etc/crontab, run the command:
$ sudo chgrp root /etc/crontab
Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the
correct group to prevent unauthorized changes. Identifiers:
CCE-91380-6 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.2, SLES-15-300600030, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/crontab" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/crontab
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91380-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_crontab
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_groupowner_crontab_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_crontab_newgroup: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91380-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_crontab
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/crontab
ansible.builtin.stat:
path: /etc/crontab
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91380-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_crontab
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/crontab
ansible.builtin.file:
path: /etc/crontab
follow: false
group: '{{ file_groupowner_crontab_newgroup }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91380-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_crontab
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Owner on cron.d
[ref]rule
To properly set the owner of /etc/cron.d, run the command:
$ sudo chown root /etc/cron.d
Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the
correct user to prevent unauthorized changes. Identifiers:
CCE-91390-5 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.7, SLES-15-300600105, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
find -P /etc/cron.d/ -maxdepth 0 -type d ! -user 0 -exec chown --no-dereference "$newown" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91390-5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_d
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_owner_cron_d_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_cron_d_newown: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91390-5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_d
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on directory /etc/cron.d/
ansible.builtin.file:
path: /etc/cron.d/
follow: false
state: directory
owner: '{{ file_owner_cron_d_newown }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91390-5
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_d
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Owner on cron.hourly
[ref]rule
To properly set the owner of /etc/cron.hourly, run the command:
$ sudo chown root /etc/cron.hourly
Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the
correct user to prevent unauthorized changes. Identifiers:
CCE-91383-0 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.3, SLES-15-300600045, SLES-15-600150045, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
find -P /etc/cron.hourly/ -maxdepth 0 -type d ! -user 0 -exec chown --no-dereference "$newown" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91383-0
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_hourly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_owner_cron_hourly_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_cron_hourly_newown: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91383-0
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_hourly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on directory /etc/cron.hourly/
ansible.builtin.file:
path: /etc/cron.hourly/
follow: false
state: directory
owner: '{{ file_owner_cron_hourly_newown }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91383-0
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_hourly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Owner on cron.monthly
[ref]rule
To properly set the owner of /etc/cron.monthly, run the command:
$ sudo chown root /etc/cron.monthly
Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the
correct user to prevent unauthorized changes. Identifiers:
CCE-91389-7 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.6, SLES-15-300600090, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
find -P /etc/cron.monthly/ -maxdepth 0 -type d ! -user 0 -exec chown --no-dereference "$newown" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91389-7
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_monthly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_owner_cron_monthly_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_cron_monthly_newown: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91389-7
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_monthly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on directory /etc/cron.monthly/
ansible.builtin.file:
path: /etc/cron.monthly/
follow: false
state: directory
owner: '{{ file_owner_cron_monthly_newown }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91389-7
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_monthly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Owner on cron.weekly
[ref]rule
To properly set the owner of /etc/cron.weekly, run the command:
$ sudo chown root /etc/cron.weekly
Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the
correct user to prevent unauthorized changes. Identifiers:
CCE-91387-1 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.5, SLES-15-300600075, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
find -P /etc/cron.weekly/ -maxdepth 0 -type d ! -user 0 -exec chown --no-dereference "$newown" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91387-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_weekly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_owner_cron_weekly_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_cron_weekly_newown: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91387-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_weekly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on directory /etc/cron.weekly/
ansible.builtin.file:
path: /etc/cron.weekly/
follow: false
state: directory
owner: '{{ file_owner_cron_weekly_newown }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91387-1
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_cron_weekly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Owner on crontab
[ref]rule
To properly set the owner of /etc/crontab, run the command:
$ sudo chown root /etc/crontab
Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the
correct user to prevent unauthorized changes. Identifiers:
CCE-91381-4 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.2, SLES-15-300600030, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/crontab" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/crontab
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91381-4
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_crontab
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_owner_crontab_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_crontab_newown: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91381-4
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_crontab
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/crontab
ansible.builtin.stat:
path: /etc/crontab
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91381-4
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_crontab
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/crontab
ansible.builtin.file:
path: /etc/crontab
follow: false
owner: '{{ file_owner_crontab_newown }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91381-4
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_crontab
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on cron.d
[ref]rule
To properly set the permissions of /etc/cron.d, run the command:
$ sudo chmod 0700 /etc/cron.d Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the
correct access rights to prevent unauthorized changes. Identifiers:
CCE-91304-6 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.7, SLES-15-300600105, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
find -H /etc/cron.d/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91304-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_d
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/cron.d/ file(s)
ansible.builtin.command: 'find -P /etc/cron.d/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type
d '
register: files_found
changed_when: false
failed_when: false
check_mode: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91304-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_d
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set permissions for /etc/cron.d/ file(s)
ansible.builtin.file:
path: '{{ item }}'
mode: u-s,g-xwrs,o-xwrt
state: directory
with_items:
- '{{ files_found.stdout_lines }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91304-6
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_d
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on cron.daily
[ref]rule
To properly set the permissions of /etc/cron.daily, run the command:
$ sudo chmod 0700 /etc/cron.daily Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the
correct access rights to prevent unauthorized changes. Identifiers:
CCE-91301-2 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.4, SLES-15-300600060, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
find -H /etc/cron.daily/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91301-2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_daily
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/cron.daily/ file(s)
ansible.builtin.command: 'find -P /etc/cron.daily/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type
d '
register: files_found
changed_when: false
failed_when: false
check_mode: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91301-2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_daily
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set permissions for /etc/cron.daily/ file(s)
ansible.builtin.file:
path: '{{ item }}'
mode: u-s,g-xwrs,o-xwrt
state: directory
with_items:
- '{{ files_found.stdout_lines }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91301-2
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_daily
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on cron.hourly
[ref]rule
To properly set the permissions of /etc/cron.hourly, run the command:
$ sudo chmod 0700 /etc/cron.hourly Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the
correct access rights to prevent unauthorized changes. Identifiers:
CCE-91300-4 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.3, SLES-15-300600045, SLES-15-600150045, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
find -H /etc/cron.hourly/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91300-4
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_hourly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/cron.hourly/ file(s)
ansible.builtin.command: 'find -P /etc/cron.hourly/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type
d '
register: files_found
changed_when: false
failed_when: false
check_mode: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91300-4
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_hourly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set permissions for /etc/cron.hourly/ file(s)
ansible.builtin.file:
path: '{{ item }}'
mode: u-s,g-xwrs,o-xwrt
state: directory
with_items:
- '{{ files_found.stdout_lines }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91300-4
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_hourly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on cron.monthly
[ref]rule
To properly set the permissions of /etc/cron.monthly, run the command:
$ sudo chmod 0700 /etc/cron.monthly Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the
correct access rights to prevent unauthorized changes. Identifiers:
CCE-91303-8 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.6, SLES-15-300600090, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
find -H /etc/cron.monthly/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91303-8
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_monthly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/cron.monthly/ file(s)
ansible.builtin.command: 'find -P /etc/cron.monthly/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type
d '
register: files_found
changed_when: false
failed_when: false
check_mode: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91303-8
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_monthly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set permissions for /etc/cron.monthly/ file(s)
ansible.builtin.file:
path: '{{ item }}'
mode: u-s,g-xwrs,o-xwrt
state: directory
with_items:
- '{{ files_found.stdout_lines }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91303-8
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_monthly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on cron.weekly
[ref]rule
To properly set the permissions of /etc/cron.weekly, run the command:
$ sudo chmod 0700 /etc/cron.weekly Rationale:Service configuration files enable or disable features of their respective services that if configured incorrectly
can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the
correct access rights to prevent unauthorized changes. Identifiers:
CCE-91302-0 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.5, SLES-15-300600075, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
find -H /etc/cron.weekly/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91302-0
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_weekly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/cron.weekly/ file(s)
ansible.builtin.command: 'find -P /etc/cron.weekly/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type
d '
register: files_found
changed_when: false
failed_when: false
check_mode: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91302-0
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_weekly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set permissions for /etc/cron.weekly/ file(s)
ansible.builtin.file:
path: '{{ item }}'
mode: u-s,g-xwrs,o-xwrt
state: directory
with_items:
- '{{ files_found.stdout_lines }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91302-0
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_weekly
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
The Dynamic Host Configuration Protocol (DHCP) allows
systems to request and obtain an IP address and other configuration
parameters from a server.
This guide recommends configuring networking on clients by manually editing
the appropriate files under /etc/sysconfig. Use of DHCP can make client
systems vulnerable to compromise by rogue DHCP servers, and should be avoided
unless necessary. If using DHCP is necessary, however, there are best practices
that should be followed to minimize security risk. |
| contains 3 rules |
Disable DHCP Client
[ref]groupDHCP is the default network configuration method provided by the system
installer, and common on many networks. Nevertheless, manual management
of IP addresses for systems implies a greater degree of management and
accountability for network activity. |
| contains 1 rule |
Uninstall DHCP Client Package
[ref]ruleIf the system does not need to act as a DHCP client,
the dhcp-client package can be uninstalled.
The dhcp-client package can be removed with the following command:
$ sudo zypper remove dhcp-client Rationale:Removing the DHCP client is necessary when the system works
or will work in a static network environment. In this case
the system has/will have a static IP address assigned. Identifiers:
CCE-92511-5 References:
BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.5, SLES-15-300150045 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_dhcp-client
class remove_dhcp-client {
package { 'dhcp-client':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove dhcp-client
# from the system, and may remove any packages
# that depend on dhcp-client. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "dhcp-client"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall DHCP Client Package: Ensure dhcp-client is removed'
ansible.builtin.package:
name: dhcp-client
state: absent
tags:
- CCE-92511-5
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_dhcp_client_removed
|
Disable DHCP Server
[ref]groupThe DHCP server dhcpd is not installed or activated by
default. If the software was installed and activated, but the
system does not need to act as a DHCP server, it should be disabled
and removed. |
| contains 2 rules |
Uninstall DHCP Server Package
[ref]ruleIf the system does not need to act as a DHCP server,
the dhcp package can be uninstalled.
The dhcp-server package can be removed with the following command:
$ sudo zypper remove dhcp-server Rationale:Removing the DHCP server ensures that it cannot be easily or
accidentally reactivated and disrupt network operation. Identifiers:
CCE-85759-9 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.5, R62, SLES-15-300150045, 2.2.4, 2.2 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_dhcp-server
class remove_dhcp-server {
package { 'dhcp-server':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove dhcp-server
# from the system, and may remove any packages
# that depend on dhcp-server. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "dhcp-server"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall DHCP Server Package: Ensure dhcp-server is removed'
ansible.builtin.package:
name: dhcp-server
state: absent
tags:
- CCE-85759-9
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_dhcp_removed
|
Disable DHCP Service
[ref]ruleThe dhcpd service should be disabled on
any system that does not need to act as a DHCP server.
The dhcpd service can be disabled with the following command:
$ sudo systemctl mask --now dhcpd.service Rationale:Unmanaged or unintentionally activated DHCP servers may provide faulty information
to clients, interfering with the operation of a legitimate site
DHCP server if there is one. Identifiers:
CCE-91363-2 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.5, SLES-15-300150045 Remediation script: (show)
[customizations.services]
masked = ["dhcpd"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_dhcpd
class disable_dhcpd {
service {'dhcpd':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'dhcpd.service'
fi
"$SYSTEMCTL_EXEC" disable 'dhcpd.service'
"$SYSTEMCTL_EXEC" mask 'dhcpd.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files dhcpd.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'dhcpd.socket'
fi
"$SYSTEMCTL_EXEC" mask 'dhcpd.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'dhcpd.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91363-2
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_dhcpd_disabled
- name: Disable DHCP Service - Disable service dhcpd
block:
- name: Disable DHCP Service - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable DHCP Service - Ensure dhcpd.service is Masked
ansible.builtin.systemd:
name: dhcpd.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("dhcpd.service", multiline=True)
- name: Unit Socket Exists - dhcpd.socket
ansible.builtin.command: systemctl -q list-unit-files dhcpd.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable DHCP Service - Disable Socket dhcpd
ansible.builtin.systemd:
name: dhcpd.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("dhcpd.socket", multiline=True)
tags:
- CCE-91363-2
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_dhcpd_disabled
- special_service_block
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
DNS Server
[ref]groupMost organizations have an operational need to run at
least one nameserver. However, there are many common attacks
involving DNS server software, and this server software should
be disabled on any system
on which it is not needed. |
| contains 4 rules |
Disable DNS Server
[ref]groupDNS software should be disabled on any systems which does not
need to be a nameserver. Note that the BIND DNS server software is
not installed on SUSE Linux Enterprise 15 by default. The remainder of this section
discusses secure configuration of systems which must be
nameservers. |
| contains 2 rules |
Uninstall bind Package
[ref]ruleThe named service is provided by the bind package.
The bind package can be removed with the following command:
$ sudo zypper remove bind Rationale:If there is no need to make DNS server software available,
removing it provides a safeguard against its activation. Identifiers:
CCE-91285-7 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.9, SLES-15-300150060 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_bind
class remove_bind {
package { 'bind':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove bind
# from the system, and may remove any packages
# that depend on bind. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "bind"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall bind Package: Ensure bind is removed'
ansible.builtin.package:
name: bind
state: absent
tags:
- CCE-91285-7
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_bind_removed
|
Disable named Service
[ref]rule
The named service can be disabled with the following command:
$ sudo systemctl mask --now named.service Rationale:All network services involve some risk of compromise due to
implementation flaws and should be disabled if possible. Identifiers:
CCE-91365-7 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.9, SLES-15-300150060 Remediation script: (show)
[customizations.services]
masked = ["named"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_named
class disable_named {
service {'named':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'named.service'
fi
"$SYSTEMCTL_EXEC" disable 'named.service'
"$SYSTEMCTL_EXEC" mask 'named.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files named.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'named.socket'
fi
"$SYSTEMCTL_EXEC" mask 'named.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'named.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91365-7
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_named_disabled
- name: Disable named Service - Disable service named
block:
- name: Disable named Service - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable named Service - Ensure named.service is Masked
ansible.builtin.systemd:
name: named.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("named.service", multiline=True)
- name: Unit Socket Exists - named.socket
ansible.builtin.command: systemctl -q list-unit-files named.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable named Service - Disable Socket named
ansible.builtin.systemd:
name: named.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("named.socket", multiline=True)
tags:
- CCE-91365-7
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_named_disabled
- special_service_block
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
Uninstall dnsmasq Package
[ref]rulednsmasq is a lightweight tool that provides DNS caching, DNS forwarding and
DHCP (Dynamic Host Configuration Protocol) services.
The dnsmasq package can be removed with the following command:
$ sudo zypper remove dnsmasq Rationale:Unless a system is specifically designated to act as a DNS
caching, DNS forwarding and/or DHCP server, it is recommended that the
package be removed to reduce the potential attack surface. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_dnsmasq
class remove_dnsmasq {
package { 'dnsmasq':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove dnsmasq
# from the system, and may remove any packages
# that depend on dnsmasq. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "dnsmasq"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall dnsmasq Package: Ensure dnsmasq is removed'
ansible.builtin.package:
name: dnsmasq
state: absent
tags:
- CCE-92596-6
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_dnsmasq_removed
|
Disable dnsmasq Service
[ref]rule
The dnsmasq service can be disabled with the following command:
$ sudo systemctl mask --now dnsmasq.service Rationale:Unless a system is specifically designated to act as a DNS
caching, DNS forwarding and/or DHCP server, it is recommended
that the package be removed to reduce the potential attack surface. Remediation script: (show)
[customizations.services]
masked = ["dnsmasq"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_dnsmasq
class disable_dnsmasq {
service {'dnsmasq':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'dnsmasq.service'
fi
"$SYSTEMCTL_EXEC" disable 'dnsmasq.service'
"$SYSTEMCTL_EXEC" mask 'dnsmasq.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files dnsmasq.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'dnsmasq.socket'
fi
"$SYSTEMCTL_EXEC" mask 'dnsmasq.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'dnsmasq.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92602-2
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_dnsmasq_disabled
- name: Disable dnsmasq Service - Disable service dnsmasq
block:
- name: Disable dnsmasq Service - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable dnsmasq Service - Ensure dnsmasq.service is Masked
ansible.builtin.systemd:
name: dnsmasq.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("dnsmasq.service", multiline=True)
- name: Unit Socket Exists - dnsmasq.socket
ansible.builtin.command: systemctl -q list-unit-files dnsmasq.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable dnsmasq Service - Disable Socket dnsmasq
ansible.builtin.systemd:
name: dnsmasq.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("dnsmasq.socket", multiline=True)
tags:
- CCE-92602-2
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_dnsmasq_disabled
- special_service_block
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
FTP Server
[ref]groupFTP is a common method for allowing remote access to
files. Like telnet, the FTP protocol is unencrypted, which means
that passwords and other data transmitted during the session can be
captured and that the session is vulnerable to hijacking.
Therefore, running the FTP server software is not recommended.
However, there are some FTP server configurations which may
be appropriate for some environments, particularly those which
allow only read-only anonymous access as a means of downloading
data available to the public. |
| contains 3 rules |
Disable vsftpd if Possible
[ref]groupTo minimize attack surface, disable vsftpd if at all
possible. |
| contains 2 rules |
Uninstall vsftpd Package
[ref]ruleThe vsftpd package can be removed with the following command: $ sudo zypper remove vsftpd Rationale:Removing the vsftpd package decreases the risk of its
accidental activation. Identifiers:
CCE-85700-3 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), IA-5(1)(c), IA-5(1).1(v), CM-7, CM-7.1(ii), PR.IP-1, PR.PT-3, SRG-OS-000074-GPOS-00042, SRG-OS-000095-GPOS-00049, SRG-OS-000480-GPOS-00227, SLES-15-010030, 2.2.10, SLES-15-300150120, SV-234804r987796_rule Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_vsftpd
class remove_vsftpd {
package { 'vsftpd':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove vsftpd
# from the system, and may remove any packages
# that depend on vsftpd. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "vsftpd"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall vsftpd Package: Ensure vsftpd is removed'
ansible.builtin.package:
name: vsftpd
state: absent
tags:
- CCE-85700-3
- DISA-STIG-SLES-15-010030
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-CM-7.1(ii)
- NIST-800-53-IA-5(1)(c)
- NIST-800-53-IA-5(1).1(v)
- disable_strategy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- package_vsftpd_removed
|
Disable vsftpd Service
[ref]rule
The vsftpd service can be disabled with the following command:
$ sudo systemctl mask --now vsftpd.service Rationale:Running FTP server software provides a network-based avenue
of attack, and should be disabled if not needed.
Furthermore, the FTP protocol is unencrypted and creates
a risk of compromising sensitive information. Identifiers:
CCE-91366-5 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.10, SLES-15-300150120 Remediation script: (show)
[customizations.services]
masked = ["vsftpd"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_vsftpd
class disable_vsftpd {
service {'vsftpd':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'vsftpd.service'
fi
"$SYSTEMCTL_EXEC" disable 'vsftpd.service'
"$SYSTEMCTL_EXEC" mask 'vsftpd.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files vsftpd.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'vsftpd.socket'
fi
"$SYSTEMCTL_EXEC" mask 'vsftpd.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'vsftpd.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91366-5
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_vsftpd_disabled
- name: Disable vsftpd Service - Disable service vsftpd
block:
- name: Disable vsftpd Service - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable vsftpd Service - Ensure vsftpd.service is Masked
ansible.builtin.systemd:
name: vsftpd.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("vsftpd.service", multiline=True)
- name: Unit Socket Exists - vsftpd.socket
ansible.builtin.command: systemctl -q list-unit-files vsftpd.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable vsftpd Service - Disable Socket vsftpd
ansible.builtin.systemd:
name: vsftpd.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("vsftpd.socket", multiline=True)
tags:
- CCE-91366-5
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_vsftpd_disabled
- special_service_block
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
Remove ftp Package
[ref]ruleFTP (File Transfer Protocol) is a traditional and widely used standard tool for
transferring files between a server and clients over a network, especially where no
authentication is necessary (permits anonymous users to connect to a server).
The ftp package can be removed with the following command:
$ sudo zypper remove ftp Rationale:FTP does not protect the confidentiality of data or authentication credentials. It
is recommended SFTP be used if file transfer is required. Unless there is a need
to run the system as a FTP server (for example, to allow anonymous downloads), it is
recommended that the package be removed to reduce the potential attack surface. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_ftp
class remove_ftp {
package { 'ftp':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove ftp
# from the system, and may remove any packages
# that depend on ftp. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "ftp"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Remove ftp Package: Ensure ftp is removed'
ansible.builtin.package:
name: ftp
state: absent
tags:
- CCE-92597-4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_ftp_removed
|
Web Server
[ref]groupThe web server is responsible for providing access to
content via the HTTP protocol. Web servers represent a significant
security risk because:
- The HTTP port is commonly probed by malicious sources
- Web server software is very complex, and includes a long
history of vulnerabilities
- The HTTP protocol is unencrypted and vulnerable to passive
monitoring
The system's default web server software is Apache 2 and is
provided in the RPM package httpd. |
| contains 2 rules |
Disable Apache if Possible
[ref]groupIf Apache was installed and activated, but the system
does not need to act as a web server, then it should be disabled
and removed from the system. |
| contains 2 rules |
Uninstall httpd Package
[ref]ruleThe httpd package can be removed with the following command:
$ sudo zypper remove httpd Rationale:If there is no need to make the web server software available,
removing it provides a safeguard against its activation. Identifiers:
CCE-91286-5 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.11, SLES-15-300150285 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_httpd
class remove_httpd {
package { 'httpd':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove httpd
# from the system, and may remove any packages
# that depend on httpd. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "httpd"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall httpd Package: Ensure httpd is removed'
ansible.builtin.package:
name: httpd
state: absent
tags:
- CCE-91286-5
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- package_httpd_removed
- unknown_severity
|
Disable httpd Service
[ref]rule
The httpd service can be disabled with the following command:
$ sudo systemctl mask --now httpd.service Rationale:Running web server software provides a network-based avenue
of attack, and should be disabled if not needed. Identifiers:
CCE-91367-3 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.11, SLES-15-300150285 Remediation script: (show)
[customizations.services]
masked = ["httpd"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_httpd
class disable_httpd {
service {'httpd':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'httpd.service'
fi
"$SYSTEMCTL_EXEC" disable 'httpd.service'
"$SYSTEMCTL_EXEC" mask 'httpd.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files httpd.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'httpd.socket'
fi
"$SYSTEMCTL_EXEC" mask 'httpd.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'httpd.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91367-3
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- service_httpd_disabled
- unknown_severity
- name: Disable httpd Service - Disable service httpd
block:
- name: Disable httpd Service - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable httpd Service - Ensure httpd.service is Masked
ansible.builtin.systemd:
name: httpd.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("httpd.service", multiline=True)
- name: Unit Socket Exists - httpd.socket
ansible.builtin.command: systemctl -q list-unit-files httpd.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable httpd Service - Disable Socket httpd
ansible.builtin.systemd:
name: httpd.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("httpd.socket", multiline=True)
tags:
- CCE-91367-3
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- service_httpd_disabled
- special_service_block
- unknown_severity
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
IMAP and POP3 Server
[ref]groupDovecot provides IMAP and POP3 services. It is not
installed by default. The project page at
http://www.dovecot.org
contains more detailed information about Dovecot
configuration. |
| contains 3 rules |
Disable Cyrus IMAP
[ref]groupIf the system does not need to operate as an IMAP or
POP3 server, the Cyrus IMAP software should be removed. |
| contains 1 rule |
Uninstall cyrus-imapd Package
[ref]ruleThe cyrus-imapd package can be removed with the following command:
$ sudo zypper remove cyrus-imapd Rationale:If there is no need to make the cyrus-imapd software available,
removing it provides a safeguard against its activation. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_cyrus-imapd
class remove_cyrus-imapd {
package { 'cyrus-imapd':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove cyrus-imapd
# from the system, and may remove any packages
# that depend on cyrus-imapd. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "cyrus-imapd"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall cyrus-imapd Package: Ensure cyrus-imapd is removed'
ansible.builtin.package:
name: cyrus-imapd
state: absent
tags:
- CCE-92595-8
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- package_cyrus-imapd_removed
- unknown_severity
|
Disable Dovecot
[ref]groupIf the system does not need to operate as an IMAP or
POP3 server, the dovecot software should be disabled and removed. |
| contains 2 rules |
Uninstall dovecot Package
[ref]rule
The dovecot package can be removed with the following command:
$ sudo zypper remove dovecot Rationale:If there is no need to make the Dovecot software available,
removing it provides a safeguard against its activation. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_dovecot
class remove_dovecot {
package { 'dovecot':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove dovecot
# from the system, and may remove any packages
# that depend on dovecot. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "dovecot"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall dovecot Package: Ensure dovecot is removed'
ansible.builtin.package:
name: dovecot
state: absent
tags:
- CCE-91369-9
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- package_dovecot_removed
- unknown_severity
|
Disable Dovecot Service
[ref]rule
The dovecot service can be disabled with the following command:
$ sudo systemctl mask --now dovecot.service Rationale:Running an IMAP or POP3 server provides a network-based
avenue of attack, and should be disabled if not needed. Remediation script: (show)
[customizations.services]
masked = ["dovecot"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_dovecot
class disable_dovecot {
service {'dovecot':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'dovecot.service'
fi
"$SYSTEMCTL_EXEC" disable 'dovecot.service'
"$SYSTEMCTL_EXEC" mask 'dovecot.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files dovecot.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'dovecot.socket'
fi
"$SYSTEMCTL_EXEC" mask 'dovecot.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'dovecot.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91368-1
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- service_dovecot_disabled
- unknown_severity
- name: Disable Dovecot Service - Disable service dovecot
block:
- name: Disable Dovecot Service - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable Dovecot Service - Ensure dovecot.service is Masked
ansible.builtin.systemd:
name: dovecot.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("dovecot.service", multiline=True)
- name: Unit Socket Exists - dovecot.socket
ansible.builtin.command: systemctl -q list-unit-files dovecot.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable Dovecot Service - Disable Socket dovecot
ansible.builtin.systemd:
name: dovecot.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("dovecot.socket", multiline=True)
tags:
- CCE-91368-1
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- service_dovecot_disabled
- special_service_block
- unknown_severity
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
LDAP is a popular directory service, that is, a
standardized way of looking up information from a central database.
SUSE Linux Enterprise 15 includes software that enables a system to act as both
an LDAP client and server. |
| contains 3 rules |
Configure OpenLDAP Clients
[ref]groupThis section provides information on which security settings are
important to configure in OpenLDAP clients by manually editing the appropriate
configuration files. SUSE Linux Enterprise 15 provides an automated configuration tool called
authconfig and a graphical wrapper for authconfig called
system-config-authentication. However, these tools do not provide as
much control over configuration as manual editing of configuration files. The
authconfig tools do not allow you to specify locations of SSL certificate
files, which is useful when trying to use SSL cleanly across several protocols.
Installation and configuration of OpenLDAP on SUSE Linux Enterprise 15 is available at Warning:
Before configuring any system to be an
LDAP client, ensure that a working LDAP server is present on the
network. |
| contains 1 rule |
Ensure LDAP client is not installed
[ref]ruleThe Lightweight Directory Access Protocol (LDAP) is a service that provides
a method for looking up information from a central database.
The openldap2-client package can be removed with the following command:
$ sudo zypper remove openldap2-client Rationale:If the system does not need to act as an LDAP client, it is recommended that the software is removed to reduce the potential attack surface. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_openldap2-client
class remove_openldap2-client {
package { 'openldap2-client':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove openldap2-client
# from the system, and may remove any packages
# that depend on openldap2-client. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "openldap2-client"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Ensure LDAP client is not installed: Ensure openldap2-client is removed'
ansible.builtin.package:
name: openldap2-client
state: absent
tags:
- CCE-91310-3
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_openldap-clients_removed
|
Configure OpenLDAP Server
[ref]groupThis section details some security-relevant settings
for an OpenLDAP server. |
| contains 2 rules |
Uninstall openldap-servers Package
[ref]ruleThe openldap2 package is not installed by default on a SUSE Linux Enterprise 15
system. It is needed only by the OpenLDAP server, not by the
clients which use LDAP for authentication. If the system is not
intended for use as an LDAP Server it should be removed. Rationale:Unnecessary packages should not be installed to decrease the attack
surface of the system. While this software is clearly essential on an LDAP
server, it is not necessary on typical desktop or workstation systems. Identifiers:
CCE-91283-2 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.6, SLES-15-300150105 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_openldap2
class remove_openldap2 {
package { 'openldap2':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove openldap2
# from the system, and may remove any packages
# that depend on openldap2. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "openldap2"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall openldap-servers Package: Ensure openldap2 is removed'
ansible.builtin.package:
name: openldap2
state: absent
tags:
- CCE-91283-2
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_openldap-servers_removed
|
Disable LDAP Server (slapd)
[ref]ruleThe Lightweight Directory Access Protocol (LDAP) is a service that
provides a method for looking up information from a central database. Rationale:If the system will not need to act as an LDAP server, it is recommended
that the software be disabled to reduce the potential attack surface. Remediation script: (show)
[customizations.services]
masked = ["slapd"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_slapd
class disable_slapd {
service {'slapd':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'slapd.service'
fi
"$SYSTEMCTL_EXEC" disable 'slapd.service'
"$SYSTEMCTL_EXEC" mask 'slapd.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files slapd.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'slapd.socket'
fi
"$SYSTEMCTL_EXEC" mask 'slapd.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'slapd.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92603-0
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_slapd_disabled
- name: Disable LDAP Server (slapd) - Disable service slapd
block:
- name: Disable LDAP Server (slapd) - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable LDAP Server (slapd) - Ensure slapd.service is Masked
ansible.builtin.systemd:
name: slapd.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("slapd.service", multiline=True)
- name: Unit Socket Exists - slapd.socket
ansible.builtin.command: systemctl -q list-unit-files slapd.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable LDAP Server (slapd) - Disable Socket slapd
ansible.builtin.systemd:
name: slapd.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("slapd.socket", multiline=True)
tags:
- CCE-92603-0
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_slapd_disabled
- special_service_block
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
Mail Server Software
[ref]groupMail servers are used to send and receive email over the network.
Mail is a very common service, and Mail Transfer Agents (MTAs) are obvious
targets of network attack.
Ensure that systems are not running MTAs unnecessarily,
and configure needed MTAs as defensively as possible.
Very few systems at any site should be configured to directly receive email over the
network. Users should instead use mail client programs to retrieve email
from a central server that supports protocols such as IMAP or POP3.
However, it is normal for most systems to be independently capable of sending email,
for instance so that cron jobs can report output to an administrator.
Most MTAs, including Postfix, support a submission-only mode in which mail can be sent from
the local system to a central site MTA (or directly delivered to a local account),
but the system still cannot receive mail directly over a network.
The alternatives program in SUSE Linux Enterprise 15 permits selection of other mail server software
(such as Sendmail), but Postfix is the default and is preferred.
Postfix was coded with security in mind and can also be more effectively contained by
SELinux as its modular design has resulted in separate processes performing specific actions.
More information is available on its website,
http://www.postfix.org. |
| contains 1 rule |
Configure SMTP For Mail Clients
[ref]groupThis section discusses settings for Postfix in a submission-only
e-mail configuration. |
| contains 1 rule |
Disable Postfix Network Listening
[ref]ruleEdit the file /etc/postfix/main.cf to ensure that only the following
inet_interfaces line appears:
inet_interfaces = loopback-only Rationale:This ensures postfix accepts mail messages
(such as cron job reports) from the local system only,
and not from the network, which protects it from network attack. Identifiers:
CCE-91280-8 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.16, R74, SLES-15-300150330, 1.4.2, 1.4 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q postfix; }; then
var_postfix_inet_interfaces='loopback-only'
if [ -e "/etc/postfix/main.cf" ] ; then
LC_ALL=C sed -i "/^\s*inet_interfaces\s\+=\s\+/Id" "/etc/postfix/main.cf"
else
touch "/etc/postfix/main.cf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/postfix/main.cf"
cp "/etc/postfix/main.cf" "/etc/postfix/main.cf.bak"
# Insert at the end of the file
printf '%s\n' "inet_interfaces=$var_postfix_inet_interfaces" >> "/etc/postfix/main.cf"
# Clean up after ourselves.
rm "/etc/postfix/main.cf.bak"
systemctl restart postfix
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91280-8
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- postfix_network_listening_disabled
- restrict_strategy
- name: XCCDF Value var_postfix_inet_interfaces # promote to variable
set_fact:
var_postfix_inet_interfaces: !!str loopback-only
tags:
- always
- name: Gather list of packages
ansible.builtin.package_facts:
manager: auto
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"postfix" in ansible_facts.packages'
tags:
- CCE-91280-8
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- postfix_network_listening_disabled
- restrict_strategy
- name: Make changes to Postfix configuration file
ansible.builtin.lineinfile:
path: /etc/postfix/main.cf
create: false
regexp: (?i)^inet_interfaces\s*=\s.*
line: inet_interfaces = {{ var_postfix_inet_interfaces }}
state: present
insertafter: ^inet_interfaces\s*=\s.*
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"postfix" in ansible_facts.packages'
- '"postfix" in ansible_facts.packages'
tags:
- CCE-91280-8
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- postfix_network_listening_disabled
- restrict_strategy
|
NFS and RPC
[ref]groupThe Network File System is a popular distributed filesystem for
the Unix environment, and is very widely deployed. This section discusses the
circumstances under which it is possible to disable NFS and its dependencies,
and then details steps which should be taken to secure
NFS's configuration. This section is relevant to systems operating as NFS
clients, as well as to those operating as NFS servers. |
| contains 4 rules |
Disable All NFS Services if Possible
[ref]groupIf there is not a reason for the system to operate as either an
NFS client or an NFS server, follow all instructions in this section to disable
subsystems required by NFS. Warning:
The steps in this section will prevent a system
from operating as either an NFS client or an NFS server. Only perform these
steps on systems which do not need NFS at all. |
| contains 2 rules |
Disable Services Used Only by NFS
[ref]groupIf NFS is not needed, disable the NFS client daemons nfslock, rpcgssd, and rpcidmapd.
All of these daemons run with elevated privileges, and many listen for network
connections. If they are not needed, they should be disabled to improve system
security posture. |
| contains 2 rules |
Uninstall rpcbind Package
[ref]ruleThe rpcbind utility maps RPC services to the ports on which they listen.
RPC processes notify rpcbind when they start, registering the ports they
are listening on and the RPC program numbers they expect to serve. The
rpcbind service redirects the client to the proper port number so it can
communicate with the requested service. If the system does not require RPC
(such as for NFS servers) then this service should be disabled.
The rpcbind package can be removed with the following command:
$ sudo zypper remove rpcbind Rationale:If the system does not require rpc based services, it is recommended that
rpcbind be disabled to reduce the attack surface. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_rpcbind
class remove_rpcbind {
package { 'rpcbind':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# CAUTION: This remediation script will remove rpcbind
# from the system, and may remove any packages
# that depend on rpcbind. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "rpcbind"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92467-0
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_rpcbind_removed
- name: 'Uninstall rpcbind Package: Ensure rpcbind is removed'
ansible.builtin.package:
name: rpcbind
state: absent
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92467-0
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_rpcbind_removed
|
Disable rpcbind Service
[ref]ruleThe rpcbind utility maps RPC services to the ports on which they listen.
RPC processes notify rpcbind when they start, registering the ports they
are listening on and the RPC program numbers they expect to serve. The
rpcbind service redirects the client to the proper port number so it can
communicate with the requested service. If the system does not require RPC
(such as for NFS servers) then this service should be disabled.
The rpcbind service can be disabled with the following command:
$ sudo systemctl mask --now rpcbind.service Rationale:If the system does not require rpc based services, it is recommended that
rpcbind be disabled to reduce the attack surface. Remediation script: (show)
[customizations.services]
masked = ["rpcbind"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_rpcbind
class disable_rpcbind {
service {'rpcbind':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'rpcbind.service'
fi
"$SYSTEMCTL_EXEC" disable 'rpcbind.service'
"$SYSTEMCTL_EXEC" mask 'rpcbind.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files rpcbind.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'rpcbind.socket'
fi
"$SYSTEMCTL_EXEC" mask 'rpcbind.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'rpcbind.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91312-9
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- service_rpcbind_disabled
- name: Disable rpcbind Service - Disable service rpcbind
block:
- name: Disable rpcbind Service - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable rpcbind Service - Ensure rpcbind.service is Masked
ansible.builtin.systemd:
name: rpcbind.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("rpcbind.service", multiline=True)
- name: Unit Socket Exists - rpcbind.socket
ansible.builtin.command: systemctl -q list-unit-files rpcbind.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable rpcbind Service - Disable Socket rpcbind
ansible.builtin.systemd:
name: rpcbind.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("rpcbind.socket", multiline=True)
tags:
- CCE-91312-9
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- service_rpcbind_disabled
- special_service_block
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
Configure NFS Clients
[ref]groupThe steps in this section are appropriate for systems which operate as NFS clients. |
| contains 1 rule |
Disable NFS Server Daemons
[ref]groupThere is no need to run the NFS server daemons nfs and
rpcsvcgssd except on a small number of properly secured systems
designated as NFS servers. Ensure that these daemons are turned off on
clients. |
| contains 1 rule |
Disable Network File System (nfs)
[ref]ruleThe Network File System (NFS) service allows remote hosts to mount
and interact with shared filesystems on the local system. If the local system
is not designated as a NFS server then this service should be disabled.
The nfs-server service can be disabled with the following command:
$ sudo systemctl mask --now nfs-server.service Rationale:Unnecessary services should be disabled to decrease the attack surface of the system. Identifiers:
CCE-91364-0 References:
11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), PR.AC-4, PR.AC-6, PR.PT-3, 2.2.7, SLES-15-300150150 Remediation script: (show)
[customizations.services]
masked = ["nfs-server"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_nfs-server
class disable_nfs-server {
service {'nfs-server':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'nfs-server.service'
fi
"$SYSTEMCTL_EXEC" disable 'nfs-server.service'
"$SYSTEMCTL_EXEC" mask 'nfs-server.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files nfs-server.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'nfs-server.socket'
fi
"$SYSTEMCTL_EXEC" mask 'nfs-server.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'nfs-server.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91364-0
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- service_nfs_disabled
- unknown_severity
- name: Disable Network File System (nfs) - Disable service nfs-server
block:
- name: Disable Network File System (nfs) - Collect systemd Services Present in
the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable Network File System (nfs) - Ensure nfs-server.service is Masked
ansible.builtin.systemd:
name: nfs-server.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("nfs-server.service", multiline=True)
- name: Unit Socket Exists - nfs-server.socket
ansible.builtin.command: systemctl -q list-unit-files nfs-server.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable Network File System (nfs) - Disable Socket nfs-server
ansible.builtin.systemd:
name: nfs-server.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("nfs-server.socket", multiline=True)
tags:
- CCE-91364-0
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- service_nfs_disabled
- special_service_block
- unknown_severity
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
Uninstall nfs-utils Package
[ref]ruleThe nfs-utils package can be removed with the following command:
$ sudo zypper remove nfs-utils Rationale:nfs-utils provides a daemon for the kernel NFS server and related tools. This
package also contains the showmount program. showmount queries the mount
daemon on a remote host for information about the Network File System (NFS) server on the
remote host. For example, showmount can display the clients which are mounted on
that host. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_nfs-utils
class remove_nfs-utils {
package { 'nfs-utils':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove nfs-utils
# from the system, and may remove any packages
# that depend on nfs-utils. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "nfs-utils"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall nfs-utils Package: Ensure nfs-utils is removed'
ansible.builtin.package:
name: nfs-utils
state: absent
tags:
- CCE-91284-0
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_nfs-utils_removed
|
Network Time Protocol
[ref]groupThe Network Time Protocol is used to manage the system
clock over a network. Computer clocks are not very accurate, so
time will drift unpredictably on unmanaged systems. Central time
protocols can be used both to ensure that time is consistent among
a network of systems, and that their time is consistent with the
outside world.
If every system on a network reliably reports the same time, then it is much
easier to correlate log messages in case of an attack. In addition, a number of
cryptographic protocols (such as Kerberos) use timestamps to prevent certain
types of attacks. If your network does not have synchronized time, these
protocols may be unreliable or even unusable.
Depending on the specifics of the network, global time accuracy may be just as
important as local synchronization, or not very important at all. If your
network is connected to the Internet, using a public timeserver (or one
provided by your enterprise) provides globally accurate timestamps which may be
essential in investigating or responding to an attack which originated outside
of your network.
A typical network setup involves a small number of internal systems operating
as NTP servers, and the remainder obtaining time information from those
internal servers.
There is a choice between the daemons ntpd and chronyd, which
are available from the repositories in the ntp and chrony
packages respectively.
The default chronyd daemon can work well when external time references
are only intermittently accessible, can perform well even when the network is
congested for longer periods of time, can usually synchronize the clock faster
and with better time accuracy, and quickly adapts to sudden changes in the rate
of the clock, for example, due to changes in the temperature of the crystal
oscillator. Chronyd should be considered for all systems which are
frequently suspended or otherwise intermittently disconnected and reconnected
to a network. Mobile and virtual systems for example.
The ntpd NTP daemon fully supports NTP protocol version 4 (RFC 5905),
including broadcast, multicast, manycast clients and servers, and the orphan
mode. It also supports extra authentication schemes based on public-key
cryptography (RFC 5906). The NTP daemon (ntpd) should be considered
for systems which are normally kept permanently on. Systems which are required
to use broadcast or multicast IP, or to perform authentication of packets with
the Autokey protocol, should consider using ntpd.
Refer to
https://en.wikipedia.org/wiki/Network_Time_Protocol
for more detailed comparison of features of chronyd
and ntpd daemon features respectively, and for further guidance how to
choose between the two NTP daemons.
The upstream manual pages at
https://chrony-project.org/documentation.html for
chronyd and
http://www.ntp.org for ntpd provide additional
information on the capabilities and configuration of each of the NTP daemons. |
| contains 8 rules |
The Chrony package is installed
[ref]ruleSystem time should be synchronized between all systems in an environment. This is
typically done by establishing an authoritative time server or set of servers and having all
systems synchronize their clocks to them.
The chrony package can be installed with the following command:
$ sudo zypper install chrony Rationale:Time synchronization is important to support time sensitive security mechanisms like
Kerberos and also ensures log files have consistent time records across the enterprise,
which aids in forensic investigations. Remediation script: (show)
[[packages]]
name = "chrony"
version = "*"
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_chrony
class install_chrony {
package { 'chrony':
ensure => 'installed',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
zypper install -y "chrony"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91229-5
- PCI-DSS-Req-10.4
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_chrony_installed
- name: Ensure chrony is installed
ansible.builtin.package:
name: chrony
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91229-5
- PCI-DSS-Req-10.4
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_chrony_installed
|
The Chronyd service is enabled
[ref]rulechrony is a daemon which implements the Network Time Protocol (NTP) is designed to
synchronize system clocks across a variety of systems and use a source that is highly
accurate. More information on chrony can be found at
https://chrony-project.org/.
Chrony can be configured to be a client and/or a server.
To enable Chronyd service, you can run:
# systemctl enable chronyd.service
This recommendation only applies if chrony is in use on the system. Rationale:If chrony is in use on the system proper configuration is vital to ensuring time
synchronization is working properly. Remediation script: (show)
[customizations.services]
enabled = ["chronyd"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include enable_chronyd
class enable_chronyd {
service {'chronyd':
enable => true,
ensure => 'running',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q chrony; }; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" unmask 'chronyd.service'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" start 'chronyd.service'
fi
"$SYSTEMCTL_EXEC" enable 'chronyd.service'
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92601-4
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_chronyd_enabled
- name: The Chronyd service is enabled - Enable service chronyd
block:
- name: Gather the package facts
ansible.builtin.package_facts:
manager: auto
- name: The Chronyd service is enabled - Enable Service chronyd
ansible.builtin.systemd:
name: chronyd
enabled: true
state: started
masked: false
when:
- '"chrony" in ansible_facts.packages'
tags:
- CCE-92601-4
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_chronyd_enabled
- special_service_block
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"chrony" in ansible_facts.packages'
|
Enable systemd_timesyncd Service
[ref]rule
The systemd_timesyncd service can be enabled with the following command:
$ sudo systemctl enable systemd_timesyncd.service Rationale:Enabling the systemd_timesyncd service ensures that this host
uses the ntp protocol to fetch time data from a ntp server.
Synchronizing time is essential for authentication
services such as Kerberos, but it is also important for maintaining accurate
logs and auditing possible security breaches.
Additional information on Ubuntu network time protocol is
available at
https://help.ubuntu.com/lts/serverguide/NTP.html.en. Identifiers:
CCE-91296-4 References:
1, 14, 15, 16, 3, 5, 6, APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, CM-6(a), AU-8(1)(a), PR.PT-1, Req-10.4, 2.2.1.2, SLES-15-300450045, 10.6.1, 10.6 Remediation script: (show)
[customizations.services]
enabled = ["systemd-timesyncd"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include enable_systemd-timesyncd
class enable_systemd-timesyncd {
service {'systemd-timesyncd':
enable => true,
ensure => 'running',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { ( ! ( rpm --quiet -q chrony ) && ! ( rpm --quiet -q ntp ) ); }; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" unmask 'systemd-timesyncd.service'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" start 'systemd-timesyncd.service'
fi
"$SYSTEMCTL_EXEC" enable 'systemd-timesyncd.service'
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91296-4
- NIST-800-53-AU-8(1)(a)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.1
- enable_strategy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- service_timesyncd_enabled
- name: Enable systemd_timesyncd Service - Enable service systemd-timesyncd
block:
- name: Gather the package facts
ansible.builtin.package_facts:
manager: auto
- name: Enable systemd_timesyncd Service - Enable Service systemd-timesyncd
ansible.builtin.systemd:
name: systemd-timesyncd
enabled: true
state: started
masked: false
when:
- '"systemd" in ansible_facts.packages'
tags:
- CCE-91296-4
- NIST-800-53-AU-8(1)(a)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.1
- enable_strategy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- service_timesyncd_enabled
- special_service_block
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( not ( "chrony" in ansible_facts.packages ) and not ( "ntp" in ansible_facts.packages
) )
|
Chrony Configure Pool and Server
[ref]ruleChrony is a daemon which implements the Network Time Protocol (NTP). It is designed to
synchronize system clocks across a variety of systems and use a source that is highly
accurate. More information on chrony can be found at
https://chrony-project.org/.
Chrony can be configured to be a client and/or a server.
Add or edit server or pool lines to /etc/chrony.conf as appropriate:
server <remote-server>
Multiple servers may be configured.Rationale:If chrony is in use on the system proper configuration is vital to ensuring time
synchronization is working properly. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q chrony; }; then
var_multiple_time_servers='0.suse.pool.ntp.org,1.suse.pool.ntp.org,2.suse.pool.ntp.org,3.suse.pool.ntp.org'
var_multiple_time_pools='0.suse.pool.ntp.org,1.suse.pool.ntp.org,2.suse.pool.ntp.org,3.suse.pool.ntp.org'
config_file="/etc/chrony.conf"
# Check and configigure servers in /etc/chrony.conf
IFS="," read -a SERVERS <<< $var_multiple_time_servers
for srv in "${SERVERS[@]}"
do
NTP_SRV=$(grep -w $srv $config_file)
if [[ ! "$NTP_SRV" == "server "* ]]
then
time_server="server $srv"
echo $time_server >> "$config_file"
fi
done
# Check and configure pools in /etc/chrony.conf
IFS="," read -a POOLS <<< $var_multiple_time_pools
for srv in "${POOLS[@]}"
do
NTP_POOL=$(grep -w $srv $config_file)
if [[ ! "$NTP_POOL" == "pool "* ]]
then
time_server="pool $srv"
echo $time_server >> "$config_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92526-3
- NIST-800-53-AU-8(1)(a)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.3
- chronyd_configure_pool_and_server
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: XCCDF Value var_multiple_time_servers # promote to variable
set_fact:
var_multiple_time_servers: !!str 0.suse.pool.ntp.org,1.suse.pool.ntp.org,2.suse.pool.ntp.org,3.suse.pool.ntp.org
tags:
- always
- name: XCCDF Value var_multiple_time_pools # promote to variable
set_fact:
var_multiple_time_pools: !!str 0.suse.pool.ntp.org,1.suse.pool.ntp.org,2.suse.pool.ntp.org,3.suse.pool.ntp.org
tags:
- always
- name: Chrony Configure Pool and Server - Add missing / update wrong records for
remote time servers
ansible.builtin.lineinfile:
path: /etc/chrony.conf
regexp: ^\s*\bserver\b\s*\b{{ item }}\b$
state: present
line: server {{ item }}
create: true
with_items:
- '{{ var_multiple_time_servers.split(",") }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"chrony" in ansible_facts.packages'
tags:
- CCE-92526-3
- NIST-800-53-AU-8(1)(a)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.3
- chronyd_configure_pool_and_server
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Chrony Configure Pool and Server - Add missing / update wrong records for
remote time pools
ansible.builtin.lineinfile:
path: /etc/chrony.conf
regexp: ^\s*\bpool\b\s*\b{{ item }}\b$
state: present
line: pool {{ item }}
create: true
with_items:
- '{{ var_multiple_time_pools.split(",") }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"chrony" in ansible_facts.packages'
tags:
- CCE-92526-3
- NIST-800-53-AU-8(1)(a)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.3
- chronyd_configure_pool_and_server
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Configure Time Service Maxpoll Interval
[ref]ruleThe maxpoll should be configured to
16 in /etc/ntp.conf or
/etc/chrony.conf (or /etc/chrony.d/) to continuously poll time servers. To configure
maxpoll in /etc/ntp.conf or /etc/chrony.conf (or /etc/chrony.d/)
add the following after each server, pool or peer entry:
maxpoll 16
to server directives. If using chrony, any pool directives
should be configured too.Rationale:Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate.
Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network.
Organizations should consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints). Identifiers:
CCE-83287-3 References:
1, 14, 15, 16, 3, 5, 6, APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, CM-6(a), AU-8(1)(b), AU-12(1), PR.PT-1, SRG-OS-000355-GPOS-00143, SRG-OS-000356-GPOS-00144, SRG-OS-000359-GPOS-00146, SLES-15-010400, SLES-15-300450090, SV-234849r1038944_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { ( rpm --quiet -q chrony || rpm --quiet -q ntp ); }; then
var_time_service_set_maxpoll='16'
pof="/bin/pidof"
CONFIG_FILES="/etc/ntp.conf"
$pof ntpd || {
CHRONY_D_PATH=/etc/chrony.d/
mapfile -t CONFIG_FILES < <(find ${CHRONY_D_PATH}.* -type f -name '*.conf')
CONFIG_FILES+=(/etc/chrony.conf)
}
# get list of ntp files
for config_file in "${CONFIG_FILES[@]}" ; do
# Set maxpoll values to var_time_service_set_maxpoll
sed -i "s/^\(\(server\|pool\|peer\).*maxpoll\) [0-9,-][0-9]*\(.*\)$/\1 $var_time_service_set_maxpoll \3/" "$config_file"
done
for config_file in "${CONFIG_FILES[@]}" ; do
# Add maxpoll to server, pool or peer entries without maxpoll
grep "^\(server\|pool\|peer\)" "$config_file" | grep -v maxpoll | while read -r line ; do
sed -i "s/$line/& maxpoll $var_time_service_set_maxpoll/" "$config_file"
done
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83287-3
- DISA-STIG-SLES-15-010400
- NIST-800-53-AU-12(1)
- NIST-800-53-AU-8(1)(b)
- NIST-800-53-CM-6(a)
- chronyd_or_ntpd_set_maxpoll
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_time_service_set_maxpoll # promote to variable
set_fact:
var_time_service_set_maxpoll: !!str 16
tags:
- always
- name: Configure Time Service Maxpoll Interval - Check That /etc/ntp.conf Exist
ansible.builtin.stat:
path: /etc/ntp.conf
register: ntp_conf_exist_result
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
tags:
- CCE-83287-3
- DISA-STIG-SLES-15-010400
- NIST-800-53-AU-12(1)
- NIST-800-53-AU-8(1)(b)
- NIST-800-53-CM-6(a)
- chronyd_or_ntpd_set_maxpoll
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure Time Service Maxpoll Interval - Update the maxpoll Values in /etc/ntp.conf
ansible.builtin.replace:
path: /etc/ntp.conf
regexp: ^(server.*maxpoll)[ ]+[0-9]+(.*)$
replace: \1 {{ var_time_service_set_maxpoll }}\2
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
- ntp_conf_exist_result.stat.exists
tags:
- CCE-83287-3
- DISA-STIG-SLES-15-010400
- NIST-800-53-AU-12(1)
- NIST-800-53-AU-8(1)(b)
- NIST-800-53-CM-6(a)
- chronyd_or_ntpd_set_maxpoll
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure Time Service Maxpoll Interval - Set the maxpoll Values in /etc/ntp.conf
ansible.builtin.replace:
path: /etc/ntp.conf
regexp: (^server\s+((?!maxpoll).)*)$
replace: \1 maxpoll {{ var_time_service_set_maxpoll }}\n
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
- ntp_conf_exist_result.stat.exists
tags:
- CCE-83287-3
- DISA-STIG-SLES-15-010400
- NIST-800-53-AU-12(1)
- NIST-800-53-AU-8(1)(b)
- NIST-800-53-CM-6(a)
- chronyd_or_ntpd_set_maxpoll
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure Time Service Maxpoll Interval - Check That /etc/chrony.conf Exist
ansible.builtin.stat:
path: /etc/chrony.conf
register: chrony_conf_exist_result
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
tags:
- CCE-83287-3
- DISA-STIG-SLES-15-010400
- NIST-800-53-AU-12(1)
- NIST-800-53-AU-8(1)(b)
- NIST-800-53-CM-6(a)
- chronyd_or_ntpd_set_maxpoll
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure Time Service Maxpoll Interval - Update the maxpoll Values in /etc/chrony.conf
ansible.builtin.replace:
path: /etc/chrony.conf
regexp: ^((?:server|pool|peer).*maxpoll)[ ]+[0-9]+(.*)$
replace: \1 {{ var_time_service_set_maxpoll }}\2
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
- chrony_conf_exist_result.stat.exists
tags:
- CCE-83287-3
- DISA-STIG-SLES-15-010400
- NIST-800-53-AU-12(1)
- NIST-800-53-AU-8(1)(b)
- NIST-800-53-CM-6(a)
- chronyd_or_ntpd_set_maxpoll
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure Time Service Maxpoll Interval - Set the maxpoll Values in /etc/chrony.conf
ansible.builtin.replace:
path: /etc/chrony.conf
regexp: (^(?:server|pool|peer)\s+((?!maxpoll).)*)$
replace: \1 maxpoll {{ var_time_service_set_maxpoll }}\n
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
- chrony_conf_exist_result.stat.exists
tags:
- CCE-83287-3
- DISA-STIG-SLES-15-010400
- NIST-800-53-AU-12(1)
- NIST-800-53-AU-8(1)(b)
- NIST-800-53-CM-6(a)
- chronyd_or_ntpd_set_maxpoll
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure Time Service Maxpoll Interval - Get Conf Files from /etc/chrony.d/
ansible.builtin.find:
path: /etc/chrony.d/
patterns: '*.conf'
file_type: file
register: chrony_d_conf_files
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
tags:
- CCE-83287-3
- DISA-STIG-SLES-15-010400
- NIST-800-53-AU-12(1)
- NIST-800-53-AU-8(1)(b)
- NIST-800-53-CM-6(a)
- chronyd_or_ntpd_set_maxpoll
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure Time Service Maxpoll Interval - Update the maxpoll Values in /etc/chrony.d/
ansible.builtin.replace:
path: '{{ item.path }}'
regexp: ^((?:server|pool|peer).*maxpoll)[ ]+[0-9,-]+(.*)$
replace: \1 {{ var_time_service_set_maxpoll }}\2
loop: '{{ chrony_d_conf_files.files }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
- chrony_d_conf_files.matched
tags:
- CCE-83287-3
- DISA-STIG-SLES-15-010400
- NIST-800-53-AU-12(1)
- NIST-800-53-AU-8(1)(b)
- NIST-800-53-CM-6(a)
- chronyd_or_ntpd_set_maxpoll
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure Time Service Maxpoll Interval - Set the maxpoll Values in /etc/chrony.d/
ansible.builtin.replace:
path: '{{ item.path }}'
regexp: (^(?:server|pool|peer)\s+((?!maxpoll).)*)$
replace: \1 maxpoll {{ var_time_service_set_maxpoll }}\n
loop: '{{ chrony_d_conf_files.files }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( "chrony" in ansible_facts.packages or "ntp" in ansible_facts.packages )
- chrony_d_conf_files.matched
tags:
- CCE-83287-3
- DISA-STIG-SLES-15-010400
- NIST-800-53-AU-12(1)
- NIST-800-53-AU-8(1)(b)
- NIST-800-53-CM-6(a)
- chronyd_or_ntpd_set_maxpoll
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure that chronyd is running under chrony user account
[ref]rulechrony is a daemon which implements the Network Time Protocol (NTP). It is designed to
synchronize system clocks across a variety of systems and use a source that is highly
accurate. More information on chrony can be found at
https://chrony-project.org/.
Chrony can be configured to be a client and/or a server.
To ensure that chronyd is running under chrony user account,
add or edit the
OPTIONS variable in /etc/sysconfig/chronyd to include -u chrony:
OPTIONS="-u chrony"
This recommendation only applies if chrony is in use on the system.Rationale:If chrony is in use on the system proper configuration is vital to ensuring time synchronization
is working properly. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q chrony; }; then
if grep -q 'OPTIONS=.*' /etc/sysconfig/chronyd; then
# trying to solve cases where the parameter after OPTIONS
#may or may not be enclosed in quotes
sed -i -E -e 's/\s*-u\s*\w+\s*/ /' -e 's/^([\s]*OPTIONS=["]?[^"]*)("?)/\1 -u chrony\2/' /etc/sysconfig/chronyd
else
echo 'OPTIONS="-u chrony"' >> /etc/sysconfig/chronyd
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91360-8
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- chronyd_run_as_chrony_user
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Detect if file /etc/sysconfig/chronyd is not empty or missing
ansible.builtin.find:
path: /etc/sysconfig/
patterns: chronyd
contains: ^([\s]*OPTIONS=["]?[^"]*)("?)
register: chronyd_file
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"chrony" in ansible_facts.packages'
tags:
- CCE-91360-8
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- chronyd_run_as_chrony_user
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Remove any previous configuration of user used to run chronyd process
ansible.builtin.replace:
path: /etc/sysconfig/chronyd
regexp: \s*-u\s*\w+\s*
replace: ' '
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"chrony" in ansible_facts.packages'
- chronyd_file is defined and chronyd_file.matched > 0
tags:
- CCE-91360-8
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- chronyd_run_as_chrony_user
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Correct existing line in /etc/sysconfig/chronyd to run chronyd as chrony user
ansible.builtin.lineinfile:
path: /etc/sysconfig/chronyd
regexp: ^([\s]*OPTIONS=["]?[^"]*)("?)
line: \1 -u chrony\2
state: present
backrefs: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"chrony" in ansible_facts.packages'
- chronyd_file is defined and chronyd_file.matched > 0
tags:
- CCE-91360-8
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- chronyd_run_as_chrony_user
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Insert correct line into /etc/sysconfig/chronyd ensuring chronyd runs as chrony
user
ansible.builtin.lineinfile:
path: /etc/sysconfig/chronyd
line: OPTIONS="-u chrony"
state: present
create: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"chrony" in ansible_facts.packages'
- chronyd_file is defined and chronyd_file.matched == 0
tags:
- CCE-91360-8
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- chronyd_run_as_chrony_user
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Configure Systemd Timesyncd Servers
[ref]rulesystemd-timesyncd is a daemon that has been added for synchronizing the system clock
across the network. The systemd-timesyncd daemon implements:
- Implements an SNTP client
- Runs with minimal privileges
- Saves the current clock to disk every time a new NTP sync has been acquired
- Is hooked up with networkd to only operate when network connectivity is available
Add or edit server or pool lines to /etc/systemd/timesyncd.conf as appropriate:
server <remote-server>
Multiple servers may be configured.Rationale:Configuring systemd-timesyncd ensures time synchronization is working properly. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q systemd; }; then
var_multiple_time_servers='0.suse.pool.ntp.org,1.suse.pool.ntp.org,2.suse.pool.ntp.org,3.suse.pool.ntp.org'
IFS=',' read -r -a time_servers_array <<< "$var_multiple_time_servers"
preferred_ntp_servers_array=("${time_servers_array[@]:0:2}")
preferred_ntp_servers=$( echo "${preferred_ntp_servers_array[@]}"|sed -e 's/\s\+/,/g' )
fallback_ntp_servers_array=("${time_servers_array[@]:2}")
fallback_ntp_servers=$( echo "${fallback_ntp_servers_array[@]}"|sed -e 's/\s\+/,/g' )
IFS=" " mapfile -t current_cfg_arr < <(ls -1 /etc/systemd/timesyncd.d/* /etc/systemd/timesyncd.conf.d/* 2>/dev/null)
config_file="/etc/systemd/timesyncd.d/oscap-remedy.conf"
current_cfg_arr+=( "/etc/systemd/timesyncd.conf" )
# Comment existing NTP FallbackNTP settings
for current_cfg in "${current_cfg_arr[@]}"
do
sed -i 's/^NTP/#&/g' "$current_cfg"
sed -i 's/^FallbackNTP/#&/g' "$current_cfg"
done
# Create /etc/systemd/timesyncd.d if it doesn't exist
if [ ! -d "/etc/systemd/timesyncd.d" ]
then
mkdir /etc/systemd/timesyncd.d
fi
# Set primary fallback NTP servers in drop-in configuration
echo "NTP=$preferred_ntp_servers" >> "$config_file"
echo "FallbackNTP=$fallback_ntp_servers" >> "$config_file"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92538-8
- PCI-DSS-Req-10.4.3
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_timesyncd_configured
- name: XCCDF Value var_multiple_time_servers # promote to variable
set_fact:
var_multiple_time_servers: !!str 0.suse.pool.ntp.org,1.suse.pool.ntp.org,2.suse.pool.ntp.org,3.suse.pool.ntp.org
tags:
- always
- name: Configure Systemd Timesyncd Servers - Set Primary NTP Servers
ansible.builtin.set_fact:
preferred_ntp_servers: '{{ var_multiple_time_servers.split(",") | slice(2)| first
| join(",") }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
tags:
- CCE-92538-8
- PCI-DSS-Req-10.4.3
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_timesyncd_configured
- name: Configure Systemd Timesyncd Servers - Set Fallback NTP Servers
ansible.builtin.set_fact:
fallback_ntp_servers: '{{ var_multiple_time_servers.split(",") | slice(2)| list
| last | join(",") }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
tags:
- CCE-92538-8
- PCI-DSS-Req-10.4.3
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_timesyncd_configured
- name: Configure Systemd Timesyncd Servers - Add missing / update wrong records for
NTP servers
ansible.builtin.lineinfile:
path: /etc/systemd/timesyncd.d/oscap-remedy.conf
regexp: ^\s*NTP\s*=
state: present
line: NTP={{ preferred_ntp_servers }}
create: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
tags:
- CCE-92538-8
- PCI-DSS-Req-10.4.3
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_timesyncd_configured
- name: Configure Systemd Timesyncd Servers - Add missing / update wrong records for
fallback servers
ansible.builtin.lineinfile:
path: /etc/systemd/timesyncd.d/oscap-remedy.conf
regexp: ^\s*FallbackNTP\s*=
state: present
line: FallbackNTP={{ fallback_ntp_servers }}
create: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
tags:
- CCE-92538-8
- PCI-DSS-Req-10.4.3
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_timesyncd_configured
|
Configure Systemd Timesyncd Root Distance Servers
[ref]rulesystemd-timesyncd server configuration should have RootDistanceMaxSec is
listed in accordance with local policy. This setting describes the maximum estimated
time required for a packet to travel to the server connected. Rationale:Configuring systemd-timesyncd RootDistanceMaxSec ensures time synchronization
is using servers that are close enough to the client. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q systemd; }; then
config_file="/usr/lib/systemd/timesyncd.conf.d/oscap-remedy.conf"
IFS=" " mapfile -t current_cfg_arr < <(ls -1 /usr/lib/systemd/timesyncd.conf.d/* 2>/dev/null)
current_cfg_arr+=( "/etc/systemd/timesyncd.conf" )
# Comment existing NTP RootDistanceMax settings
if [ ${#current_cfg_arr[@]} -ne 0 ]; then
for current_cfg in "${current_cfg_arr[@]}"
do
sed -i 's/^RootDistanceMax/#&/g' "$current_cfg"
done
fi
# Set RootDistance in drop-in configuration
echo "RootDistanceMax=1" >> "$config_file"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92514-9
- PCI-DSS-Req-10.4.3
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_timesyncd_root_distance_configured
- name: Configure Systemd Timesyncd Root Distance Servers - Add missing / update wrong
records for root distance
ansible.builtin.lineinfile:
path: /usr/lib/systemd/timesyncd.conf.d/oscap-remedy.conf
regexp: ^\s*RootDistanceMax\s*=
state: present
line: RootDistanceMax=1
create: true
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"systemd" in ansible_facts.packages'
tags:
- CCE-92514-9
- PCI-DSS-Req-10.4.3
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_timesyncd_root_distance_configured
|
Obsolete Services
[ref]groupThis section discusses a number of network-visible
services which have historically caused problems for system
security, and for which disabling or severely limiting the service
has been the best available guidance for some time. As a result of
this, many of these services are not installed as part of SUSE Linux Enterprise 15
by default.
Organizations which are running these services should
switch to more secure equivalents as soon as possible.
If it remains absolutely necessary to run one of
these services for legacy reasons, care should be taken to restrict
the service as much as possible, for instance by configuring host
firewall software such as iptables to restrict access to the
vulnerable service to only those remote hosts which have a known
need to use it. |
| contains 13 rules |
Xinetd
[ref]groupThe xinetd service acts as a dedicated listener for some
network services (mostly, obsolete ones) and can be used to provide access
controls and perform some logging. It has been largely obsoleted by other
features, and it is not installed by default. The older Inetd service
is not even available as part of SUSE Linux Enterprise 15. |
| contains 3 rules |
Uninstall tcpd Package
[ref]ruleThe tcpd package can be removed with the following command:
$ sudo zypper remove tcpd Rationale:Administrators can use TCP wrapper library and daemon for host
control over network services. In these implementations,
xinetd runs tcpd program, which first looks
at the incoming connection as well as the access control lists
in the /etc/hosts.allow and /etc/hosts.deny files.
Removing the xinetd package decreases the risk of the
xinetd service's accidental (or intentional) activation. The
removal of tcpd package will support this protective
measure in addition. Identifiers:
CCE-92476-1 References:
11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, 2.1.1, SLES-15-300150300 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_tcpd
class remove_tcpd {
package { 'tcpd':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# CAUTION: This remediation script will remove tcpd
# from the system, and may remove any packages
# that depend on tcpd. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "tcpd"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92476-1
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_tcp_wrappers_removed
- name: 'Uninstall tcpd Package: Ensure tcpd is removed'
ansible.builtin.package:
name: tcpd
state: absent
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92476-1
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_tcp_wrappers_removed
|
Uninstall xinetd Package
[ref]ruleThe xinetd package can be removed with the following command:
$ sudo zypper remove xinetd Rationale:Removing the xinetd package decreases the risk of the
xinetd service's accidental (or intentional) activation. Identifiers:
CCE-91436-6 References:
11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, 2.1.1, R62, SLES-15-300150300, 1409, 2.2.4, 2.2 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_xinetd
class remove_xinetd {
package { 'xinetd':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# CAUTION: This remediation script will remove xinetd
# from the system, and may remove any packages
# that depend on xinetd. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "xinetd"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91436-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_xinetd_removed
- name: 'Uninstall xinetd Package: Ensure xinetd is removed'
ansible.builtin.package:
name: xinetd
state: absent
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91436-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_xinetd_removed
|
Disable xinetd Service
[ref]rule
The xinetd service can be disabled with the following command:
$ sudo systemctl mask --now xinetd.service Rationale:The xinetd service provides a dedicated listener service for some programs,
which is no longer necessary for commonly-used network services. Disabling
it ensures that these uncommon services are not running, and also prevents
attacks against xinetd itself. Identifiers:
CCE-91438-2 References:
11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, 3.4.7, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, 2.1.1, SLES-15-300150300, 1409 Remediation script: (show)
[customizations.services]
masked = ["xinetd"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_xinetd
class disable_xinetd {
service {'xinetd':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'xinetd.service'
fi
"$SYSTEMCTL_EXEC" disable 'xinetd.service'
"$SYSTEMCTL_EXEC" mask 'xinetd.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files xinetd.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'xinetd.socket'
fi
"$SYSTEMCTL_EXEC" mask 'xinetd.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'xinetd.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91438-2
- NIST-800-171-3.4.7
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_xinetd_disabled
- name: Disable xinetd Service - Disable service xinetd
block:
- name: Disable xinetd Service - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable xinetd Service - Ensure xinetd.service is Masked
ansible.builtin.systemd:
name: xinetd.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("xinetd.service", multiline=True)
- name: Unit Socket Exists - xinetd.socket
ansible.builtin.command: systemctl -q list-unit-files xinetd.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable xinetd Service - Disable Socket xinetd
ansible.builtin.systemd:
name: xinetd.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("xinetd.socket", multiline=True)
tags:
- CCE-91438-2
- NIST-800-171-3.4.7
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_xinetd_disabled
- special_service_block
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
The Network Information Service (NIS), also known as 'Yellow
Pages' (YP), and its successor NIS+ have been made obsolete by
Kerberos, LDAP, and other modern centralized authentication
services. NIS should not be used because it suffers from security
problems inherent in its design, such as inadequate protection of
important authentication information. |
| contains 1 rule |
Remove NIS Client
[ref]ruleThe Network Information Service (NIS), formerly known as Yellow Pages,
is a client-server directory service protocol used to distribute system configuration
files. The NIS client (ypbind) was used to bind a system to an NIS server
and receive the distributed configuration files. Rationale:The NIS service is inherently an insecure system that has been vulnerable
to DOS attacks, buffer overflows and has poor authentication for querying
NIS maps. NIS generally has been replaced by such protocols as Lightweight
Directory Access Protocol (LDAP). It is recommended that the service be
removed. Identifiers:
CCE-91159-4 References:
164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 2.3.1, R62, SLES-15-300300045, 1409, 2.2.4, 2.2 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_ypbind
class remove_ypbind {
package { 'ypbind':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove ypbind
# from the system, and may remove any packages
# that depend on ypbind. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "ypbind"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Remove NIS Client: Ensure ypbind is removed'
ansible.builtin.package:
name: ypbind
state: absent
tags:
- CCE-91159-4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- package_ypbind_removed
- unknown_severity
|
Rlogin, Rsh, and Rexec
[ref]groupThe Berkeley r-commands are legacy services which
allow cleartext remote access and have an insecure trust
model. |
| contains 1 rule |
Remove Rsh Trust Files
[ref]ruleThe files /etc/hosts.equiv and ~/.rhosts (in
each user's home directory) list remote hosts and users that are trusted by the
local system when using the rshd daemon.
To remove these files, run the following command to delete them from any
location:
$ sudo rm /etc/hosts.equiv
$ rm ~/.rhosts Rationale:This action is only meaningful if .rhosts support is permitted
through PAM. Trust files are convenient, but when used in conjunction with
the R-services, they can allow unauthenticated access to a system. Identifiers:
CCE-91431-7 References:
11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, 6.2.12, SLES-15-900300135 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q rsh-server; then
find /root -xdev -type f -name ".rhosts" -exec rm -f {} \;
find /home -maxdepth 2 -xdev -type f -name ".rhosts" -exec rm -f {} \;
rm -f /etc/hosts.equiv
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91431-7
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- no_rsh_trust_files
- restrict_strategy
- name: Detect .rhosts files in users home directories
ansible.builtin.find:
paths:
- /root
- /home
recurse: true
patterns: .rhosts
hidden: true
file_type: file
check_mode: false
register: rhosts_locations
when: '"rsh-server" in ansible_facts.packages'
tags:
- CCE-91431-7
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- no_rsh_trust_files
- restrict_strategy
- name: Remove .rhosts files
ansible.builtin.file:
path: '{{ item }}'
state: absent
with_items: '{{ rhosts_locations.files | map(attribute=''path'') | list }}'
when:
- '"rsh-server" in ansible_facts.packages'
- rhosts_locations is success
tags:
- CCE-91431-7
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- no_rsh_trust_files
- restrict_strategy
- name: Remove /etc/hosts.equiv file
ansible.builtin.file:
path: /etc/hosts.equiv
state: absent
when: '"rsh-server" in ansible_facts.packages'
tags:
- CCE-91431-7
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- no_rsh_trust_files
- restrict_strategy
|
Telnet
[ref]groupThe telnet protocol does not provide confidentiality or integrity
for information transmitted on the network. This includes authentication
information such as passwords. Organizations which use telnet should be
actively working to migrate to a more secure protocol. |
| contains 3 rules |
Uninstall telnet-server Package
[ref]ruleThe telnet-server package can be removed with the following command:
$ sudo zypper remove telnet-server Rationale:It is detrimental for operating systems to provide, or install by default,
functionality exceeding requirements or mission objectives. These
unnecessary capabilities are often overlooked and therefore may remain
insecure. They increase the risk to the platform by providing additional
attack vectors.
The telnet service provides an unencrypted remote access service which does
not provide for the confidentiality and integrity of user passwords or the
remote session. If a privileged user were to login using this service, the
privileged user password could be compromised.
Removing the telnet-server package decreases the risk of the
telnet service's accidental (or intentional) activation. Identifiers:
CCE-83273-3 References:
11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, Req-2.2.2, SRG-OS-000095-GPOS-00049, SLES-15-010180, 2.2.19, R62, SLES-15-300150240, 1409, 2.2.4, 2.2, SV-234818r987796_rule Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_telnet-server
class remove_telnet-server {
package { 'telnet-server':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove telnet-server
# from the system, and may remove any packages
# that depend on telnet-server. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "telnet-server"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall telnet-server Package: Ensure telnet-server is removed'
ansible.builtin.package:
name: telnet-server
state: absent
tags:
- CCE-83273-3
- DISA-STIG-SLES-15-010180
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-2.2.2
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- package_telnet-server_removed
|
Remove telnet Clients
[ref]ruleThe telnet client allows users to start connections to other systems via
the telnet protocol. Rationale:The telnet protocol is insecure and unencrypted. The use
of an unencrypted transmission medium could allow an unauthorized user
to steal credentials. The ssh package provides an
encrypted session and stronger security and is included in SUSE Linux Enterprise 15. Identifiers:
CCE-91434-1 References:
3.1.13, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), A.8.2.3, A.13.1.1, A.13.2.1, A.13.2.3, A.14.1.2, A.14.1.3, 2.3.4, R62, SLES-15-300300060, 1409, 2.2.4, 2.2 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_telnet
class remove_telnet {
package { 'telnet':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove telnet
# from the system, and may remove any packages
# that depend on telnet. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "telnet"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Remove telnet Clients: Ensure telnet is removed'
ansible.builtin.package:
name: telnet
state: absent
tags:
- CCE-91434-1
- NIST-800-171-3.1.13
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_telnet_removed
|
Disable telnet Service
[ref]ruleMake sure that the activation of the telnet service on system boot is disabled.
The telnet socket can be disabled with the following command:
$ sudo systemctl mask --now telnet.socket Warning:
If the system relies on xinetd to manage telnet sessions, ensure the telnet service
is disabled by the following line: disable = yes. Note that the xinetd file for
telnet is not created automatically, therefore it might have different names. Rationale:The telnet protocol uses unencrypted network communication, which means that data from the
login session, including passwords and all other information transmitted during the session,
can be stolen by eavesdroppers on the network. The telnet protocol is also subject to
man-in-the-middle attacks. Identifiers:
CCE-91435-8 References:
1, 11, 12, 14, 15, 16, 3, 5, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10, 3.1.13, 3.4.7, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.18.1.4, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CM-7(a), CM-7(b), CM-6(a), IA-5(1)(c), PR.AC-1, PR.AC-3, PR.AC-6, PR.AC-7, PR.IP-1, PR.PT-3, PR.PT-4, SLES-15-300150240, 1409 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if ( rpm --quiet -q telnet-server && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base ); then
SOCKET_NAME="telnet.socket"
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if "$SYSTEMCTL_EXEC" -q list-unit-files --type socket | grep -q "$SOCKET_NAME"; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop "$SOCKET_NAME"
fi
"$SYSTEMCTL_EXEC" mask "$SOCKET_NAME"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91435-8
- NIST-800-171-3.1.13
- NIST-800-171-3.4.7
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-IA-5(1)(c)
- disable_strategy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- service_telnet_disabled
- name: Disable telnet Service - Collect systemd Socket Units Present in the System
ansible.builtin.command:
cmd: systemctl -q list-unit-files --type socket
register: result_systemd_unit_files
changed_when: false
check_mode: false
when: ( "telnet-server" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
tags:
- CCE-91435-8
- NIST-800-171-3.1.13
- NIST-800-171-3.4.7
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-IA-5(1)(c)
- disable_strategy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- service_telnet_disabled
- name: Disable telnet Service - Ensure telnet.socket is Masked
ansible.builtin.systemd:
name: telnet.socket
state: stopped
enabled: false
masked: true
when:
- ( "telnet-server" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
- result_systemd_unit_files.stdout_lines is search("telnet.socket")
tags:
- CCE-91435-8
- NIST-800-171-3.1.13
- NIST-800-171-3.4.7
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-IA-5(1)(c)
- disable_strategy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- service_telnet_disabled
|
TFTP Server
[ref]groupTFTP is a lightweight version of the FTP protocol which has
traditionally been used to configure networking equipment. However,
TFTP provides little security, and modern versions of networking
operating systems frequently support configuration via SSH or other
more secure protocols. A TFTP server should be run only if no more
secure method of supporting existing equipment can be
found. |
| contains 3 rules |
Uninstall tftp-server Package
[ref]ruleThe tftp-server package can be removed with the following command: $ sudo zypper remove tftp-server Rationale:Removing the tftp-server package decreases the risk of the accidental
(or intentional) activation of tftp services.
If TFTP is required for operational support (such as transmission of router
configurations), its use must be documented with the Information Systems
Security Manager (ISSM), restricted to only authorized personnel, and have
access control rules established. Identifiers:
CCE-91227-9 References:
11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, R62, SLES-15-300150255, 2.2.4, 2.2 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_tftp-server
class remove_tftp-server {
package { 'tftp-server':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove tftp-server
# from the system, and may remove any packages
# that depend on tftp-server. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "tftp-server"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall tftp-server Package: Ensure tftp-server is removed'
ansible.builtin.package:
name: tftp-server
state: absent
tags:
- CCE-91227-9
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- package_tftp-server_removed
|
Remove tftp Daemon
[ref]ruleTrivial File Transfer Protocol (TFTP) is a simple file transfer protocol,
typically used to automatically transfer configuration or boot files between systems.
TFTP does not support authentication and can be easily hacked. The package
tftp is a client program that allows for connections to a tftp server. Rationale:It is recommended that TFTP be removed, unless there is a specific need
for TFTP (such as a boot server). In that case, use extreme caution when configuring
the services. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_tftp
class remove_tftp {
package { 'tftp':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove tftp
# from the system, and may remove any packages
# that depend on tftp. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "tftp"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Remove tftp Daemon: Ensure tftp is removed'
ansible.builtin.package:
name: tftp
state: absent
tags:
- CCE-91158-6
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_tftp_removed
|
Disable tftp Service
[ref]ruleThe tftp service should be disabled.
The tftp service can be disabled with the following command:
$ sudo systemctl mask --now tftp.service Rationale:Disabling the tftp service ensures the system is not acting
as a TFTP server, which does not provide encryption or authentication. Identifiers:
CCE-92606-3 References:
11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, 2.1.9, SLES-15-300150255 Remediation script: (show)
[customizations.services]
masked = ["tftp"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_tftp
class disable_tftp {
service {'tftp':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'tftp.service'
fi
"$SYSTEMCTL_EXEC" disable 'tftp.service'
"$SYSTEMCTL_EXEC" mask 'tftp.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files tftp.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'tftp.socket'
fi
"$SYSTEMCTL_EXEC" mask 'tftp.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'tftp.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92606-3
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- service_tftp_disabled
- name: Disable tftp Service - Disable service tftp
block:
- name: Disable tftp Service - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable tftp Service - Ensure tftp.service is Masked
ansible.builtin.systemd:
name: tftp.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("tftp.service", multiline=True)
- name: Unit Socket Exists - tftp.socket
ansible.builtin.command: systemctl -q list-unit-files tftp.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable tftp Service - Disable Socket tftp
ansible.builtin.systemd:
name: tftp.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("tftp.socket", multiline=True)
tags:
- CCE-92606-3
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- service_tftp_disabled
- special_service_block
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
Uninstall rsync Package
[ref]ruleThe rsyncd service can be used to synchronize files between systems over network links.
The rsync package can be removed with the following command:
$ sudo zypper remove rsync Rationale:The rsyncd service presents a security risk as it uses unencrypted protocols for
communication. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_rsync
class remove_rsync {
package { 'rsync':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove rsync
# from the system, and may remove any packages
# that depend on rsync. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "rsync"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall rsync Package: Ensure rsync is removed'
ansible.builtin.package:
name: rsync
state: absent
tags:
- CCE-92468-8
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_rsync_removed
|
Ensure rsyncd service is disabled
[ref]rule
The rsyncd service can be disabled with the following command:
$ sudo systemctl mask --now rsyncd.service Rationale:The rsyncd service presents a security risk as it uses unencrypted protocols for
communication. Remediation script: (show)
[customizations.services]
masked = ["rsyncd"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_rsyncd
class disable_rsyncd {
service {'rsyncd':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'rsyncd.service'
fi
"$SYSTEMCTL_EXEC" disable 'rsyncd.service'
"$SYSTEMCTL_EXEC" mask 'rsyncd.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files rsyncd.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'rsyncd.socket'
fi
"$SYSTEMCTL_EXEC" mask 'rsyncd.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'rsyncd.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91305-3
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_rsyncd_disabled
- name: Ensure rsyncd service is disabled - Disable service rsyncd
block:
- name: Ensure rsyncd service is disabled - Collect systemd Services Present in
the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Ensure rsyncd service is disabled - Ensure rsyncd.service is Masked
ansible.builtin.systemd:
name: rsyncd.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("rsyncd.service", multiline=True)
- name: Unit Socket Exists - rsyncd.socket
ansible.builtin.command: systemctl -q list-unit-files rsyncd.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Ensure rsyncd service is disabled - Disable Socket rsyncd
ansible.builtin.systemd:
name: rsyncd.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("rsyncd.socket", multiline=True)
tags:
- CCE-91305-3
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_rsyncd_disabled
- special_service_block
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
Print Support
[ref]groupThe Common Unix Printing System (CUPS) service provides both local
and network printing support. A system running the CUPS service can accept
print jobs from other systems, process them, and send them to the appropriate
printer. It also provides an interface for remote administration through a web
browser. The CUPS service is installed and activated by default. The project
homepage and more detailed documentation are available at
http://www.cups.org.
|
| contains 2 rules |
Uninstall CUPS Package
[ref]ruleThe cups package can be removed with the following command:
$ sudo zypper remove cups Rationale:If the system does not need to print jobs or accept print jobs from other systems, it is
recommended that CUPS be removed to reduce the potential attack surface. Identifiers:
CCE-92466-2 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.4, SLES-15-300150180 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_cups
class remove_cups {
package { 'cups':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove cups
# from the system, and may remove any packages
# that depend on cups. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "cups"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall CUPS Package: Ensure cups is removed'
ansible.builtin.package:
name: cups
state: absent
tags:
- CCE-92466-2
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- package_cups_removed
- unknown_severity
|
Disable the CUPS Service
[ref]rule
The cups service can be disabled with the following command:
$ sudo systemctl mask --now cups.service Rationale:Turn off unneeded services to reduce attack surface. Identifiers:
CCE-91322-8 References:
11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.4, SLES-15-300150180 Remediation script: (show)
[customizations.services]
masked = ["cups"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_cups
class disable_cups {
service {'cups':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'cups.service'
fi
"$SYSTEMCTL_EXEC" disable 'cups.service'
"$SYSTEMCTL_EXEC" mask 'cups.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files cups.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'cups.socket'
fi
"$SYSTEMCTL_EXEC" mask 'cups.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'cups.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91322-8
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- service_cups_disabled
- unknown_severity
- name: Disable the CUPS Service - Disable service cups
block:
- name: Disable the CUPS Service - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable the CUPS Service - Ensure cups.service is Masked
ansible.builtin.systemd:
name: cups.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("cups.service", multiline=True)
- name: Unit Socket Exists - cups.socket
ansible.builtin.command: systemctl -q list-unit-files cups.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable the CUPS Service - Disable Socket cups
ansible.builtin.systemd:
name: cups.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("cups.socket", multiline=True)
tags:
- CCE-91322-8
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- service_cups_disabled
- special_service_block
- unknown_severity
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
Proxy Server
[ref]groupA proxy server is a very desirable target for a
potential adversary because much (or all) sensitive data for a
given infrastructure may flow through it. Therefore, if one is
required, the system acting as a proxy server should be dedicated
to that purpose alone and be stored in a physically secure
location. The system's default proxy server software is Squid, and
provided in an RPM package of the same name. |
| contains 2 rules |
Disable Squid if Possible
[ref]groupIf Squid was installed and activated, but the system
does not need to act as a proxy server, then it should be disabled
and removed. |
| contains 2 rules |
Uninstall squid Package
[ref]ruleThe squid package can be removed with the following command: $ sudo zypper remove squid Rationale:If there is no need to make the proxy server software available,
removing it provides a safeguard against its activation. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_squid
class remove_squid {
package { 'squid':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove squid
# from the system, and may remove any packages
# that depend on squid. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "squid"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall squid Package: Ensure squid is removed'
ansible.builtin.package:
name: squid
state: absent
tags:
- CCE-91372-3
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- package_squid_removed
- unknown_severity
|
Disable Squid
[ref]rule
The squid service can be disabled with the following command:
$ sudo systemctl mask --now squid.service Rationale:Running proxy server software provides a network-based avenue
of attack, and should be removed if not needed. Remediation script: (show)
[customizations.services]
masked = ["squid"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_squid
class disable_squid {
service {'squid':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if ( rpm --quiet -q squid && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base ); then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'squid.service'
fi
"$SYSTEMCTL_EXEC" disable 'squid.service'
"$SYSTEMCTL_EXEC" mask 'squid.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files squid.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'squid.socket'
fi
"$SYSTEMCTL_EXEC" mask 'squid.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'squid.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91371-5
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- service_squid_disabled
- unknown_severity
- name: Disable Squid - Disable service squid
block:
- name: Disable Squid - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable Squid - Ensure squid.service is Masked
ansible.builtin.systemd:
name: squid.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("squid.service", multiline=True)
- name: Unit Socket Exists - squid.socket
ansible.builtin.command: systemctl -q list-unit-files squid.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable Squid - Disable Socket squid
ansible.builtin.systemd:
name: squid.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("squid.socket", multiline=True)
tags:
- CCE-91371-5
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- service_squid_disabled
- special_service_block
- unknown_severity
when: ( "squid" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
|
Samba(SMB) Microsoft Windows File Sharing Server
[ref]groupWhen properly configured, the Samba service allows
Linux systems to provide file and print sharing to Microsoft
Windows systems. There are two software packages that provide
Samba support. The first, samba-client, provides a series of
command line tools that enable a client system to access Samba
shares. The second, simply labeled samba, provides the Samba
service. It is this second package that allows a Linux system to
act as an Active Directory server, a domain controller, or as a
domain member. Only the samba-client package is installed by
default. |
| contains 2 rules |
Disable Samba if Possible
[ref]groupEven after the Samba server package has been installed, it
will remain disabled. Do not enable this service unless it is
absolutely necessary to provide Microsoft Windows file and print
sharing functionality. |
| contains 2 rules |
Uninstall Samba Package
[ref]ruleThe samba package can be removed with the following command: $ sudo zypper remove samba Rationale:If there is no need to make the Samba software available,
removing it provides a safeguard against its activation. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_samba
class remove_samba {
package { 'samba':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove samba
# from the system, and may remove any packages
# that depend on samba. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "samba"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall Samba Package: Ensure samba is removed'
ansible.builtin.package:
name: samba
state: absent
tags:
- CCE-91287-3
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- package_samba_removed
- unknown_severity
|
Disable Samba
[ref]rule
The smb service can be disabled with the following command:
$ sudo systemctl mask --now smb.service Rationale:Running a Samba server provides a network-based avenue of attack, and
should be disabled if not needed. Remediation script: (show)
[customizations.services]
masked = ["smb"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_smb
class disable_smb {
service {'smb':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'smb.service'
fi
"$SYSTEMCTL_EXEC" disable 'smb.service'
"$SYSTEMCTL_EXEC" mask 'smb.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files smb.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'smb.socket'
fi
"$SYSTEMCTL_EXEC" mask 'smb.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'smb.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91370-7
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- service_smb_disabled
- name: Disable Samba - Disable service smb
block:
- name: Disable Samba - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable Samba - Ensure smb.service is Masked
ansible.builtin.systemd:
name: smb.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("smb.service", multiline=True)
- name: Unit Socket Exists - smb.socket
ansible.builtin.command: systemctl -q list-unit-files smb.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable Samba - Disable Socket smb
ansible.builtin.systemd:
name: smb.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("smb.socket", multiline=True)
tags:
- CCE-91370-7
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- service_smb_disabled
- special_service_block
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
|
SNMP Server
[ref]groupThe Simple Network Management Protocol allows
administrators to monitor the state of network devices, including
computers. Older versions of SNMP were well-known for weak
security, such as plaintext transmission of the community string
(used for authentication) and usage of easily-guessable
choices for the community string. |
| contains 2 rules |
Disable SNMP Server if Possible
[ref]groupThe system includes an SNMP daemon that allows for its remote
monitoring, though it not installed by default. If it was installed and
activated but is not needed, the software should be disabled and removed. |
| contains 2 rules |
Uninstall net-snmp Package
[ref]rule
The net-snmp package provides the snmpd service.
The net-snmp package can be removed with the following command:
$ sudo zypper remove net-snmp Rationale:If there is no need to run SNMP server software,
removing the package provides a safeguard against its
activation. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_net-snmp
class remove_net-snmp {
package { 'net-snmp':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove net-snmp
# from the system, and may remove any packages
# that depend on net-snmp. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "net-snmp"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall net-snmp Package: Ensure net-snmp is removed'
ansible.builtin.package:
name: net-snmp
state: absent
tags:
- CCE-91288-1
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- package_net-snmp_removed
- unknown_severity
|
Disable snmpd Service
[ref]rule
The snmpd service can be disabled with the following command:
$ sudo systemctl mask --now snmpd.service Rationale:Running SNMP software provides a network-based avenue of attack, and
should be disabled if not needed. Remediation script: (show)
[customizations.services]
masked = ["snmpd"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_snmpd
class disable_snmpd {
service {'snmpd':
enable => false,
ensure => 'stopped',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if ( rpm --quiet -q net-snmp && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base ); then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'snmpd.service'
fi
"$SYSTEMCTL_EXEC" disable 'snmpd.service'
"$SYSTEMCTL_EXEC" mask 'snmpd.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files snmpd.socket; then
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" stop 'snmpd.socket'
fi
"$SYSTEMCTL_EXEC" mask 'snmpd.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'snmpd.service' || true
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91373-1
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- service_snmpd_disabled
- name: Disable snmpd Service - Disable service snmpd
block:
- name: Disable snmpd Service - Collect systemd Services Present in the System
ansible.builtin.command: systemctl -q list-unit-files --type service
register: service_exists
changed_when: false
failed_when: service_exists.rc not in [0, 1]
check_mode: false
- name: Disable snmpd Service - Ensure snmpd.service is Masked
ansible.builtin.systemd:
name: snmpd.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("snmpd.service", multiline=True)
- name: Unit Socket Exists - snmpd.socket
ansible.builtin.command: systemctl -q list-unit-files snmpd.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable snmpd Service - Disable Socket snmpd
ansible.builtin.systemd:
name: snmpd.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("snmpd.socket", multiline=True)
tags:
- CCE-91373-1
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- service_snmpd_disabled
- special_service_block
when: ( "net-snmp" in ansible_facts.packages and ("kernel-default" in ansible_facts.packages
or "kernel-default-base" in ansible_facts.packages) )
|
SSH Server
[ref]groupThe SSH protocol is recommended for remote login and
remote file transfer. SSH provides confidentiality and integrity
for data exchanged between two systems, as well as server
authentication, through the use of public key cryptography. The
implementation included with the system is called OpenSSH, and more
detailed documentation is available from its website,
https://www.openssh.com.
Its server program is called sshd and provided by the RPM package
openssh-server. |
| contains 30 rules |
Configure OpenSSH Server if Necessary
[ref]groupIf the system needs to act as an SSH server, then
certain changes should be made to the OpenSSH daemon configuration
file /etc/ssh/sshd_config. The following recommendations can be
applied to this file. See the sshd_config(5) man page for more
detailed information. |
| contains 26 rules |
Disable Host-Based Authentication
[ref]ruleSSH's cryptographic host-based authentication is
more secure than .rhosts authentication. However, it is
not recommended that hosts unilaterally trust one another, even
within an organization.
The default SSH configuration disables host-based authentication. The appropriate
configuration is used if no value is set for HostbasedAuthentication.
To explicitly disable host-based authentication, add or correct the
following line in
/etc/ssh/sshd_config:
HostbasedAuthentication no Rationale:SSH trust relationships mean a compromise on one host
can allow an attacker to move trivially to other hosts. Identifiers:
CCE-91439-0 References:
11, 12, 14, 15, 16, 18, 3, 5, 9, 5.5.6, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.1.12, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-3, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.AC-4, PR.AC-6, PR.IP-1, PR.PT-3, FIA_UAU.1, SRG-OS-000480-GPOS-00229, 5.2.9, SLES-15-600150180, 0421, 0422, 0484, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, 8.3.1, 8.3 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*HostbasedAuthentication\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "HostbasedAuthentication no" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91439-0
- CJIS-5.5.6
- NIST-800-171-3.1.12
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-3
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.1
- disable_host_auth
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable Host-Based Authentication
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*HostbasedAuthentication\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*HostbasedAuthentication\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*HostbasedAuthentication\s+
line: HostbasedAuthentication no
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91439-0
- CJIS-5.5.6
- NIST-800-171-3.1.12
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-3
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSSv4-8.3
- PCI-DSSv4-8.3.1
- disable_host_auth
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Allow Only SSH Protocol 2
[ref]ruleOnly SSH protocol version 2 connections should be
permitted. The default setting in
/etc/ssh/sshd_config is correct, and can be
verified by ensuring that the following
line appears:
Protocol 2 Warning:
As of openssh-server version 7.4 and above, the only protocol
supported is version 2, and line Protocol 2 in
/etc/ssh/sshd_config is not necessary. Rationale:SSH protocol version 1 is an insecure implementation of the SSH protocol and
has many well-known vulnerability exploits. Exploits of the SSH daemon could provide
immediate root access to the system. Identifiers:
CCE-91440-8 References:
1, 12, 15, 16, 5, 8, 5.5.6, APO13.01, DSS01.04, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.13, 3.5.4, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.6, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.13.1.1, A.13.2.1, A.14.1.3, A.18.1.4, A.6.2.1, A.6.2.2, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1, CM-6(a), AC-17(a), AC-17(2), IA-5(1)(c), SC-13, MA-4(6), PR.AC-1, PR.AC-3, PR.AC-6, PR.AC-7, PR.PT-4, SRG-OS-000074-GPOS-00042, SRG-OS-000480-GPOS-00227, SLES-15-600150405, 1483 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*Protocol\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "Protocol 2" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91440-8
- CJIS-5.5.6
- NIST-800-171-3.1.13
- NIST-800-171-3.5.4
- NIST-800-53-AC-17(2)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(c)
- NIST-800-53-MA-4(6)
- NIST-800-53-SC-13
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
- sshd_allow_only_protocol2
- name: Allow Only SSH Protocol 2
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*Protocol\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*Protocol\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*Protocol\s+
line: Protocol 2
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91440-8
- CJIS-5.5.6
- NIST-800-171-3.1.13
- NIST-800-171-3.5.4
- NIST-800-53-AC-17(2)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(c)
- NIST-800-53-MA-4(6)
- NIST-800-53-SC-13
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
- sshd_allow_only_protocol2
|
Disable SSH Access via Empty Passwords
[ref]ruleDisallow SSH login with empty passwords.
The default SSH configuration disables logins with empty passwords. The appropriate
configuration is used if no value is set for PermitEmptyPasswords.
To explicitly disallow SSH login from accounts with empty passwords,
add or correct the following line in
/etc/ssh/sshd_config:
PermitEmptyPasswords no
Any accounts with empty passwords should be disabled immediately, and PAM configuration
should prevent users from being able to assign themselves empty passwords.Rationale:Configuring this setting for the SSH daemon provides additional assurance
that remote login via SSH will require a password, even in the event of
misconfiguration elsewhere. Identifiers:
CCE-85667-4 References:
11, 12, 13, 14, 15, 16, 18, 3, 5, 9, 5.5.6, APO01.06, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, 3.1.1, 3.1.5, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(b), CM-6.1(iv), PR.AC-4, PR.AC-6, PR.DS-5, PR.IP-1, PR.PT-3, FIA_UAU.1, Req-2.2.4, SRG-OS-000106-GPOS-00053, SRG-OS-000480-GPOS-00229, SRG-OS-000480-GPOS-00227, SLES-15-040440, 5.2.11, SLES-15-600150285, 1546, 2.2.6, 2.2, SV-235032r991591_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*PermitEmptyPasswords\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "PermitEmptyPasswords no" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85667-4
- CJIS-5.5.6
- DISA-STIG-SLES-15-040440
- NIST-800-171-3.1.1
- NIST-800-171-3.1.5
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSS-Req-2.2.4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
- sshd_disable_empty_passwords
- name: Disable SSH Access via Empty Passwords
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*PermitEmptyPasswords\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*PermitEmptyPasswords\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*PermitEmptyPasswords\s+
line: PermitEmptyPasswords no
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85667-4
- CJIS-5.5.6
- DISA-STIG-SLES-15-040440
- NIST-800-171-3.1.1
- NIST-800-171-3.1.5
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSS-Req-2.2.4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- high_severity
- low_complexity
- low_disruption
- no_reboot_needed
- restrict_strategy
- sshd_disable_empty_passwords
|
Disable GSSAPI Authentication
[ref]ruleUnless needed, SSH should not permit extraneous or unnecessary
authentication mechanisms like GSSAPI.
The default SSH configuration disallows authentications based on GSSAPI. The appropriate
configuration is used if no value is set for GSSAPIAuthentication.
To explicitly disable GSSAPI authentication, add or correct the following line in
/etc/ssh/sshd_config:
GSSAPIAuthentication no Rationale:GSSAPI authentication is used to provide additional authentication mechanisms to
applications. Allowing GSSAPI authentication through SSH exposes the system's
GSSAPI to remote hosts, increasing the attack surface of the system. Identifiers:
CCE-91441-6 References:
11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.12, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, CM-7(a), CM-7(b), CM-6(a), AC-17(a), PR.IP-1, FTP_ITC_EXT.1, FCS_SSH_EXT.1.2, SRG-OS-000364-GPOS-00151, SRG-OS-000480-GPOS-00227, SLES-15-600150165, 0418, 1055, 1402 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*GSSAPIAuthentication\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "GSSAPIAuthentication no" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91441-6
- NIST-800-171-3.1.12
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_gssapi_auth
- name: Disable GSSAPI Authentication
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*GSSAPIAuthentication\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*GSSAPIAuthentication\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*GSSAPIAuthentication\s+
line: GSSAPIAuthentication no
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91441-6
- NIST-800-171-3.1.12
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_gssapi_auth
|
Disable Kerberos Authentication
[ref]ruleUnless needed, SSH should not permit extraneous or unnecessary
authentication mechanisms like Kerberos.
The default SSH configuration disallows authentication validation through Kerberos.
The appropriate configuration is used if no value is set for KerberosAuthentication.
To explicitly disable Kerberos authentication, add or correct the following line in
/etc/ssh/sshd_config:
KerberosAuthentication no Rationale:Kerberos authentication for SSH is often implemented using GSSAPI. If Kerberos
is enabled through SSH, the SSH daemon provides a means of access to the
system's Kerberos implementation.
Configuring these settings for the SSH daemon provides additional assurance that remote logon via SSH will not use unused methods of authentication, even in the event of misconfiguration elsewhere. Identifiers:
CCE-91442-4 References:
11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.12, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.IP-1, FTP_ITC_EXT.1, FCS_SSH_EXT.1.2, SRG-OS-000364-GPOS-00151, SRG-OS-000480-GPOS-00227, SLES-15-600150435, 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*KerberosAuthentication\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "KerberosAuthentication no" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91442-4
- NIST-800-171-3.1.12
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_kerb_auth
- name: Disable Kerberos Authentication
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*KerberosAuthentication\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*KerberosAuthentication\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*KerberosAuthentication\s+
line: KerberosAuthentication no
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91442-4
- NIST-800-171-3.1.12
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_kerb_auth
|
Disable SSH Support for .rhosts Files
[ref]ruleSSH can emulate the behavior of the obsolete rsh
command in allowing users to enable insecure access to their
accounts via .rhosts files.
The default SSH configuration disables support for .rhosts. The appropriate
configuration is used if no value is set for IgnoreRhosts.
To explicitly disable support for .rhosts files, add or correct the following line in
/etc/ssh/sshd_config:
IgnoreRhosts yes Rationale:SSH trust relationships mean a compromise on one host
can allow an attacker to move trivially to other hosts. Identifiers:
CCE-91307-9 References:
11, 12, 14, 15, 16, 18, 3, 5, 9, 5.5.6, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.1.12, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.AC-4, PR.AC-6, PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, 5.2.8, SLES-15-600150195, 1546, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*IgnoreRhosts\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "IgnoreRhosts yes" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91307-9
- CJIS-5.5.6
- NIST-800-171-3.1.12
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_rhosts
- name: Disable SSH Support for .rhosts Files
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*IgnoreRhosts\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*IgnoreRhosts\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*IgnoreRhosts\s+
line: IgnoreRhosts yes
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91307-9
- CJIS-5.5.6
- NIST-800-171-3.1.12
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_rhosts
|
Disable SSH Root Login
[ref]ruleThe root user should never be allowed to login to a
system directly over a network.
To disable root login via SSH, add or correct the following line in
/etc/ssh/sshd_config:
PermitRootLogin no Rationale:Even though the communications channel may be encrypted, an additional layer of
security is gained by extending the policy of not logging directly on as root.
In addition, logging in with a user-specific account provides individual
accountability of actions performed on the system and also helps to minimize
direct attack attempts on root's password. Identifiers:
CCE-85557-7 References:
1, 11, 12, 13, 14, 15, 16, 18, 3, 5, 5.5.6, APO01.06, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.06, DSS06.10, 3.1.1, 3.1.5, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-6(2), AC-17(a), IA-2, IA-2(5), CM-7(a), CM-7(b), CM-6(a), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, PR.PT-3, FAU_GEN.1, Req-2.2.4, SRG-OS-000109-GPOS-00056, SRG-OS-000480-GPOS-00227, SRG-APP-000148-CTR-000335, SRG-APP-000190-CTR-000500, SLES-15-020040, 5.2.10, R33, SLES-15-600150300, 1546, 2.2.6, 2.2, SV-234870r1009618_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*PermitRootLogin\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "PermitRootLogin no" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85557-7
- CJIS-5.5.6
- DISA-STIG-SLES-15-020040
- NIST-800-171-3.1.1
- NIST-800-171-3.1.5
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(2)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-IA-2
- NIST-800-53-IA-2(5)
- PCI-DSS-Req-2.2.4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_root_login
- name: Disable SSH Root Login
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*PermitRootLogin\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*PermitRootLogin\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*PermitRootLogin\s+
line: PermitRootLogin no
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85557-7
- CJIS-5.5.6
- DISA-STIG-SLES-15-020040
- NIST-800-171-3.1.1
- NIST-800-171-3.1.5
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(2)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-IA-2
- NIST-800-53-IA-2(5)
- PCI-DSS-Req-2.2.4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_root_login
|
Disable SSH TCP Forwarding
[ref]ruleThe AllowTcpForwarding parameter specifies whether TCP forwarding is permitted.
To disable TCP forwarding, add or correct the following line in
/etc/ssh/sshd_config:
AllowTcpForwarding no Rationale:Leaving port forwarding enabled can expose the organization to security risks and back-doors. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*AllowTcpForwarding\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "AllowTcpForwarding no" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91334-3
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_tcp_forwarding
- name: Disable SSH TCP Forwarding
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*AllowTcpForwarding\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*AllowTcpForwarding\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*AllowTcpForwarding\s+
line: AllowTcpForwarding no
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91334-3
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_tcp_forwarding
|
Disable SSH Support for User Known Hosts
[ref]ruleSSH can allow system users to connect to systems if a cache of the remote
systems public keys is available. This should be disabled.
To ensure this behavior is disabled, add or correct the following line in
/etc/ssh/sshd_config:
IgnoreUserKnownHosts yes Rationale:Configuring this setting for the SSH daemon provides additional
assurance that remote login via SSH will require a password, even
in the event of misconfiguration elsewhere. Identifiers:
CCE-85642-7 References:
11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.12, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.IP-1, SRG-OS-000480-GPOS-00227, SLES-15-040230, SLES-15-600150345, 1546, SV-235007r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*IgnoreUserKnownHosts\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "IgnoreUserKnownHosts yes" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85642-7
- DISA-STIG-SLES-15-040230
- NIST-800-171-3.1.12
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_user_known_hosts
- name: Disable SSH Support for User Known Hosts
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*IgnoreUserKnownHosts\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*IgnoreUserKnownHosts\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*IgnoreUserKnownHosts\s+
line: IgnoreUserKnownHosts yes
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85642-7
- DISA-STIG-SLES-15-040230
- NIST-800-171-3.1.12
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_user_known_hosts
|
Disable X11 Forwarding
[ref]ruleThe X11Forwarding parameter provides the ability to tunnel X11 traffic
through the connection to enable remote graphic connections.
SSH has the capability to encrypt remote X11 connections when SSH's
X11Forwarding option is enabled.
The default SSH configuration disables X11Forwarding. The appropriate
configuration is used if no value is set for X11Forwarding.
To explicitly disable X11 Forwarding, add or correct the following line in
/etc/ssh/sshd_config:
X11Forwarding no Rationale:Disable X11 forwarding unless there is an operational requirement to use X11
applications directly. There is a small risk that the remote X11 servers of
users who are logged in via SSH with X11 forwarding could be compromised by
other users on the X11 server. Note that even if X11 forwarding is disabled,
users can always install their own forwarders. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*X11Forwarding\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "X11Forwarding no" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85707-8
- DISA-STIG-SLES-15-040290
- NIST-800-53-CM-6.1(iv)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_x11_forwarding
- name: Disable X11 Forwarding
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*X11Forwarding\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*X11Forwarding\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*X11Forwarding\s+
line: X11Forwarding no
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85707-8
- DISA-STIG-SLES-15-040290
- NIST-800-53-CM-6.1(iv)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_x11_forwarding
|
Do Not Allow SSH Environment Options
[ref]ruleEnsure that users are not able to override environment variables of the SSH daemon.
The default SSH configuration disables environment processing. The appropriate
configuration is used if no value is set for PermitUserEnvironment.
To explicitly disable Environment options, add or correct the following
/etc/ssh/sshd_config:
PermitUserEnvironment no Rationale:SSH environment options potentially allow users to bypass
access restriction in some configurations. Identifiers:
CCE-85666-6 References:
11, 3, 9, 5.5.6, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.12, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, CM-6(b), CM-6.1(iv), PR.IP-1, Req-2.2.4, SRG-OS-000480-GPOS-00229, SLES-15-040440, 5.2.12, SLES-15-600150315, 1546, 2.2.6, 2.2, SV-235032r991591_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*PermitUserEnvironment\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "PermitUserEnvironment no" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85666-6
- CJIS-5.5.6
- DISA-STIG-SLES-15-040440
- NIST-800-171-3.1.12
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSS-Req-2.2.4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_do_not_permit_user_env
- name: Do Not Allow SSH Environment Options
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*PermitUserEnvironment\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*PermitUserEnvironment\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*PermitUserEnvironment\s+
line: PermitUserEnvironment no
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85666-6
- CJIS-5.5.6
- DISA-STIG-SLES-15-040440
- NIST-800-171-3.1.12
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- PCI-DSS-Req-2.2.4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_do_not_permit_user_env
|
Enable PAM
[ref]ruleUsePAM Enables the Pluggable Authentication Module interface. If set to “yes” this will
enable PAM authentication using ChallengeResponseAuthentication and
PasswordAuthentication in addition to PAM account and session module processing for all
authentication types.
To enable PAM authentication, add or correct the following line in
/etc/ssh/sshd_config:
UsePAM yes Rationale:When UsePAM is set to yes, PAM runs through account and session types properly. This is
important if you want to restrict access to services based off of IP, time or other factors of
the account. Additionally, you can make sure users inherit certain environment variables
on login or disallow access to the server. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*UsePAM\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "UsePAM yes" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91333-5
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_enable_pam
- name: Enable PAM
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*UsePAM\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*UsePAM\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*UsePAM\s+
line: UsePAM yes
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91333-5
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_enable_pam
|
Enable Use of Strict Mode Checking
[ref]ruleSSHs StrictModes option checks file and ownership permissions in
the user's home directory .ssh folder before accepting login. If world-
writable permissions are found, logon is rejected.
The default SSH configuration has StrictModes enabled. The appropriate
configuration is used if no value is set for StrictModes.
To explicitly enable StrictModes in SSH, add or correct the following line in
/etc/ssh/sshd_config:
StrictModes yes Rationale:If other users have access to modify user-specific SSH configuration files, they
may be able to log into the system as another user. Identifiers:
CCE-85645-0 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.1.12, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-6, AC-17(a), CM-6(a), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, SLES-15-040260, SLES-15-600150375, 1409, SV-235010r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*StrictModes\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "StrictModes yes" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85645-0
- DISA-STIG-SLES-15-040260
- NIST-800-171-3.1.12
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6
- NIST-800-53-CM-6(a)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_enable_strictmodes
- name: Enable Use of Strict Mode Checking
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*StrictModes\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*StrictModes\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*StrictModes\s+
line: StrictModes yes
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85645-0
- DISA-STIG-SLES-15-040260
- NIST-800-171-3.1.12
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6
- NIST-800-53-CM-6(a)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_enable_strictmodes
|
Enable SSH Warning Banner
[ref]ruleTo enable the warning banner and ensure it is consistent
across the system, add or correct the following line in
/etc/ssh/sshd_config:
Banner /etc/issue
Another section contains information on how to create an
appropriate system-wide warning banner.Rationale:The warning message reinforces policy awareness during the logon process and
facilitates possible legal action against attackers. Alternatively, systems
whose ownership should not be obvious should ensure usage of a banner that does
not provide easy attribution. Identifiers:
CCE-83263-4 References:
1, 12, 15, 16, 5.5.6, DSS05.04, DSS05.10, DSS06.10, 3.1.9, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, AC-8(a), AC-8(c), AC-17(a), CM-6(a), PR.AC-7, FTA_TAB.1, Req-2.2.4, SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088, SLES-15-010040, 5.2.18, SLES-15-600150120, 0484, SV-234805r958390_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*Banner\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "Banner /etc/issue" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83263-4
- CJIS-5.5.6
- DISA-STIG-SLES-15-010040
- NIST-800-171-3.1.9
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(c)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-2.2.4
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_enable_warning_banner
- name: Enable SSH Warning Banner
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*Banner\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*Banner\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*Banner\s+
line: Banner /etc/issue
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83263-4
- CJIS-5.5.6
- DISA-STIG-SLES-15-010040
- NIST-800-171-3.1.9
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-8(a)
- NIST-800-53-AC-8(c)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-2.2.4
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_enable_warning_banner
|
Limit Users' SSH Access
[ref]ruleBy default, the SSH configuration allows any user with an account
to access the system. There are several options available to limit
which users and group can access the system via SSH. It is
recommended that at least one of the following options be leveraged:
- AllowUsers variable gives the system administrator the option of
allowing specific users to ssh into the system. The list consists of
space separated user names. Numeric user IDs are not recognized with
this variable. If a system administrator wants to restrict user
access further by specifically allowing a user's access only from a
particular host, the entry can be specified in the form of user@host.
- AllowGroups variable gives the system administrator the option of
allowing specific groups of users to ssh into the system. The list
consists of space separated group names. Numeric group IDs are not
recognized with this variable.
- DenyUsers variable gives the system administrator the option of
denying specific users to ssh into the system. The list consists of
space separated user names. Numeric user IDs are not recognized with
this variable. If a system administrator wants to restrict user
access further by specifically denying a user's access from a
particular host, the entry can be specified in the form of user@host.
- DenyGroups variable gives the system administrator the option of
denying specific groups of users to ssh into the system. The list
consists of space separated group names. Numeric group IDs are not
recognized with this variable. Warning:
Automated remediation is not available for this configuration check
because each system has unique user names and group names. Rationale:Specifying which accounts are allowed SSH access into the system reduces the
possibility of unauthorized access to the system. Identifiers:
CCE-91343-4 References:
11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.1.12, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-3, CM-6(a), PR.AC-4, PR.AC-6, PR.PT-3, Req-2.2.4, 5.2.4, SLES-15-600150105, 2.2.6, 2.2 |
Enable SSH Print Last Log
[ref]ruleEnsure that SSH will display the date and time of the last successful account logon.
The default SSH configuration enables print of the date and time of the last login.
The appropriate configuration is used if no value is set for PrintLastLog.
To explicitly enable LastLog in SSH, add or correct the following line in
/etc/ssh/sshd_config:
PrintLastLog yes Rationale:Providing users feedback on when account accesses last occurred facilitates user
recognition and reporting of unauthorized account use. Identifiers:
CCE-85563-5 References:
1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, AC-9, AC-9(1), PR.AC-7, SRG-OS-000480-GPOS-00227, SLES-15-020120, SLES-15-600150390, 0582, 0846, SV-234881r991589_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*PrintLastLog\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "PrintLastLog yes" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85563-5
- DISA-STIG-SLES-15-020120
- NIST-800-53-AC-9
- NIST-800-53-AC-9(1)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_print_last_log
- name: Enable SSH Print Last Log
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*PrintLastLog\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*PrintLastLog\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*PrintLastLog\s+
line: PrintLastLog yes
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85563-5
- DISA-STIG-SLES-15-020120
- NIST-800-53-AC-9
- NIST-800-53-AC-9(1)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_print_last_log
|
Ensure SSH LoginGraceTime is configured
[ref]ruleThe LoginGraceTime parameter to the SSH server specifies the time allowed for successful authentication to
the SSH server. The longer the Grace period is the more open unauthenticated connections
can exist. Like other session controls in this session the Grace Period should be limited to
appropriate limits to ensure the service is available for needed access. Rationale:Setting the LoginGraceTime parameter to a low number will minimize the risk of successful
brute force attacks to the SSH server. It will also limit the number of concurrent
unauthenticated connections. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_sshd_set_login_grace_time='60'
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*LoginGraceTime\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "LoginGraceTime $var_sshd_set_login_grace_time" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91397-0
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_set_login_grace_time
- name: XCCDF Value var_sshd_set_login_grace_time # promote to variable
set_fact:
var_sshd_set_login_grace_time: !!str 60
tags:
- always
- name: Ensure SSH LoginGraceTime is configured
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*LoginGraceTime\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*LoginGraceTime\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*LoginGraceTime\s+
line: LoginGraceTime {{ var_sshd_set_login_grace_time }}
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91397-0
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_set_login_grace_time
|
Set SSH Daemon LogLevel to VERBOSE
[ref]ruleThe VERBOSE parameter configures the SSH daemon to record login and logout activity.
To specify the log level in
SSH, add or correct the following line in
/etc/ssh/sshd_config:
LogLevel VERBOSE Rationale:SSH provides several logging levels with varying amounts of verbosity. DEBUG is specifically
not recommended other than strictly for debugging SSH communications since it provides
so much data that it is difficult to identify important security information. INFO or
VERBOSE level is the basic level that only records login activity of SSH users. In many
situations, such as Incident Response, it is important to determine when a particular user was active
on a system. The logout record can eliminate those users who disconnected, which helps narrow the
field. Identifiers:
CCE-83270-9 References:
CIP-007-3 R7.1, AC-17(a), AC-17(1), CM-6(a), Req-2.2.4, SRG-OS-000032-GPOS-00013, SLES-15-010150, 5.2.5, SLES-15-600150225, 2.2.6, 2.2, SV-234815r958406_rule Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*LogLevel\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "LogLevel VERBOSE" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83270-9
- DISA-STIG-SLES-15-010150
- NIST-800-53-AC-17(1)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-2.2.4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_set_loglevel_verbose
- name: Set SSH Daemon LogLevel to VERBOSE
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*LogLevel\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*LogLevel\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*LogLevel\s+
line: LogLevel VERBOSE
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-83270-9
- DISA-STIG-SLES-15-010150
- NIST-800-53-AC-17(1)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-2.2.4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_set_loglevel_verbose
|
Set SSH authentication attempt limit
[ref]ruleThe MaxAuthTries parameter specifies the maximum number of authentication attempts
permitted per connection. Once the number of failures reaches half this value, additional failures are logged.
to set MaxAUthTries edit /etc/ssh/sshd_config as follows:
MaxAuthTries 4 Rationale:Setting the MaxAuthTries parameter to a low number will minimize the risk of successful
brute force attacks to the SSH server. Identifiers:
CCE-91332-7 References:
5.2.7, SLES-15-600150240, 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
sshd_max_auth_tries_value='4'
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*MaxAuthTries\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "MaxAuthTries $sshd_max_auth_tries_value" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91332-7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_set_max_auth_tries
- name: XCCDF Value sshd_max_auth_tries_value # promote to variable
set_fact:
sshd_max_auth_tries_value: !!str 4
tags:
- always
- name: Set SSH authentication attempt limit
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MaxAuthTries\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MaxAuthTries\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MaxAuthTries\s+
line: MaxAuthTries {{ sshd_max_auth_tries_value }}
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91332-7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_set_max_auth_tries
|
Set SSH MaxSessions limit
[ref]ruleThe MaxSessions parameter specifies the maximum number of open sessions permitted
from a given connection. To set MaxSessions edit
/etc/ssh/sshd_config as follows: MaxSessions 10 Rationale:To protect a system from denial of service due to a large number of concurrent
sessions, use the rate limiting function of MaxSessions to protect availability
of sshd logins and prevent overwhelming the daemon. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_sshd_max_sessions='10'
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*MaxSessions\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "MaxSessions $var_sshd_max_sessions" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91309-5
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_set_max_sessions
- name: XCCDF Value var_sshd_max_sessions # promote to variable
set_fact:
var_sshd_max_sessions: !!str 10
tags:
- always
- name: Set SSH MaxSessions limit
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MaxSessions\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MaxSessions\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MaxSessions\s+
line: MaxSessions {{ var_sshd_max_sessions }}
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91309-5
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_set_max_sessions
|
Ensure SSH MaxStartups is configured
[ref]ruleThe MaxStartups parameter specifies the maximum number of concurrent unauthenticated
connections to the SSH daemon. Additional connections will be dropped until authentication
succeeds or the LoginGraceTime expires for a connection. To configure MaxStartups, you should
add or edit the following line in the /etc/ssh/sshd_config file:
MaxStartups 10:30:60 Rationale:To protect a system from denial of service due to a large number of pending authentication
connection attempts, use the rate limiting function of MaxStartups to protect availability of
sshd logins and prevent overwhelming the daemon. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_sshd_set_maxstartups='10:30:60'
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*MaxStartups\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "MaxStartups $var_sshd_set_maxstartups" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91308-7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_set_maxstartups
- name: XCCDF Value var_sshd_set_maxstartups # promote to variable
set_fact:
var_sshd_set_maxstartups: !!str 10:30:60
tags:
- always
- name: Ensure SSH MaxStartups is configured
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MaxStartups\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MaxStartups\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MaxStartups\s+
line: MaxStartups {{ var_sshd_set_maxstartups }}
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91308-7
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_set_maxstartups
|
Use Only FIPS 140-2 Validated Ciphers
[ref]ruleLimit the ciphers to those algorithms which are FIPS-approved.
Counter (CTR) mode is also preferred over cipher-block chaining (CBC) mode.
The following line in /etc/ssh/sshd_config
demonstrates use of FIPS-approved ciphers:
Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc
The man page sshd_config(5) contains a list of supported ciphers.
The rule is parametrized to use the following ciphers: chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr.Warning:
The system needs to be rebooted for these changes to take effect. Warning:
System Crypto Modules must be provided by a vendor that undergoes
FIPS-140 certifications.
FIPS-140 is applicable to all Federal agencies that use
cryptographic-based security systems to protect sensitive information
in computer and telecommunication systems (including voice systems) as
defined in Section 5131 of the Information Technology Management Reform
Act of 1996, Public Law 104-106. This standard shall be used in
designing and implementing cryptographic modules that Federal
departments and agencies operate or are operated for them under
contract. See https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.140-2.pdf
To meet this, the system has to have cryptographic software provided by
a vendor that has undergone this certification. This means providing
documentation, test results, design information, and independent third
party review by an accredited lab. While open source software is
capable of meeting this, it does not meet FIPS-140 unless the vendor
submits to this process. Rationale:Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore
cannot be relied upon to provide confidentiality or integrity, and system data may be compromised.
Operating systems utilizing encryption are required to use FIPS-compliant mechanisms for authenticating to
cryptographic modules.
FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules
utilize authentication that meets industry and government requirements. For government systems, this allows
Security Levels 1, 2, 3, or 4 for use on SUSE Linux Enterprise 15. Identifiers:
CCE-91337-6 References:
1, 11, 12, 14, 15, 16, 18, 3, 5, 6, 8, 9, 5.5.6, APO11.04, APO13.01, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10, MEA02.01, 3.1.13, 3.13.11, 3.13.8, 164.308(b)(1), 164.308(b)(2), 164.312(e)(1), 164.312(e)(2)(i), 164.312(e)(2)(ii), 164.314(b)(2)(i), 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.5.1, A.12.6.2, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.18.1.4, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CM-6(a), AC-17(a), AC-17(2), SC-13, MA-4(6), IA-5(1)(c), SC-12(2), SC-12(3), PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-1, PR.PT-1, PR.PT-3, PR.PT-4, SRG-OS-000033-GPOS-00014, SRG-OS-000120-GPOS-00061, SRG-OS-000125-GPOS-00065, SRG-OS-000250-GPOS-00093, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174, SLES-15-010160, 5.2.13, SLES-15-600150060, 2.2.7, 2.2, SV-234816r958408_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
sshd_approved_ciphers='chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr'
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^Ciphers")
# shellcheck disable=SC2059
printf -v formatted_output "%s %s" "$stripped_key" "$sshd_approved_ciphers"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^Ciphers\\>" "/etc/ssh/sshd_config"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^Ciphers\\>.*/$escaped_formatted_output/gi" "/etc/ssh/sshd_config"
else
if [[ -s "/etc/ssh/sshd_config" ]] && [[ -n "$(tail -c 1 -- "/etc/ssh/sshd_config" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/ssh/sshd_config"
fi
cce="CCE-91337-6"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/ssh/sshd_config" >> "/etc/ssh/sshd_config"
printf '%s\n' "$formatted_output" >> "/etc/ssh/sshd_config"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91337-6
- CJIS-5.5.6
- DISA-STIG-SLES-15-010160
- NIST-800-171-3.1.13
- NIST-800-171-3.13.11
- NIST-800-171-3.13.8
- NIST-800-53-AC-17(2)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(c)
- NIST-800-53-MA-4(6)
- NIST-800-53-SC-12(2)
- NIST-800-53-SC-12(3)
- NIST-800-53-SC-13
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.7
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_use_approved_ciphers
- name: XCCDF Value sshd_approved_ciphers # promote to variable
set_fact:
sshd_approved_ciphers: !!str chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
tags:
- always
- name: Use Only FIPS 140-2 Validated Ciphers
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*Ciphers\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*Ciphers\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*Ciphers\s+
line: Ciphers {{ sshd_approved_ciphers }}
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91337-6
- CJIS-5.5.6
- DISA-STIG-SLES-15-010160
- NIST-800-171-3.1.13
- NIST-800-171-3.13.11
- NIST-800-171-3.13.8
- NIST-800-53-AC-17(2)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(c)
- NIST-800-53-MA-4(6)
- NIST-800-53-SC-12(2)
- NIST-800-53-SC-12(3)
- NIST-800-53-SC-13
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.7
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_use_approved_ciphers
|
Use Only FIPS 140-2 Validated MACs
[ref]ruleLimit the MACs to those hash algorithms which are FIPS-approved.
The following line in /etc/ssh/sshd_config
demonstrates use of FIPS-approved MACs:
MACs hmac-sha2-512,hmac-sha2-256
The man page sshd_config(5) contains a list of supported MACs.
The rule is parametrized to use the following MACs: hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512,hmac-sha2-256.Warning:
The system needs to be rebooted for these changes to take effect. Warning:
System Crypto Modules must be provided by a vendor that undergoes
FIPS-140 certifications.
FIPS-140 is applicable to all Federal agencies that use
cryptographic-based security systems to protect sensitive information
in computer and telecommunication systems (including voice systems) as
defined in Section 5131 of the Information Technology Management Reform
Act of 1996, Public Law 104-106. This standard shall be used in
designing and implementing cryptographic modules that Federal
departments and agencies operate or are operated for them under
contract. See https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.140-2.pdf
To meet this, the system has to have cryptographic software provided by
a vendor that has undergone this certification. This means providing
documentation, test results, design information, and independent third
party review by an accredited lab. While open source software is
capable of meeting this, it does not meet FIPS-140 unless the vendor
submits to this process. Rationale:FIPS-approved cryptographic hash functions are required to be used.
The only SSHv2 hash algorithms meeting this requirement is SHA2. Identifiers:
CCE-91338-4 References:
1, 12, 13, 15, 16, 5, 8, APO01.06, APO13.01, DSS01.04, DSS05.02, DSS05.03, DSS05.04, DSS05.07, DSS06.02, DSS06.03, 3.1.13, 3.13.11, 3.13.8, 164.308(b)(1), 164.308(b)(2), 164.312(e)(1), 164.312(e)(2)(i), 164.312(e)(2)(ii), 164.314(b)(2)(i), 4.3.3.5.1, 4.3.3.6.6, SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.6, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.11.2.6, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CM-6(a), AC-17(a), AC-17(2), SC-13, MA-4(6), SC-12(2), SC-12(3), PR.AC-1, PR.AC-3, PR.DS-5, PR.PT-4, SRG-OS-000125-GPOS-00065, SRG-OS-000250-GPOS-00093, SRG-OS-000394-GPOS-00174, SLES-15-010270, 5.2.14, SLES-15-600150090, 2.2.7, 2.2, SV-234826r958510_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
sshd_approved_macs='hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512,hmac-sha2-256'
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^MACs")
# shellcheck disable=SC2059
printf -v formatted_output "%s %s" "$stripped_key" "$sshd_approved_macs"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^MACs\\>" "/etc/ssh/sshd_config"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^MACs\\>.*/$escaped_formatted_output/gi" "/etc/ssh/sshd_config"
else
if [[ -s "/etc/ssh/sshd_config" ]] && [[ -n "$(tail -c 1 -- "/etc/ssh/sshd_config" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/ssh/sshd_config"
fi
cce="CCE-91338-4"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "/etc/ssh/sshd_config" >> "/etc/ssh/sshd_config"
printf '%s\n' "$formatted_output" >> "/etc/ssh/sshd_config"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91338-4
- DISA-STIG-SLES-15-010270
- NIST-800-171-3.1.13
- NIST-800-171-3.13.11
- NIST-800-171-3.13.8
- NIST-800-53-AC-17(2)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-MA-4(6)
- NIST-800-53-SC-12(2)
- NIST-800-53-SC-12(3)
- NIST-800-53-SC-13
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.7
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_use_approved_macs
- name: XCCDF Value sshd_approved_macs # promote to variable
set_fact:
sshd_approved_macs: !!str hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512,hmac-sha2-256
tags:
- always
- name: Use Only FIPS 140-2 Validated MACs
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MACs\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MACs\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MACs\s+
line: MACs {{ sshd_approved_macs }}
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91338-4
- DISA-STIG-SLES-15-010270
- NIST-800-171-3.1.13
- NIST-800-171-3.13.11
- NIST-800-171-3.13.8
- NIST-800-53-AC-17(2)
- NIST-800-53-AC-17(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-MA-4(6)
- NIST-800-53-SC-12(2)
- NIST-800-53-SC-12(3)
- NIST-800-53-SC-13
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.7
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_use_approved_macs
|
Use Only Strong Ciphers
[ref]ruleLimit the ciphers to strong algorithms.
Counter (CTR) mode is also preferred over cipher-block chaining (CBC) mode.
The following line in /etc/ssh/sshd_config
demonstrates use of those ciphers:
Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
The man page sshd_config(5) contains a list of supported ciphers.Rationale:Based on research conducted at various institutions, it was determined that the symmetric
portion of the SSH Transport Protocol (as described in RFC 4253) has security weaknesses
that allowed recovery of up to 32 bits of plaintext from a block of ciphertext that was
encrypted with the Cipher Block Chaining (CBD) method. From that research, new Counter
mode algorithms (as described in RFC4344) were designed that are not vulnerable to these
types of attacks and these algorithms are now recommended for standard use. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*Ciphers\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "Ciphers aes128-ctr,aes192-ctr,aes256-ctr,chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Use Only Strong Key Exchange algorithms
[ref]ruleLimit the Key Exchange to strong algorithms.
The following line in /etc/ssh/sshd_config demonstrates use
of those:
KexAlgorithms curve25519-sha256,curve25519-sha256@libssh.org,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,diffie-hellman-group-exchange-sha256 Rationale:Key exchange is any method in cryptography by which cryptographic keys are exchanged
between two parties, allowing use of a cryptographic algorithm. If the sender and receiver
wish to exchange encrypted messages, each must be equipped to encrypt messages to be
sent and decrypt messages received Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
sshd_strong_kex='curve25519-sha256,curve25519-sha256@libssh.org,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,diffie-hellman-group-exchange-sha256'
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*KexAlgorithms\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "KexAlgorithms $sshd_strong_kex" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92626-1
- PCI-DSS-Req-2.3
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.7
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_use_strong_kex
- name: XCCDF Value sshd_strong_kex # promote to variable
set_fact:
sshd_strong_kex: !!str curve25519-sha256,curve25519-sha256@libssh.org,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,diffie-hellman-group-exchange-sha256
tags:
- always
- name: Use Only Strong Key Exchange algorithms
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*KexAlgorithms\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*KexAlgorithms\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*KexAlgorithms\s+
line: KexAlgorithms {{ sshd_strong_kex }}
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92626-1
- PCI-DSS-Req-2.3
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.7
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_use_strong_kex
|
Use Only Strong MACs
[ref]ruleLimit the MACs to strong hash algorithms.
The following line in /etc/ssh/sshd_config demonstrates use
of those MACs:
MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-512,hmac-sha2-256 Rationale:MD5 and 96-bit MAC algorithms are considered weak and have been shown to increase
exploitability in SSH downgrade attacks. Weak algorithms continue to have a great deal of
attention as a weak spot that can be exploited with expanded computing power. An
attacker that breaks the algorithm could take advantage of a MiTM position to decrypt the
SSH tunnel and capture credentials and information Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
sshd_strong_macs='hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-512,hmac-sha2-256'
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*MACs\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"
cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "MACs $sshd_strong_macs" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91396-2
- NIST-800-53-AC-17 (2)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_use_strong_macs
- name: XCCDF Value sshd_strong_macs # promote to variable
set_fact:
sshd_strong_macs: !!str hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-512,hmac-sha2-256
tags:
- always
- name: Use Only Strong MACs
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MACs\s+
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MACs\s+
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/ssh/sshd_config
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*MACs\s+
line: MACs {{ sshd_strong_macs }}
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91396-2
- NIST-800-53-AC-17 (2)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_use_strong_macs
|
Verify Group Who Owns SSH Server config file
[ref]rule
To properly set the group owner of /etc/ssh/sshd_config, run the command:
$ sudo chgrp root /etc/ssh/sshd_config
Rationale:Service configuration files enable or disable features of their respective
services that if configured incorrectly can lead to insecure and vulnerable
configurations. Therefore, service configuration files should be owned by the
correct group to prevent unauthorized changes. Identifiers:
CCE-91392-1 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.2.1, R50, SLES-15-600150015 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/ssh/sshd_config" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/ssh/sshd_config
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91392-1
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_groupowner_sshd_config
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_groupowner_sshd_config_newgroup variable if represented by gid
ansible.builtin.set_fact:
file_groupowner_sshd_config_newgroup: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91392-1
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_groupowner_sshd_config
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/ssh/sshd_config
ansible.builtin.stat:
path: /etc/ssh/sshd_config
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91392-1
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_groupowner_sshd_config
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/ssh/sshd_config
ansible.builtin.file:
path: /etc/ssh/sshd_config
follow: false
group: '{{ file_groupowner_sshd_config_newgroup }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91392-1
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_groupowner_sshd_config
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Owner on SSH Server config file
[ref]rule
To properly set the owner of /etc/ssh/sshd_config, run the command:
$ sudo chown root /etc/ssh/sshd_config
Rationale:Service configuration files enable or disable features of their respective
services that if configured incorrectly can lead to insecure and vulnerable
configurations. Therefore, service configuration files should be owned by the
correct group to prevent unauthorized changes. Identifiers:
CCE-91393-9 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.2.1, R50, SLES-15-600150015 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/ssh/sshd_config" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/ssh/sshd_config
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91393-9
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_owner_sshd_config
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_owner_sshd_config_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_sshd_config_newown: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91393-9
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_owner_sshd_config
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/ssh/sshd_config
ansible.builtin.stat:
path: /etc/ssh/sshd_config
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91393-9
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_owner_sshd_config
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/ssh/sshd_config
ansible.builtin.file:
path: /etc/ssh/sshd_config
follow: false
owner: '{{ file_owner_sshd_config_newown }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91393-9
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure_strategy
- file_owner_sshd_config
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on SSH Server config file
[ref]rule
To properly set the permissions of /etc/ssh/sshd_config, run the command:
$ sudo chmod 0600 /etc/ssh/sshd_config Rationale:Service configuration files enable or disable features of their respective
services that if configured incorrectly can lead to insecure and vulnerable
configurations. Therefore, service configuration files should be owned by the
correct group to prevent unauthorized changes. Identifiers:
CCE-91306-1 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.2.1, R50, SLES-15-600150015, 2.2.6, 2.2 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
chmod u-xs,g-xwrs,o-xwrt /etc/ssh/sshd_config
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91306-1
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_sshd_config
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/ssh/sshd_config
ansible.builtin.stat:
path: /etc/ssh/sshd_config
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91306-1
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_sshd_config
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xwrs,o-xwrt on /etc/ssh/sshd_config
ansible.builtin.file:
path: /etc/ssh/sshd_config
mode: u-xs,g-xwrs,o-xwrt
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-91306-1
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_sshd_config
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify Permissions on SSH Server Private *_key Key Files
[ref]ruleSSH server private keys - files that match the /etc/ssh/*_key glob, have to have restricted permissions.
If those files are owned by the root user and the root group, they have to have the 0640 permission or stricter. Warning:
Remediation is not possible at bootable container build time because SSH host
keys are generated post-deployment. Rationale:If an unauthorized user obtains the private SSH host key file, the host could be
impersonated. Identifiers:
CCE-85644-3 References:
12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.1.13, 3.13.10, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-2.2.4, SRG-OS-000480-GPOS-00227, SLES-15-040250, 5.2.2, R50, SLES-15-600150030, 1449, 2.2.6, 2.2, SV-235009r991589_rule Remediation Puppet snippet: (show)
include ssh_private_key_perms
class ssh_private_key_perms {
exec { 'sshd_priv_key':
command => "chmod 0640 /etc/ssh/*_key",
path => '/bin:/usr/bin'
}
}
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
for keyfile in /etc/ssh/*_key; do
test -f "$keyfile" || continue
if test root:root = "$(stat -c "%U:%G" "$keyfile")"; then
chmod u-xs,g-xws,o-xwrt "$keyfile"
else
echo "Key-like file '$keyfile' is owned by an unexpected user:group combination"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85644-3
- DISA-STIG-SLES-15-040250
- NIST-800-171-3.1.13
- NIST-800-171-3.13.10
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-2.2.4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_sshd_private_key
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find root:root-owned keys
ansible.builtin.command: find -H /etc/ssh/ -maxdepth 1 -user root -regex ".*_key$"
-type f -group root -perm /u+xs,g+xws,o+xwrt
register: root_owned_keys
changed_when: false
failed_when: false
check_mode: false
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85644-3
- DISA-STIG-SLES-15-040250
- NIST-800-171-3.1.13
- NIST-800-171-3.13.10
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-2.2.4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_sshd_private_key
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set permissions for root:root-owned keys
ansible.builtin.file:
path: '{{ item }}'
mode: u-xs,g-xws,o-xwrt
state: file
with_items:
- '{{ root_owned_keys.stdout_lines }}'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85644-3
- DISA-STIG-SLES-15-040250
- NIST-800-171-3.1.13
- NIST-800-171-3.13.10
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-2.2.4
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_sshd_private_key
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
X Window System
[ref]groupThe X Window System implementation included with the
system is called X.org. |
| contains 2 rules |
Disable X Windows
[ref]groupUnless there is a mission-critical reason for the
system to run a graphical user interface, ensure X is not set to start
automatically at boot and remove the X Windows software packages.
There is usually no reason to run X Windows
on a dedicated server system, as it increases the system's attack surface and consumes
system resources. Administrators of server systems should instead login via
SSH or on the text console. |
| contains 2 rules |
Remove the X Windows Package Group
[ref]ruleBy removing the xorg-x11-server-common package, the system no longer has X Windows
installed. If X Windows is not installed then the system cannot boot into graphical user mode.
This prevents the system from being accidentally or maliciously booted into a graphical.target
mode. To do so, run the following command:
$ sudo zypper groupremove "X Window System"
$ sudo zypper remove xorg-x11-server-common Warning:
The installation and use of a Graphical User Interface (GUI) increases your attack vector and decreases your
overall security posture. Removing the package xorg-x11-server-common package will remove the graphical target
which might bring your system to an inconsistent state requiring additional configuration to access the system
again. If a GUI is an operational requirement, a tailored profile that removes this rule should used before
continuing installation. Rationale:Unnecessary service packages must not be installed to decrease the attack surface of the system. X windows has a long history of security
vulnerabilities and should not be installed unless approved and documented. Identifiers:
CCE-91361-6 References:
12, 15, 8, APO13.01, DSS01.04, DSS05.02, DSS05.03, 4.3.3.6.6, SR 1.13, SR 2.6, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.13.1.1, A.13.2.1, A.14.1.3, A.6.2.1, A.6.2.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.PT-4, SRG-OS-000480-GPOS-00227, 2.2.2, SLES-15-300150315 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_xorg-x11-server-common
class remove_xorg-x11-server-common {
package { 'xorg-x11-server-common':
ensure => 'purged',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove xorg-x11-server-common
# from the system, and may remove any packages
# that depend on xorg-x11-server-common. Execute this
# remediation AFTER testing on a non-production
# system!
zypper remove -y "xorg-x11-server-common"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Remove the X Windows Package Group: Ensure xorg-x11-server-common is removed'
ansible.builtin.package:
name: xorg-x11-server-common
state: absent
tags:
- CCE-91361-6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_xorg-x11-server-common_removed
|
Disable graphical user interface
[ref]ruleBy removing the following packages, the system no longer has X Windows installed.
xorg-x11-server
xorg-x11-server-extra
xorg-x11-server-Xvfb
xwayland
If X Windows is not installed then the system cannot boot into graphical user mode.
This prevents the system from being accidentally or maliciously booted into a graphical.target
mode. To do so, run the following command:
sudo zypper remove xorg-x11-server xorg-x11-server-extra xorg-x11-server-Xvfb xwayland Warning:
The installation and use of a Graphical User Interface (GUI) increases your attack vector and decreases your
overall security posture. Removing the package xorg-x11-server-common package will remove the graphical target
which might bring your system to an inconsistent state requiring additional configuration to access the system
again.
The rule xwindows_runlevel_target can be used to configure the system to boot into the multi-user.target.
If a GUI is an operational requirement, a tailored profile that removes this rule should be used before
continuing installation. Rationale:Unnecessary service packages must not be installed to decrease the attack surface of the system.
X windows has a long history of security vulnerabilities and should not be installed unless approved and documented. Remediation Anaconda snippet: (show)
# remove packages
package --remove=xorg-x11-server
package --remove=xorg-x11-server-extra
package --remove=xorg-x11-server-Xvfb
package --remove=xwayland
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
# remove packages
zypper remove -y "xorg-x11-server"
zypper remove -y "xorg-x11-server-extra"
zypper remove -y "xorg-x11-server-Xvfb"
zypper remove -y "xwayland"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Disable graphical user interface - Ensure xorg-x11-server is removed
ansible.builtin.package:
name: xorg-x11-server
state: absent
tags:
- CCE-91362-4
- NIST-800-53-CM-6(b)
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- xwindows_remove_packages
- name: Disable graphical user interface - Ensure xorg-x11-server-extra is removed
ansible.builtin.package:
name: xorg-x11-server-extra
state: absent
tags:
- CCE-91362-4
- NIST-800-53-CM-6(b)
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- xwindows_remove_packages
- name: Disable graphical user interface - Ensure xorg-x11-server-Xvfb is removed
ansible.builtin.package:
name: xorg-x11-server-Xvfb
state: absent
tags:
- CCE-91362-4
- NIST-800-53-CM-6(b)
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- xwindows_remove_packages
- name: Disable graphical user interface - Ensure xwayland is removed
ansible.builtin.package:
name: xwayland
state: absent
tags:
- CCE-91362-4
- NIST-800-53-CM-6(b)
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- xwindows_remove_packages
|
System Accounting with auditd
[ref]groupThe audit service provides substantial capabilities
for recording system activities. By default, the service audits about
SELinux AVC denials and certain types of security-relevant events
such as system logins, account modifications, and authentication
events performed by programs such as sudo.
Under its default configuration, auditd has modest disk space
requirements, and should not noticeably impact system performance.
NOTE: The Linux Audit daemon auditd can be configured to use
the augenrules program to read audit rules files (*.rules)
located in /etc/audit/rules.d location and compile them to create
the resulting form of the /etc/audit/audit.rules configuration file
during the daemon startup (default configuration). Alternatively, the auditd
daemon can use the auditctl utility to read audit rules from the
/etc/audit/audit.rules configuration file during daemon startup,
and load them into the kernel. The expected behavior is configured via the
appropriate ExecStartPost directive setting in the
/usr/lib/systemd/system/auditd.service configuration file.
To instruct the auditd daemon to use the augenrules program
to read audit rules (default configuration), use the following setting:
ExecStartPost=-/sbin/augenrules --load
in the /usr/lib/systemd/system/auditd.service configuration file.
In order to instruct the auditd daemon to use the auditctl
utility to read audit rules, use the following setting:
ExecStartPost=-/sbin/auditctl -R /etc/audit/audit.rules
in the /usr/lib/systemd/system/auditd.service configuration file.
Refer to [Service] section of the /usr/lib/systemd/system/auditd.service
configuration file for further details.
Government networks often have substantial auditing
requirements and auditd can be configured to meet these
requirements.
Examining some example audit records demonstrates how the Linux audit system
satisfies common requirements.
The following example from Red Hat Enterprise Linux 7 Documentation available at
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html-single/selinux_users_and_administrators_guide/index#sect-Security-Enhanced_Linux-Fixing_Problems-Raw_Audit_Messages
shows the substantial amount of information captured in a
two typical "raw" audit messages, followed by a breakdown of the most important
fields. In this example the message is SELinux-related and reports an AVC
denial (and the associated system call) that occurred when the Apache HTTP
Server attempted to access the /var/www/html/file1 file (labeled with
the samba_share_t type):
type=AVC msg=audit(1226874073.147:96): avc: denied { getattr } for pid=2465 comm="httpd"
path="/var/www/html/file1" dev=dm-0 ino=284133 scontext=unconfined_u:system_r:httpd_t:s0
tcontext=unconfined_u:object_r:samba_share_t:s0 tclass=file
type=SYSCALL msg=audit(1226874073.147:96): arch=40000003 syscall=196 success=no exit=-13
a0=b98df198 a1=bfec85dc a2=54dff4 a3=2008171 items=0 ppid=2463 pid=2465 auid=502 uid=48
gid=48 euid=48 suid=48 fsuid=48 egid=48 sgid=48 fsgid=48 tty=(none) ses=6 comm="httpd"
exe="/usr/sbin/httpd" subj=unconfined_u:system_r:httpd_t:s0 key=(null)
msg=audit(1226874073.147:96)- The number in parentheses is the unformatted time stamp (Epoch time)
for the event, which can be converted to standard time by using the
date command.
{ getattr }- The item in braces indicates the permission that was denied.
getattr
indicates the source process was trying to read the target file's status information.
This occurs before reading files. This action is denied due to the file being
accessed having the wrong label. Commonly seen permissions include getattr,
read, and write.
comm="httpd"- The executable that launched the process. The full path of the executable is
found in the
exe= section of the system call (SYSCALL) message,
which in this case, is exe="/usr/sbin/httpd".
path="/var/www/html/file1"- The path to the object (target) the process attempted to access.
scontext="unconfined_u:system_r:httpd_t:s0"- The SELinux context of the process that attempted the denied action. In
this case, it is the SELinux context of the Apache HTTP Server, which is running
in the
httpd_t domain.
tcontext="unconfined_u:object_r:samba_share_t:s0"- The SELinux context of the object (target) the process attempted to access.
In this case, it is the SELinux context of
file1. Note: the samba_share_t
type is not accessible to processes running in the httpd_t domain.
- From the system call (
SYSCALL) message, two items are of interest:
success=no: indicates whether the denial (AVC) was enforced or not.
success=no indicates the system call was not successful (SELinux denied
access). success=yes indicates the system call was successful - this can
be seen for permissive domains or unconfined domains, such as initrc_t
and kernel_t.
exe="/usr/sbin/httpd": the full path to the executable that launched
the process, which in this case, is exe="/usr/sbin/httpd".
|
| contains 82 rules |
Configure auditd Rules for Comprehensive Auditing
[ref]groupThe auditd program can perform comprehensive
monitoring of system activity. This section describes recommended
configuration settings for comprehensive auditing, but a full
description of the auditing system's capabilities is beyond the
scope of this guide. The mailing list linux-audit@redhat.com exists
to facilitate community discussion of the auditing system.
The audit subsystem supports extensive collection of events, including:
- Tracing of arbitrary system calls (identified by name or number)
on entry or exit.
- Filtering by PID, UID, call success, system call argument (with
some limitations), etc.
- Monitoring of specific files for modifications to the file's
contents or metadata.
Auditing rules at startup are controlled by the file /etc/audit/audit.rules.
Add rules to it to meet the auditing requirements for your organization.
Each line in /etc/audit/audit.rules represents a series of arguments
that can be passed to auditctl and can be individually tested
during runtime. See documentation in /usr/share/doc/audit-VERSION and
in the related man pages for more details.
If copying any example audit rulesets from /usr/share/doc/audit-VERSION,
be sure to comment out the
lines containing arch= which are not appropriate for your system's
architecture. Then review and understand the following rules,
ensuring rules are activated as needed for the appropriate
architecture.
After reviewing all the rules, reading the following sections, and
editing as needed, the new rules can be activated as follows:
$ sudo service auditd restart |
| contains 69 rules |
Record Events that Modify the System's Discretionary Access Controls
[ref]groupAt a minimum, the audit system should collect file permission
changes for all users and root. Note that the "-F arch=b32" lines should be
present even on a 64 bit system. These commands identify system calls for
auditing. Even if the system is 64 bit it can still execute 32 bit system
calls. Additionally, these rules can be configured in a number of ways while
still achieving the desired effect. An example of this is that the "-S" calls
could be split up and placed on separate lines, however, this is less efficient.
Add the following to /etc/audit/audit.rules:
-a always,exit -F arch=b32 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
-a always,exit -F arch=b32 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
-a always,exit -F arch=b32 -S setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If your system is 64 bit then these lines should be duplicated and the
arch=b32 replaced with arch=b64 as follows:
-a always,exit -F arch=b64 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
-a always,exit -F arch=b64 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
-a always,exit -F arch=b64 -S setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod |
| contains 13 rules |
Record Events that Modify the System's Discretionary Access Controls - chmod
[ref]ruleAt a minimum, the audit system should collect file permission
changes for all users and root. If the auditd daemon is configured to
use the augenrules program to read audit rules during daemon startup
(the default), add the following line to a file with suffix .rules in
the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:The changing of file permissions could indicate that a user is attempting to
gain access to information that would otherwise be disallowed. Auditing DAC modifications
can facilitate the identification of patterns of abuse among both authorized and
unauthorized users. Identifiers:
CCE-85693-0 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-3, AU-3.1, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SLES-15-030290, 4.1.9, R73, SLES-15-750450255, 0582, 10.3.4, 10.3, SV-234928r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ); }; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="chmod"
KEY="perm_mod"
SYSCALL_GROUPING="chmod fchmod fchmodat"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85693-0
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030290
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_chmod
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit chmod tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85693-0
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030290
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_chmod
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for chmod for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- chmod
syscall_grouping:
- chmod
- fchmod
- fchmodat
- name: Check existence of chmod in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- chmod
syscall_grouping:
- chmod
- fchmod
- fchmodat
- name: Check existence of chmod in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
tags:
- CCE-85693-0
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030290
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_chmod
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for chmod for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- chmod
syscall_grouping:
- chmod
- fchmod
- fchmodat
- name: Check existence of chmod in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- chmod
syscall_grouping:
- chmod
- fchmod
- fchmodat
- name: Check existence of chmod in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- audit_arch == "b64"
tags:
- CCE-85693-0
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030290
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_chmod
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Discretionary Access Controls - chown
[ref]ruleAt a minimum, the audit system should collect file permission
changes for all users and root. If the auditd daemon is configured to
use the augenrules program to read audit rules during daemon startup
(the default), add the following line to a file with suffix .rules in
the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:The changing of file permissions could indicate that a user is attempting to
gain access to information that would otherwise be disallowed. Auditing DAC modifications
can facilitate the identification of patterns of abuse among both authorized and
unauthorized users. Identifiers:
CCE-85690-6 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-3, AU-3.1, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219, SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SLES-15-030250, 4.1.9, R73, SLES-15-750450255, 0582, 10.3.4, 10.3, SV-234924r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ); }; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="chown"
KEY="perm_mod"
SYSCALL_GROUPING="chown fchown fchownat lchown"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85690-6
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_chown
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit chown tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85690-6
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_chown
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for chown for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- chown
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of chown in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- chown
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of chown in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
tags:
- CCE-85690-6
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_chown
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for chown for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- chown
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of chown in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- chown
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of chown in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- audit_arch == "b64"
tags:
- CCE-85690-6
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_chown
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Discretionary Access Controls - fchmod
[ref]ruleAt a minimum, the audit system should collect file permission
changes for all users and root. If the auditd daemon is configured to
use the augenrules program to read audit rules during daemon startup
(the default), add the following line to a file with suffix .rules in
the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:The changing of file permissions could indicate that a user is attempting to
gain access to information that would otherwise be disallowed. Auditing DAC modifications
can facilitate the identification of patterns of abuse among both authorized and
unauthorized users. Identifiers:
CCE-85694-8 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-3, AU-3.1, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SLES-15-030290, 4.1.9, R73, SLES-15-750450255, 10.3.4, 10.3, SV-234928r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="fchmod"
KEY="perm_mod"
SYSCALL_GROUPING="chmod fchmod fchmodat"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85694-8
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030290
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchmod
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit fchmod tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85694-8
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030290
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchmod
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for fchmod for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchmod
syscall_grouping:
- chmod
- fchmod
- fchmodat
- name: Check existence of fchmod in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchmod
syscall_grouping:
- chmod
- fchmod
- fchmodat
- name: Check existence of fchmod in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85694-8
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030290
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchmod
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for fchmod for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchmod
syscall_grouping:
- chmod
- fchmod
- fchmodat
- name: Check existence of fchmod in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchmod
syscall_grouping:
- chmod
- fchmod
- fchmodat
- name: Check existence of fchmod in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85694-8
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030290
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchmod
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Discretionary Access Controls - fchmodat
[ref]ruleAt a minimum, the audit system should collect file permission
changes for all users and root. If the auditd daemon is configured to
use the augenrules program to read audit rules during daemon startup
(the default), add the following line to a file with suffix .rules in
the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:The changing of file permissions could indicate that a user is attempting to
gain access to information that would otherwise be disallowed. Auditing DAC modifications
can facilitate the identification of patterns of abuse among both authorized and
unauthorized users. Identifiers:
CCE-85695-5 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-3, AU-3.1, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SLES-15-030290, 4.1.9, R73, SLES-15-750450255, 10.3.4, 10.3, SV-234928r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="fchmodat"
KEY="perm_mod"
SYSCALL_GROUPING="chmod fchmod fchmodat"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85695-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030290
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchmodat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit fchmodat tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85695-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030290
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchmodat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for fchmodat for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchmodat
syscall_grouping:
- chmod
- fchmod
- fchmodat
- name: Check existence of fchmodat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchmodat
syscall_grouping:
- chmod
- fchmod
- fchmodat
- name: Check existence of fchmodat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85695-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030290
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchmodat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for fchmodat for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchmodat
syscall_grouping:
- chmod
- fchmod
- fchmodat
- name: Check existence of fchmodat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchmodat
syscall_grouping:
- chmod
- fchmod
- fchmodat
- name: Check existence of fchmodat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85695-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030290
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchmodat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Discretionary Access Controls - fchown
[ref]ruleAt a minimum, the audit system should collect file permission
changes for all users and root. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following line to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:The changing of file permissions could indicate that a user is attempting to
gain access to information that would otherwise be disallowed. Auditing DAC modifications
can facilitate the identification of patterns of abuse among both authorized and
unauthorized users. Identifiers:
CCE-85721-9 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-3, AU-3.1, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219, SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SLES-15-030250, 4.1.9, R73, SLES-15-750450255, 10.3.4, 10.3, SV-234924r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="fchown"
KEY="perm_mod"
SYSCALL_GROUPING="chown fchown fchownat lchown"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85721-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchown
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit fchown tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85721-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchown
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for fchown for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchown
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of fchown in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchown
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of fchown in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85721-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchown
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for fchown for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchown
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of fchown in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchown
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of fchown in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85721-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchown
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Discretionary Access Controls - fchownat
[ref]ruleAt a minimum, the audit system should collect file permission
changes for all users and root. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following line to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:The changing of file permissions could indicate that a user is attempting to
gain access to information that would otherwise be disallowed. Auditing DAC modifications
can facilitate the identification of patterns of abuse among both authorized and
unauthorized users. Identifiers:
CCE-85692-2 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-3, AU-3.1, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219, SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SLES-15-030250, 4.1.9, R73, SLES-15-750450255, 10.3.4, 10.3, SV-234924r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="fchownat"
KEY="perm_mod"
SYSCALL_GROUPING="chown fchown fchownat lchown"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85692-2
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchownat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit fchownat tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85692-2
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchownat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for fchownat for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchownat
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of fchownat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchownat
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of fchownat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85692-2
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchownat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for fchownat for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchownat
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of fchownat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fchownat
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of fchownat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85692-2
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fchownat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Discretionary Access Controls - fremovexattr
[ref]ruleAt a minimum, the audit system should collect file permission
changes for all users and root.
If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following line to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:The changing of file permissions could indicate that a user is attempting to
gain access to information that would otherwise be disallowed. Auditing DAC modifications
can facilitate the identification of patterns of abuse among both authorized and
unauthorized users. Identifiers:
CCE-85686-4 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-12(a), AU-12.1(ii), AU-12(c), AU-12.1(iv), AU-3, AU-3.1, MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000466-GPOS-00210, SRG-OS-000468-GPOS-00212, SRG-OS-000064-GPOS-00033, SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000499-CTR-001255, SLES-15-030190, 4.1.9, R73, SLES-15-750450255, 10.3.4, 10.3, SV-234918r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="fremovexattr"
KEY="perm_mod"
SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85686-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fremovexattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit fremovexattr tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85686-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fremovexattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for fremovexattr for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fremovexattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of fremovexattr in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fremovexattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of fremovexattr in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85686-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fremovexattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for fremovexattr for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fremovexattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of fremovexattr in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fremovexattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of fremovexattr in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85686-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fremovexattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Discretionary Access Controls - fsetxattr
[ref]ruleAt a minimum, the audit system should collect file permission
changes for all users and root. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following line to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:The changing of file permissions could indicate that a user is attempting to
gain access to information that would otherwise be disallowed. Auditing DAC modifications
can facilitate the identification of patterns of abuse among both authorized and
unauthorized users. Identifiers:
CCE-85688-0 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-12(a), AU-12.1(ii), AU-12(c), AU-12.1(iv), AU-3, AU-3.1, MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000466-GPOS-00210, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000064-GPOS-00033, SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270, SLES-15-030190, 4.1.9, R73, SLES-15-750450255, 10.3.4, 10.3, SV-234918r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="fsetxattr"
KEY="perm_mod"
SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85688-0
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fsetxattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit fsetxattr tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85688-0
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fsetxattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for fsetxattr for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fsetxattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of fsetxattr in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fsetxattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of fsetxattr in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85688-0
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fsetxattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for fsetxattr for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fsetxattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of fsetxattr in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- fsetxattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of fsetxattr in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85688-0
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_fsetxattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Discretionary Access Controls - lchown
[ref]ruleAt a minimum, the audit system should collect file permission
changes for all users and root. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following line to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:The changing of file permissions could indicate that a user is attempting to
gain access to information that would otherwise be disallowed. Auditing DAC modifications
can facilitate the identification of patterns of abuse among both authorized and
unauthorized users. Identifiers:
CCE-85691-4 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-3, AU-3.1, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219, SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SLES-15-030250, 4.1.9, R73, SLES-15-750450255, 10.3.4, 10.3, SV-234924r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ); }; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="lchown"
KEY="perm_mod"
SYSCALL_GROUPING="chown fchown fchownat lchown"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85691-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_lchown
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit lchown tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85691-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_lchown
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for lchown for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- lchown
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of lchown in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- lchown
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of lchown in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
tags:
- CCE-85691-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_lchown
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for lchown for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- lchown
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of lchown in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- lchown
syscall_grouping:
- chown
- fchown
- fchownat
- lchown
- name: Check existence of lchown in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- audit_arch == "b64"
tags:
- CCE-85691-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030250
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_lchown
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Discretionary Access Controls - lremovexattr
[ref]ruleAt a minimum, the audit system should collect file permission
changes for all users and root.
If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following line to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:The changing of file permissions could indicate that a user is attempting to
gain access to information that would otherwise be disallowed. Auditing DAC modifications
can facilitate the identification of patterns of abuse among both authorized and
unauthorized users. Identifiers:
CCE-85685-6 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-3, AU-3.1, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000466-GPOS-00210, SRG-OS-000064-GPOS-00033, SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000499-CTR-001255, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270, SLES-15-030190, 4.1.9, R73, SLES-15-750450255, 10.3.4, 10.3, SV-234918r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="lremovexattr"
KEY="perm_mod"
SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85685-6
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_lremovexattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit lremovexattr tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85685-6
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_lremovexattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for lremovexattr for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- lremovexattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of lremovexattr in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- lremovexattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of lremovexattr in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85685-6
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_lremovexattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for lremovexattr for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- lremovexattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of lremovexattr in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- lremovexattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of lremovexattr in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85685-6
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_lremovexattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Discretionary Access Controls - lsetxattr
[ref]ruleAt a minimum, the audit system should collect file permission
changes for all users and root. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following line to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:The changing of file permissions could indicate that a user is attempting to
gain access to information that would otherwise be disallowed. Auditing DAC modifications
can facilitate the identification of patterns of abuse among both authorized and
unauthorized users. Identifiers:
CCE-85689-8 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-12(a), AU-12.1(ii), AU-12(c), AU-12.1(iv), AU-3, AU-3.1, MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000466-GPOS-00210, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000064-GPOS-00033, SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270, SLES-15-030190, 4.1.9, R73, SLES-15-750450255, 10.3.4, 10.3, SV-234918r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="lsetxattr"
KEY="perm_mod"
SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85689-8
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_lsetxattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit lsetxattr tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85689-8
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_lsetxattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for lsetxattr for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- lsetxattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of lsetxattr in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- lsetxattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of lsetxattr in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85689-8
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_lsetxattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for lsetxattr for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- lsetxattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of lsetxattr in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- lsetxattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of lsetxattr in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85689-8
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_lsetxattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Discretionary Access Controls - removexattr
[ref]ruleAt a minimum, the audit system should collect file permission
changes for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following line to a file with suffix .rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:The changing of file permissions could indicate that a user is attempting to
gain access to information that would otherwise be disallowed. Auditing DAC modifications
can facilitate the identification of patterns of abuse among both authorized and
unauthorized users. Identifiers:
CCE-85684-9 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-12(a), AU-12.1(ii), AU-12(c), AU-12.1(iv), AU-3, AU-3.1, MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000466-GPOS-00210, SRG-OS-000064-GPOS-00033, SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000499-CTR-001255, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270, SLES-15-030190, 4.1.9, R73, SLES-15-750450255, 10.3.4, 10.3, SV-234918r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="removexattr"
KEY="perm_mod"
SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85684-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_removexattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit removexattr tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85684-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_removexattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for removexattr for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- removexattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of removexattr in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- removexattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of removexattr in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85684-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_removexattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for removexattr for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- removexattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of removexattr in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- removexattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of removexattr in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85684-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_removexattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Discretionary Access Controls - setxattr
[ref]ruleAt a minimum, the audit system should collect file permission
changes for all users and root. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following line to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:The changing of file permissions could indicate that a user is attempting to
gain access to information that would otherwise be disallowed. Auditing DAC modifications
can facilitate the identification of patterns of abuse among both authorized and
unauthorized users. Identifiers:
CCE-85687-2 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-3, AU-3.1, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SLES-15-030190, 4.1.9, R73, SLES-15-750450255, 10.3.4, 10.3, SV-234918r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="setxattr"
KEY="perm_mod"
SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85687-2
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_setxattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit setxattr tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85687-2
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_setxattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for setxattr for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- setxattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of setxattr in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- setxattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of setxattr in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85687-2
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_setxattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for setxattr for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- setxattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of setxattr in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- setxattr
syscall_grouping:
- fremovexattr
- lremovexattr
- removexattr
- fsetxattr
- lsetxattr
- setxattr
- name: Check existence of setxattr in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=perm_mod
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85687-2
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030190
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_dac_modification_setxattr
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Execution Attempts to Run ACL Privileged Commands
[ref]groupAt a minimum, the audit system should collect the execution of
ACL privileged commands for all users and root. |
| contains 2 rules |
Record Any Attempts to Run chacl
[ref]rule
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add a line of the
following form to /etc/audit/audit.rules:
-a always,exit -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged Rationale:Without generating audit records that are specific to the security and
mission needs of the organization, it would be difficult to establish,
correlate, and investigate the events relating to an incident or identify
those responsible for one.
Audit records can be generated from various components within the
information system (e.g., module or policy filter). Identifiers:
CCE-85595-7 References:
SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SLES-15-030440, SLES-15-750450375, SV-234943r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Retrieve hardware architecture of the underlying system
OTHER_FILTERS="-F path=/usr/bin/chacl -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
ACTION_ARCH_FILTERS="-a always,exit"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85595-7
- DISA-STIG-SLES-15-030440
- audit_rules_execution_chacl
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Any Attempts to Run chacl - Perform remediation of Audit rules for
/usr/bin/chacl
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/chacl -F perm=x -F
auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chacl -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
-S |,)\w+)+)( -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chacl -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85595-7
- DISA-STIG-SLES-15-030440
- audit_rules_execution_chacl
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Any Attempts to Run setfacl
[ref]rule
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add a line of the
following form to /etc/audit/audit.rules:
-a always,exit -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged Rationale:Without generating audit records that are specific to the security and
mission needs of the organization, it would be difficult to establish,
correlate, and investigate the events relating to an incident or identify
those responsible for one.
Audit records can be generated from various components within the
information system (e.g., module or policy filter). Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Retrieve hardware architecture of the underlying system
OTHER_FILTERS="-F path=/usr/bin/setfacl -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
ACTION_ARCH_FILTERS="-a always,exit"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85594-0
- DISA-STIG-SLES-15-030430
- audit_rules_execution_setfacl
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Any Attempts to Run setfacl - Perform remediation of Audit rules for
/usr/bin/setfacl
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/setfacl -F perm=x
-F auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/setfacl -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
-S |,)\w+)+)( -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/setfacl -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85594-0
- DISA-STIG-SLES-15-030430
- audit_rules_execution_setfacl
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Execution Attempts to Run SELinux Privileged Commands
[ref]groupAt a minimum, the audit system should collect the execution of
SELinux privileged commands for all users and root. |
| contains 1 rule |
Record Any Attempts to Run chcon
[ref]rule
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add a line of the
following form to /etc/audit/audit.rules:
-a always,exit -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged Rationale:Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised system accounts,
is a serious and ongoing concern and can have significant adverse impacts on organizations.
Auditing the use of privileged functions is one way to detect such misuse and identify
the risk from insider and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks,
which attempt to subvert their normal role of providing some necessary but
limited capability. As such, motivation exists to monitor these programs for
unusual activity. Identifiers:
CCE-85716-9 References:
1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, BAI03.05, DSS01.03, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.14.2.7, A.15.2.1, A.15.2.2, AU-3, AU-3.1, AU-12(a), AU-12.1(ii)AU-12.1(iv), MA-4(1)(a), DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.PT-1, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-APP-000495-CTR-001235, SRG-APP-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270, SLES-15-030450, SLES-15-750450345, 0582, SV-234944r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Retrieve hardware architecture of the underlying system
OTHER_FILTERS="-F path=/usr/bin/chcon -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
ACTION_ARCH_FILTERS="-a always,exit"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85716-9
- DISA-STIG-SLES-15-030450
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_execution_chcon
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Any Attempts to Run chcon - Perform remediation of Audit rules for
/usr/bin/chcon
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/chcon -F perm=x -F
auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chcon -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
-S |,)\w+)+)( -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chcon -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85716-9
- DISA-STIG-SLES-15-030450
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_execution_chcon
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record File Deletion Events by User
[ref]groupAt a minimum, the audit system should collect file deletion events
for all users and root. If the auditd daemon is configured to use the
augenrules program to read audit rules during daemon startup (the
default), add the following line to a file with suffix .rules in the
directory /etc/audit/rules.d, setting ARCH to either b32 for 32-bit
system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S rmdir,unlink,unlinkat,rename,renameat,renameat2 -F auid>=1000 -F auid!=unset -F key=delete
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file, setting ARCH to either b32 for 32-bit
system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S rmdir,unlink,unlinkat,rename,renameat,renameat2 -F auid>=1000 -F auid!=unset -F key=delete |
| contains 4 rules |
Ensure auditd Collects File Deletion Events by User - rename
[ref]ruleAt a minimum, the audit system should collect file deletion events
for all users and root. If the auditd daemon is configured to use the
augenrules program to read audit rules during daemon startup (the
default), add the following line to a file with suffix .rules in the
directory /etc/audit/rules.d, setting ARCH to either b32 for 32-bit
system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S rename -F auid>=1000 -F auid!=unset -F key=delete
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file, setting ARCH to either b32 for 32-bit
system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S rename -F auid>=1000 -F auid!=unset -F key=delete Rationale:Auditing file deletions will create an audit trail for files that are removed
from the system. The audit trail could aid in system troubleshooting, as well as, detecting
malicious processes that attempt to delete log files to conceal their presence. Identifiers:
CCE-85768-0 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.4, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.1.1, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.MA-2, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.7, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270, 4.1.13, R73, SLES-15-750450315, 10.2.1.7, 10.2.1, 10.2 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ); }; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="rename"
KEY="delete"
SYSCALL_GROUPING="unlink unlinkat rename renameat renameat2 rmdir"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85768-0
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_rename
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit rename tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85768-0
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_rename
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for rename for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- rename
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of rename in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- rename
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of rename in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
tags:
- CCE-85768-0
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_rename
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for rename for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- rename
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of rename in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- rename
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of rename in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- audit_arch == "b64"
tags:
- CCE-85768-0
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_rename
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Ensure auditd Collects File Deletion Events by User - renameat
[ref]ruleAt a minimum, the audit system should collect file deletion events
for all users and root. If the auditd daemon is configured to use the
augenrules program to read audit rules during daemon startup (the
default), add the following line to a file with suffix .rules in the
directory /etc/audit/rules.d, setting ARCH to either b32 for 32-bit
system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S renameat -F auid>=1000 -F auid!=unset -F key=delete
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file, setting ARCH to either b32 for 32-bit
system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S renameat -F auid>=1000 -F auid!=unset -F key=delete Rationale:Auditing file deletions will create an audit trail for files that are removed
from the system. The audit trail could aid in system troubleshooting, as well as, detecting
malicious processes that attempt to delete log files to conceal their presence. Identifiers:
CCE-85769-8 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.4, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.1.1, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.MA-2, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.7, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270, 4.1.13, R73, SLES-15-750450315, 10.2.1.7, 10.2.1, 10.2 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="renameat"
KEY="delete"
SYSCALL_GROUPING="unlink unlinkat rename renameat renameat2 rmdir"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85769-8
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_renameat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit renameat tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85769-8
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_renameat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for renameat for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- renameat
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of renameat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- renameat
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of renameat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85769-8
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_renameat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for renameat for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- renameat
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of renameat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- renameat
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of renameat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85769-8
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_renameat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Ensure auditd Collects File Deletion Events by User - unlink
[ref]ruleAt a minimum, the audit system should collect file deletion events
for all users and root. If the auditd daemon is configured to use the
augenrules program to read audit rules during daemon startup (the
default), add the following line to a file with suffix .rules in the
directory /etc/audit/rules.d, setting ARCH to either b32 for 32-bit
system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S unlink -F auid>=1000 -F auid!=unset -F key=delete
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file, setting ARCH to either b32 for 32-bit
system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S unlink -F auid>=1000 -F auid!=unset -F key=delete Rationale:Auditing file deletions will create an audit trail for files that are removed
from the system. The audit trail could aid in system troubleshooting, as well as, detecting
malicious processes that attempt to delete log files to conceal their presence. Identifiers:
CCE-85771-4 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.4, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.1.1, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.MA-2, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.7, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270, 4.1.13, R73, SLES-15-750450315, 10.2.1.7, 10.2.1, 10.2 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ); }; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="unlink"
KEY="delete"
SYSCALL_GROUPING="unlink unlinkat rename renameat renameat2 rmdir"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85771-4
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_unlink
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit unlink tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85771-4
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_unlink
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for unlink for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- unlink
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of unlink in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- unlink
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of unlink in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
tags:
- CCE-85771-4
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_unlink
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for unlink for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- unlink
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of unlink in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- unlink
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of unlink in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- audit_arch == "b64"
tags:
- CCE-85771-4
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_unlink
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Ensure auditd Collects File Deletion Events by User - unlinkat
[ref]ruleAt a minimum, the audit system should collect file deletion events
for all users and root. If the auditd daemon is configured to use the
augenrules program to read audit rules during daemon startup (the
default), add the following line to a file with suffix .rules in the
directory /etc/audit/rules.d, setting ARCH to either b32 for 32-bit
system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file, setting ARCH to either b32 for 32-bit
system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete Rationale:Auditing file deletions will create an audit trail for files that are removed
from the system. The audit trail could aid in system troubleshooting, as well as, detecting
malicious processes that attempt to delete log files to conceal their presence. Identifiers:
CCE-85772-2 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.4, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.1.1, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.MA-2, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.7, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270, 4.1.13, R73, SLES-15-750450315, 10.2.1.7, 10.2.1, 10.2 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="unlinkat"
KEY="delete"
SYSCALL_GROUPING="unlink unlinkat rename renameat renameat2 rmdir"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85772-2
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_unlinkat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit unlinkat tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85772-2
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_unlinkat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for unlinkat for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- unlinkat
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of unlinkat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- unlinkat
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of unlinkat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85772-2
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_unlinkat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for unlinkat for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- unlinkat
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of unlinkat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- unlinkat
syscall_grouping:
- unlink
- unlinkat
- rename
- renameat
- renameat2
- rmdir
- name: Check existence of unlinkat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=delete
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85772-2
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_file_deletion_events_unlinkat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Unauthorized Access Attempts Events to Files (unsuccessful)
[ref]groupAt a minimum, the audit system should collect unauthorized file
accesses for all users and root. Note that the "-F arch=b32" lines should be
present even on a 64 bit system. These commands identify system calls for
auditing. Even if the system is 64 bit it can still execute 32 bit system
calls. Additionally, these rules can be configured in a number of ways while
still achieving the desired effect. An example of this is that the "-S" calls
could be split up and placed on separate lines, however, this is less efficient.
Add the following to /etc/audit/audit.rules:
-a always,exit -F arch=b32 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If your system is 64 bit then these lines should be duplicated and the
arch=b32 replaced with arch=b64 as follows:
-a always,exit -F arch=b64 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access |
| contains 5 rules |
Record Unsuccessful Access Attempts to Files - creat
[ref]ruleAt a minimum, the audit system should collect unauthorized file
accesses for all users and root. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. Identifiers:
CCE-85681-5 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-3, AU-3.1, AU-12(a), AU-12.1(ii), AU-12(c), AU-12.1(iv), MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.4, Req-10.2.1, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205, SRG-APP-000495-CTR-001235, SLES-15-030150, 4.1.10, R73, SLES-15-750450225, 0582, 0846, SV-234914r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ); }; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="creat"
KEY="access"
SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS="-F exit=-EACCES"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS="-F exit=-EPERM"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85681-5
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_creat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit creat tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85681-5
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_creat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for creat EACCES for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- creat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of creat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- creat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of creat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
tags:
- CCE-85681-5
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_creat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for creat EACCES for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- creat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of creat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- creat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of creat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- audit_arch == "b64"
tags:
- CCE-85681-5
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_creat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for creat EPERM for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- creat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of creat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- creat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of creat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
tags:
- CCE-85681-5
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_creat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for creat EPERM for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- creat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of creat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- creat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of creat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- audit_arch == "b64"
tags:
- CCE-85681-5
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_creat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Unsuccessful Access Attempts to Files - ftruncate
[ref]ruleAt a minimum, the audit system should collect unauthorized file
accesses for all users and root. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. Identifiers:
CCE-85696-3 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-3, AU-3.1, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.4, Req-10.2.1, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205, SRG-APP-000495-CTR-001235, SLES-15-030150, 4.1.10, R73, SLES-15-750450225, 0582, 0846, SV-234914r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="ftruncate"
KEY="access"
SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS="-F exit=-EACCES"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS="-F exit=-EPERM"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85696-3
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_ftruncate
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit ftruncate tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85696-3
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_ftruncate
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for ftruncate EACCES for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- ftruncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of ftruncate in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- ftruncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of ftruncate in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85696-3
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_ftruncate
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for ftruncate EACCES for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- ftruncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of ftruncate in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- ftruncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of ftruncate in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85696-3
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_ftruncate
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for ftruncate EPERM for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- ftruncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of ftruncate in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- ftruncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of ftruncate in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85696-3
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_ftruncate
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for ftruncate EPERM for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- ftruncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of ftruncate in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- ftruncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of ftruncate in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85696-3
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_ftruncate
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Unsuccessful Access Attempts to Files - open
[ref]ruleAt a minimum, the audit system should collect unauthorized file
accesses for all users and root. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. Identifiers:
CCE-85680-7 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-12(c), AU-12.1(iv), AU-12(a), AU-12.1(ii), AU-3, AU-3.1, MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.4, Req-10.2.1, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205, SRG-APP-000495-CTR-001235, SLES-15-030150, 4.1.10, R73, SLES-15-750450225, 0582, 0846, SV-234914r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ); }; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="open"
KEY="access"
SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS="-F exit=-EACCES"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS="-F exit=-EPERM"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85680-7
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_open
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit open tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85680-7
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_open
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for open EACCES for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- open
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of open in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- open
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of open in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
tags:
- CCE-85680-7
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_open
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for open EACCES for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- open
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of open in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- open
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of open in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- audit_arch == "b64"
tags:
- CCE-85680-7
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_open
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for open EPERM for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- open
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of open in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- open
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of open in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
tags:
- CCE-85680-7
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_open
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for open EPERM for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- open
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of open in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- open
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of open in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not ( ansible_architecture == "aarch64" )
- audit_arch == "b64"
tags:
- CCE-85680-7
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_open
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Unsuccessful Access Attempts to Files - openat
[ref]ruleAt a minimum, the audit system should collect unauthorized file
accesses for all users and root. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. Identifiers:
CCE-85682-3 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-12(a), AU-12.1(ii), AU-12(c), AU-12.1(iv), AU-3, AU-3.1, MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.4, Req-10.2.1, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205, SRG-APP-000495-CTR-001235, SLES-15-030150, 4.1.10, R73, SLES-15-750450225, 0582, 0846, SV-234914r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="openat"
KEY="access"
SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS="-F exit=-EACCES"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS="-F exit=-EPERM"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85682-3
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_openat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit openat tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85682-3
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_openat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for openat EACCES for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- openat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of openat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- openat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of openat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85682-3
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_openat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for openat EACCES for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- openat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of openat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- openat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of openat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85682-3
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_openat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for openat EPERM for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- openat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of openat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- openat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of openat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85682-3
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_openat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for openat EPERM for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- openat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of openat in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- openat
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of openat in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85682-3
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_openat
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Unsuccessful Access Attempts to Files - truncate
[ref]ruleAt a minimum, the audit system should collect unauthorized file
accesses for all users and root. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Here the system calls
have been placed independent of other system calls. Grouping these system
calls with others as identifying earlier in this guide is more efficient. Rationale:Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. Identifiers:
CCE-85608-8 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.4, Req-10.2.1, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205, SRG-APP-000495-CTR-001235, SLES-15-030150, 4.1.10, R73, SLES-15-750450225, 0582, 0846, SV-234914r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="truncate"
KEY="access"
SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS="-F exit=-EACCES"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS="-F exit=-EPERM"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85608-8
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_truncate
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit truncate tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85608-8
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_truncate
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for truncate EACCES for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- truncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of truncate in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- truncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of truncate in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85608-8
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_truncate
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for truncate EACCES for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- truncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of truncate in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- truncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of truncate in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85608-8
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_truncate
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for truncate EPERM for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- truncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of truncate in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- truncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of truncate in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85608-8
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_truncate
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for truncate EPERM for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- truncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of truncate in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- truncate
syscall_grouping:
- creat
- ftruncate
- truncate
- open
- openat
- open_by_handle_at
- name: Check existence of truncate in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
-F auid>=1000 -F auid!=unset -F key=access
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85608-8
- DISA-STIG-SLES-15-030150
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.1
- PCI-DSS-Req-10.2.4
- audit_rules_unsuccessful_file_modification_truncate
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Information on Kernel Modules Loading and Unloading
[ref]groupTo capture kernel module loading and unloading events, use following lines, setting ARCH to
either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S init_module,delete_module -F key=modules
Place to add the lines depends on a way auditd daemon is configured. If it is configured
to use the augenrules program (the default), add the lines to a file with suffix
.rules in the directory /etc/audit/rules.d.
If the auditd daemon is configured to use the auditctl utility,
add the lines to file /etc/audit/audit.rules. |
| contains 3 rules |
Ensure auditd Collects Information on Kernel Module Loading and Unloading
[ref]ruleTo capture kernel module loading and unloading events, use following lines, setting ARCH to
either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S init_module,finit_module,delete_module -F key=modules
The place to add the lines depends on a way auditd daemon is configured. If it is configured
to use the augenrules program (the default), add the lines to a file with suffix
.rules in the directory /etc/audit/rules.d.
If the auditd daemon is configured to use the auditctl utility,
add the lines to file /etc/audit/audit.rules.Rationale:The addition/removal of kernel modules can be used to alter the behavior of
the kernel and potentially introduce malicious code into kernel space. It is important
to have an audit trail of modules that have been introduced into the kernel. Identifiers:
CCE-91247-7 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.7, 4.1.16, SLES-15-750450405, 0582 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
# Note: 32-bit and 64-bit kernel syscall numbers not always line up =>
# it's required on a 64-bit system to check also for the presence
# of 32-bit's equivalent of the corresponding rule.
# (See `man 7 audit.rules` for details )
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS=""
SYSCALL="init_module finit_module delete_module"
KEY="modules"
SYSCALL_GROUPING="init_module finit_module delete_module"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91247-7
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- audit_rules_kernel_module_loading
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-91247-7
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- audit_rules_kernel_module_loading
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for kernel module loading for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- init_module
- delete_module
- finit_module
syscall_grouping:
- init_module
- delete_module
- finit_module
- name: Check existence of init_module, delete_module, finit_module in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- init_module
- delete_module
- finit_module
syscall_grouping:
- init_module
- delete_module
- finit_module
- name: Check existence of init_module, delete_module, finit_module in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91247-7
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- audit_rules_kernel_module_loading
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for kernel module loading for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- init_module
- delete_module
- finit_module
syscall_grouping:
- init_module
- delete_module
- finit_module
- name: Check existence of init_module, delete_module, finit_module in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- init_module
- delete_module
- finit_module
syscall_grouping:
- init_module
- delete_module
- finit_module
- name: Check existence of init_module, delete_module, finit_module in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-91247-7
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- audit_rules_kernel_module_loading
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Ensure auditd Collects Information on Kernel Module Unloading - delete_module
[ref]rule
To capture kernel module loading and unloading events, use the following line, setting ARCH to
either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S delete_module -F key=modules
Place to add the line depends on a way auditd daemon is configured. If it is configured
to use the augenrules program (the default), add the line to a file with suffix
.rules in the directory /etc/audit/rules.d.
If the auditd daemon is configured to use the auditctl utility,
add the line to file /etc/audit/audit.rules.Rationale:The removal of kernel modules can be used to alter the behavior of
the kernel and potentially introduce malicious code into kernel space. It is important
to have an audit trail of modules that have been introduced into the kernel. Identifiers:
CCE-85748-2 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-3, AU-3.1, AU-12(a), AU-12.1(ii), AU-12.1(iv), MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.7, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222, SRG-APP-000495-CTR-001235, SRG-APP-000504-CTR-001280, SLES-15-030520, 4.1.16, R73, SLES-15-750450405, SV-234951r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
# Note: 32-bit and 64-bit kernel syscall numbers not always line up =>
# it's required on a 64-bit system to check also for the presence
# of 32-bit's equivalent of the corresponding rule.
# (See `man 7 audit.rules` for details )
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS=""
SYSCALL="delete_module"
KEY="modules"
SYSCALL_GROUPING="create_module delete_module finit_module init_module query_module"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85748-2
- DISA-STIG-SLES-15-030520
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.7
- audit_rules_kernel_module_loading_delete
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure auditd Collects Information on Kernel Module Unloading - delete_module
- Set architecture for audit ['delete_module'] tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85748-2
- DISA-STIG-SLES-15-030520
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.7
- audit_rules_kernel_module_loading_delete
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure auditd Collects Information on Kernel Module Unloading - delete_module
- Perform remediation of Audit rules for ['delete_module'] for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- delete_module
syscall_grouping:
- create_module
- delete_module
- finit_module
- init_module
- query_module
- name: Check existence of delete_module in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- delete_module
syscall_grouping:
- create_module
- delete_module
- finit_module
- init_module
- query_module
- name: Check existence of delete_module in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85748-2
- DISA-STIG-SLES-15-030520
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.7
- audit_rules_kernel_module_loading_delete
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure auditd Collects Information on Kernel Module Unloading - delete_module
- Perform remediation of Audit rules for ['delete_module'] for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- delete_module
syscall_grouping:
- create_module
- delete_module
- finit_module
- init_module
- query_module
- name: Check existence of delete_module in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- delete_module
syscall_grouping:
- create_module
- delete_module
- finit_module
- init_module
- query_module
- name: Check existence of delete_module in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85748-2
- DISA-STIG-SLES-15-030520
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.7
- audit_rules_kernel_module_loading_delete
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Ensure auditd Collects Information on Kernel Module Loading - init_module
[ref]rule
To capture kernel module loading and unloading events, use the following line, setting ARCH to
either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S init_module -F key=modules
Place to add the line depends on a way auditd daemon is configured. If it is configured
to use the augenrules program (the default), add the line to a file with suffix
.rules in the directory /etc/audit/rules.d.
If the auditd daemon is configured to use the auditctl utility,
add the line to file /etc/audit/audit.rules.Rationale:The addition of kernel modules can be used to alter the behavior of
the kernel and potentially introduce malicious code into kernel space. It is important
to have an audit trail of modules that have been introduced into the kernel. Identifiers:
CCE-85750-8 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-3, AU-3.1, AU-12(a), AU-12.1(ii), AU-12.1(iv), MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.7, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222, SRG-APP-000495-CTR-001235, SRG-APP-000504-CTR-001280, SLES-15-030530, 4.1.16, R73, SLES-15-750450405, SV-234952r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
# Note: 32-bit and 64-bit kernel syscall numbers not always line up =>
# it's required on a 64-bit system to check also for the presence
# of 32-bit's equivalent of the corresponding rule.
# (See `man 7 audit.rules` for details )
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS=""
SYSCALL="init_module"
KEY="modules"
SYSCALL_GROUPING="create_module delete_module finit_module init_module query_module"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85750-8
- DISA-STIG-SLES-15-030530
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.7
- audit_rules_kernel_module_loading_init
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure auditd Collects Information on Kernel Module Loading - init_module
- Set architecture for audit ['init_module'] tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85750-8
- DISA-STIG-SLES-15-030530
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.7
- audit_rules_kernel_module_loading_init
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure auditd Collects Information on Kernel Module Loading - init_module
- Perform remediation of Audit rules for ['init_module'] for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- init_module
syscall_grouping:
- create_module
- delete_module
- finit_module
- init_module
- query_module
- name: Check existence of init_module in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- init_module
syscall_grouping:
- create_module
- delete_module
- finit_module
- init_module
- query_module
- name: Check existence of init_module in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85750-8
- DISA-STIG-SLES-15-030530
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.7
- audit_rules_kernel_module_loading_init
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure auditd Collects Information on Kernel Module Loading - init_module
- Perform remediation of Audit rules for ['init_module'] for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- init_module
syscall_grouping:
- create_module
- delete_module
- finit_module
- init_module
- query_module
- name: Check existence of init_module in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- init_module
syscall_grouping:
- create_module
- delete_module
- finit_module
- init_module
- query_module
- name: Check existence of init_module in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85750-8
- DISA-STIG-SLES-15-030530
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.7
- audit_rules_kernel_module_loading_init
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Record Attempts to Alter Logon and Logout Events
[ref]groupThe audit system already collects login information for all users
and root. If the auditd daemon is configured to use the
augenrules program to read audit rules during daemon startup (the
default), add the following lines to a file with suffix .rules in the
directory /etc/audit/rules.d in order to watch for attempted manual
edits of files involved in storing logon events:
-w /var/log/tallylog -p wa -k logins
-w /var/log/faillock -p wa -k logins
-w /var/log/lastlog -p wa -k logins
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules file in order to watch for unattempted manual
edits of files involved in storing logon events:
-w /var/log/tallylog -p wa -k logins
-w /var/log/faillock -p wa -k logins
-w /var/log/lastlog -p wa -k logins |
| contains 3 rules |
Record Attempts to Alter Logon and Logout Events - faillog
[ref]ruleThe audit system already collects login information for all users
and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /var/log/faillog -p wa -k logins
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules:
-w /var/log/faillog -p wa -k logins Rationale:Manual editing of these files may indicate nefarious activity, such
as an attacker attempting to remove evidence of an intrusion. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/var/log/faillog" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/faillog $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/var/log/faillog$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /var/log/faillog -p wa -k logins" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/logins.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/log/faillog" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/logins.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/logins.rules"
# If the logins.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/var/log/faillog" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/faillog $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/var/log/faillog$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /var/log/faillog -p wa -k logins" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92576-8
- audit_rules_login_events_faillog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - faillog - Check if watch
rule for /var/log/faillog already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/var/log/faillog\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92576-8
- audit_rules_login_events_faillog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - faillog - Search /etc/audit/rules.d
for other rules with specified key logins
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)logins$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-92576-8
- audit_rules_login_events_faillog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - faillog - Use /etc/audit/rules.d/logins.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/logins.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-92576-8
- audit_rules_login_events_faillog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - faillog - Use matched file
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-92576-8
- audit_rules_login_events_faillog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - faillog - Add watch rule
for /var/log/faillog in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /var/log/faillog -p wa -k logins
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-92576-8
- audit_rules_login_events_faillog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - faillog - Check if watch
rule for /var/log/faillog already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/var/log/faillog\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92576-8
- audit_rules_login_events_faillog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - faillog - Add watch rule
for /var/log/faillog in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /var/log/faillog -p wa -k logins
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-92576-8
- audit_rules_login_events_faillog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Attempts to Alter Logon and Logout Events - lastlog
[ref]ruleThe audit system already collects login information for all users
and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /var/log/lastlog -p wa -k logins
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules:
-w /var/log/lastlog -p wa -k logins Rationale:Manual editing of these files may indicate nefarious activity, such
as an attacker attempting to remove evidence of an intrusion. Identifiers:
CCE-85598-1 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.3, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000473-GPOS-00218, SRG-OS-000470-GPOS-00214, SRG-APP-000495-CTR-001235, SRG-APP-000503-CTR-001275, SRG-APP-000506-CTR-001290, SLES-15-030480, 4.1.7, R73, SLES-15-750450300, 0582, 10.2.1.3, 10.2.1, 10.2, SV-234947r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/var/log/lastlog" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/lastlog $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/var/log/lastlog$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /var/log/lastlog -p wa -k logins" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/logins.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/log/lastlog" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/logins.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/logins.rules"
# If the logins.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/var/log/lastlog" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/lastlog $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/var/log/lastlog$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /var/log/lastlog -p wa -k logins" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85598-1
- DISA-STIG-SLES-15-030480
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_lastlog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - lastlog - Check if watch
rule for /var/log/lastlog already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/var/log/lastlog\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85598-1
- DISA-STIG-SLES-15-030480
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_lastlog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - lastlog - Search /etc/audit/rules.d
for other rules with specified key logins
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)logins$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85598-1
- DISA-STIG-SLES-15-030480
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_lastlog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - lastlog - Use /etc/audit/rules.d/logins.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/logins.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85598-1
- DISA-STIG-SLES-15-030480
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_lastlog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - lastlog - Use matched file
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85598-1
- DISA-STIG-SLES-15-030480
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_lastlog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - lastlog - Add watch rule
for /var/log/lastlog in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /var/log/lastlog -p wa -k logins
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85598-1
- DISA-STIG-SLES-15-030480
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_lastlog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - lastlog - Check if watch
rule for /var/log/lastlog already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/var/log/lastlog\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85598-1
- DISA-STIG-SLES-15-030480
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_lastlog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - lastlog - Add watch rule
for /var/log/lastlog in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /var/log/lastlog -p wa -k logins
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85598-1
- DISA-STIG-SLES-15-030480
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_lastlog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Attempts to Alter Logon and Logout Events - tallylog
[ref]ruleThe audit system already collects login information for all users
and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /var/log/tallylog -p wa -k logins
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules:
-w /var/log/tallylog -p wa -k logins Rationale:Manual editing of these files may indicate nefarious activity, such
as an attacker attempting to remove evidence of an intrusion. Identifiers:
CCE-85597-3 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.3, SRG-OS-000392-GPOS-00172, SRG-OS-000470-GPOS-00214, SRG-OS-000473-GPOS-00218, SRG-APP-000503-CTR-001275, SLES-15-030470, 4.1.7, SLES-15-750450300, 0582, 10.2.1.3, 10.2.1, 10.2, SV-234946r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/var/log/tallylog" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/tallylog $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/var/log/tallylog$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /var/log/tallylog -p wa -k logins" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/logins.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/log/tallylog" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/logins.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/logins.rules"
# If the logins.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/var/log/tallylog" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/tallylog $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/var/log/tallylog$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /var/log/tallylog -p wa -k logins" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85597-3
- DISA-STIG-SLES-15-030470
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_tallylog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - tallylog - Check if watch
rule for /var/log/tallylog already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/var/log/tallylog\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85597-3
- DISA-STIG-SLES-15-030470
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_tallylog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - tallylog - Search /etc/audit/rules.d
for other rules with specified key logins
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)logins$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85597-3
- DISA-STIG-SLES-15-030470
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_tallylog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - tallylog - Use /etc/audit/rules.d/logins.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/logins.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85597-3
- DISA-STIG-SLES-15-030470
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_tallylog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - tallylog - Use matched
file as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85597-3
- DISA-STIG-SLES-15-030470
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_tallylog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - tallylog - Add watch rule
for /var/log/tallylog in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /var/log/tallylog -p wa -k logins
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85597-3
- DISA-STIG-SLES-15-030470
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_tallylog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - tallylog - Check if watch
rule for /var/log/tallylog already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/var/log/tallylog\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85597-3
- DISA-STIG-SLES-15-030470
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_tallylog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - tallylog - Add watch rule
for /var/log/tallylog in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /var/log/tallylog -p wa -k logins
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85597-3
- DISA-STIG-SLES-15-030470
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_tallylog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Information on the Use of Privileged Commands
[ref]groupAt a minimum, the audit system should collect the execution of
privileged commands for all users and root. |
| contains 12 rules |
Ensure auditd Collects Information on the Use of Privileged Commands
[ref]ruleThe audit system should collect information about usage of privileged commands for all users.
These are commands with suid or sgid bits on and they are specially risky in local block
device partitions not mounted with noexec and nosuid options. Therefore, these partitions
should be first identified by the following command:
findmnt -n -l -k -it $(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,) | grep -Pv "noexec|nosuid"
For all partitions listed by the previous command, it is necessary to search for
setuid / setgid programs using the following command:
$ sudo find PARTITION -xdev -perm /6000 -type f 2>/dev/null
For each setuid / setgid program identified by the previous command, an audit rule must be
present in the appropriate place using the following line structure, setting ARCH to either b32 for 32-bit
system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -F path=PROG_PATH -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the augenrules program to read
audit rules during daemon startup, add the line to a file with suffix .rules in the
/etc/audit/rules.d directory, replacing the PROG_PATH part with the full path
of that setuid / setgid identified program.
If the auditd daemon is configured to use the auditctl utility instead, add
the line to the /etc/audit/audit.rules file, also replacing the PROG_PATH part
with the full path of that setuid / setgid identified program.Warning:
This rule checks for multiple syscalls related to privileged commands. If needed to check
specific privileged commands, other more specific rules should be considered. For example:
audit_rules_privileged_commands_suaudit_rules_privileged_commands_umountaudit_rules_privileged_commands_passwd
Warning:
Note that OVAL check and Bash / Ansible remediation of this rule
explicitly excludes file systems mounted at /proc directory
and its subdirectories. It is a virtual file system and it doesn't
contain executable applications. At the same time, interacting with this
file system during check or remediation caused undesirable errors. Rationale:Misuse of privileged functions, either intentionally or unintentionally by authorized users,
or by unauthorized external entities that have compromised system accounts, is a serious and
ongoing concern that can have significant adverse impacts on organizations.
Auditing the use of privileged functions is one way to detect such misuse and identify the
risk from insider and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert
their normal role of providing some necessary but limited capability. As such, motivation
exists to monitor these programs for unusual activity. Identifiers:
CCE-91251-9 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO08.04, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.05, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.5, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.3.4.5.9, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 3.9, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.1, A.16.1.2, A.16.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.3, A.6.2.1, A.6.2.2, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-2, DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, DE.DP-4, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, RS.CO-2, Req-10.2.2, SRG-OS-000327-GPOS-00127, 4.1.11, R73, SLES-15-750450210, 0582, 0846 Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
ACTION_ARCH_FILTERS="-a always,exit"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
function add_audit_rule()
{
local PRIV_CMD="$1"
local OTHER_FILTERS="-F path=$PRIV_CMD -F perm=x"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
}
if { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
PRIV_CMDS=$(find / -perm /6000 -type f -not -path "/sysroot/*" 2>/dev/null)
for PRIV_CMD in $PRIV_CMDS; do
add_audit_rule $PRIV_CMD
done
else
FILTER_NODEV=$(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,)
PARTITIONS=$(findmnt -n -l -k -it "$FILTER_NODEV" | grep -Pv "noexec|nosuid|/proc($|/.*$)" | awk '{ print $1 }')
for PARTITION in $PARTITIONS; do
PRIV_CMDS=$(find "${PARTITION}" -xdev -perm /6000 -type f 2>/dev/null)
for PRIV_CMD in $PRIV_CMDS; do
add_audit_rule $PRIV_CMD
done
done
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91251-9
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.2
- audit_rules_privileged_commands
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure auditd Collects Information on the Use of Privileged Commands - Set
List of Mount Points Which Permits Execution of Privileged Commands
ansible.builtin.set_fact:
privileged_mount_points: '{{ (ansible_facts.mounts | rejectattr(''options'', ''search'',
''noexec|nosuid'') | rejectattr(''mount'', ''match'', ''/proc($|/.*$)'') | map(attribute=''mount'')
| list ) }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91251-9
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.2
- audit_rules_privileged_commands
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure auditd Collects Information on the Use of Privileged Commands - Search
for Privileged Commands in Eligible Mount Points
ansible.builtin.shell:
cmd: find {{ item }} -xdev -perm /6000 -type f 2>/dev/null
register: result_privileged_commands_search
changed_when: false
failed_when: false
with_items: '{{ privileged_mount_points }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-91251-9
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.2
- audit_rules_privileged_commands
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure auditd Collects Information on the Use of Privileged Commands - Set
List of Privileged Commands Found in Eligible Mount Points
ansible.builtin.set_fact:
privileged_commands: '{{ privileged_commands | default([]) + item.stdout_lines
}}'
loop: '{{ result_privileged_commands_search.results }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- item is not skipped
tags:
- CCE-91251-9
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.2
- audit_rules_privileged_commands
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure auditd Collects Information on the Use of Privileged Commands - Privileged
Commands are Present in the System
block:
- name: Ensure auditd Collects Information on the Use of Privileged Commands - Ensure
Rules for All Privileged Commands in augenrules Format
ansible.builtin.lineinfile:
path: /etc/audit/rules.d/privileged.rules
line: -a always,exit -F path={{ item }} -F perm=x -F auid>=1000 -F auid!=unset
-F key=privileged
regexp: ^.*path={{ item | regex_escape() }} .*$
create: true
with_items:
- '{{ privileged_commands }}'
- name: Ensure auditd Collects Information on the Use of Privileged Commands - Ensure
Rules for All Privileged Commands in auditctl Format
ansible.builtin.lineinfile:
path: /etc/audit/audit.rules
line: -a always,exit -F path={{ item }} -F perm=x -F auid>=1000 -F auid!=unset
-F key=privileged
regexp: ^.*path={{ item | regex_escape() }} .*$
create: true
with_items:
- '{{ privileged_commands }}'
- name: Ensure auditd Collects Information on the Use of Privileged Commands - Search
for Duplicated Rules in Other Files
ansible.builtin.find:
paths: /etc/audit/rules.d
recurse: false
contains: ^-a always,exit -F path={{ item }} .*$
patterns: '*.rules'
with_items:
- '{{ privileged_commands }}'
register: result_augenrules_files
- name: Ensure auditd Collects Information on the Use of Privileged Commands - Ensure
Rules for Privileged Commands are Defined Only in One File
ansible.builtin.lineinfile:
path: '{{ item.1.path }}'
regexp: ^-a always,exit -F path={{ item.0.item }} .*$
state: absent
with_subelements:
- '{{ result_augenrules_files.results }}'
- files
when:
- item.1.path != '/etc/audit/rules.d/privileged.rules'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- privileged_commands is defined
tags:
- CCE-91251-9
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.2
- audit_rules_privileged_commands
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Ensure auditd Collects Information on the Use of Privileged Commands - chage
[ref]rule
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add a line of the
following form to /etc/audit/audit.rules:
-a always,exit -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged Rationale:Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised system accounts,
is a serious and ongoing concern and can have significant adverse impacts on organizations.
Auditing the use of privileged functions is one way to detect such misuse and identify
the risk from insider and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks,
which attempt to subvert their normal role of providing some necessary but
limited capability. As such, motivation exists to monitor these programs for
unusual activity. Identifiers:
CCE-85587-4 References:
1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, BAI03.05, DSS01.03, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.14.2.7, A.15.2.1, A.15.2.2, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.PT-1, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-APP-000029-CTR-000085, SRG-APP-000495-CTR-001235, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270, SLES-15-030120, SLES-15-750450465, SV-234911r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Retrieve hardware architecture of the underlying system
OTHER_FILTERS="-F path=/usr/bin/chage -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
ACTION_ARCH_FILTERS="-a always,exit"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85587-4
- DISA-STIG-SLES-15-030120
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- audit_rules_privileged_commands_chage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - chage
- Perform remediation of Audit rules for /usr/bin/chage
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/chage -F perm=x -F
auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chage -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
-S |,)\w+)+)( -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chage -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85587-4
- DISA-STIG-SLES-15-030120
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- audit_rules_privileged_commands_chage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure auditd Collects Information on the Use of Privileged Commands - chfn
[ref]rule
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/chfn -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add a line of the
following form to /etc/audit/audit.rules:
-a always,exit -F path=/usr/bin/chfn -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged Rationale:Without generating audit records that are specific to the security and
mission needs of the organization, it would be difficult to establish,
correlate, and investigate the events relating to an incident or identify
those responsible for one.
Audit records can be generated from various components within the
information system (e.g., module or policy filter). Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Retrieve hardware architecture of the underlying system
OTHER_FILTERS="-F path=/usr/bin/chfn -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
ACTION_ARCH_FILTERS="-a always,exit"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85589-0
- DISA-STIG-SLES-15-030340
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-3
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_chfn
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - chfn
- Perform remediation of Audit rules for /usr/bin/chfn
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/chfn -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/chfn -F perm=x -F
auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chfn -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/chfn -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
-S |,)\w+)+)( -F path=/usr/bin/chfn -F perm=x -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chfn -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85589-0
- DISA-STIG-SLES-15-030340
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-3
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_chfn
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure auditd Collects Information on the Use of Privileged Commands - chsh
[ref]rule
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/chsh -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add a line of the
following form to /etc/audit/audit.rules:
-a always,exit -F path=/usr/bin/chsh -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged Rationale:Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised system accounts,
is a serious and ongoing concern and can have significant adverse impacts on organizations.
Auditing the use of privileged functions is one way to detect such misuse and identify
the risk from insider and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks,
which attempt to subvert their normal role of providing some necessary but
limited capability. As such, motivation exists to monitor these programs for
unusual activity. Identifiers:
CCE-85586-6 References:
1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, BAI03.05, DSS01.03, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.14.2.7, A.15.2.1, A.15.2.2, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.PT-1, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-APP-000495-CTR-001235, SLES-15-030100, SLES-15-750450495, SV-234909r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Retrieve hardware architecture of the underlying system
OTHER_FILTERS="-F path=/usr/bin/chsh -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
ACTION_ARCH_FILTERS="-a always,exit"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85586-6
- DISA-STIG-SLES-15-030100
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- audit_rules_privileged_commands_chsh
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - chsh
- Perform remediation of Audit rules for /usr/bin/chsh
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/chsh -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/chsh -F perm=x -F
auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chsh -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/chsh -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
-S |,)\w+)+)( -F path=/usr/bin/chsh -F perm=x -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chsh -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85586-6
- DISA-STIG-SLES-15-030100
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- audit_rules_privileged_commands_chsh
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure auditd Collects Information on the Use of Privileged Commands - crontab
[ref]rule
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add a line of the
following form to /etc/audit/audit.rules:
-a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged Rationale:Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised system accounts,
is a serious and ongoing concern and can have significant adverse impacts on organizations.
Auditing the use of privileged functions is one way to detect such misuse and identify
the risk from insider and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks,
which attempt to subvert their normal role of providing some necessary but
limited capability. As such, motivation exists to monitor these programs for
unusual activity. Identifiers:
CCE-85588-2 References:
1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, BAI03.05, DSS01.03, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.14.2.7, A.15.2.1, A.15.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.PT-1, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-APP-000495-CTR-001235, SLES-15-030130, SLES-15-750450510, SV-234912r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Retrieve hardware architecture of the underlying system
OTHER_FILTERS="-F path=/usr/bin/crontab -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
ACTION_ARCH_FILTERS="-a always,exit"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85588-2
- DISA-STIG-SLES-15-030130
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- audit_rules_privileged_commands_crontab
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - crontab
- Perform remediation of Audit rules for /usr/bin/crontab
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/crontab -F perm=x
-F auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/crontab -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
-S |,)\w+)+)( -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/crontab -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85588-2
- DISA-STIG-SLES-15-030130
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- audit_rules_privileged_commands_crontab
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure auditd Collects Information on the Use of Privileged Commands - insmod
[ref]ruleAt a minimum, the audit system should collect the execution of
privileged commands for all users and root. If the auditd daemon is
configured to use the augenrules program to read audit rules during
daemon startup (the default), add a line of the following form to a file with
suffix .rules in the directory /etc/audit/rules.d:
-w /sbin/insmod -p x -k modules Rationale:Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised system accounts,
is a serious and ongoing concern and can have significant adverse impacts on organizations.
Auditing the use of privileged functions is one way to detect such misuse and identify
the risk from insider and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks,
which attempt to subvert their normal role of providing some necessary but
limited capability. As such, motivation exists to monitor these programs for
unusual activity. Identifiers:
CCE-85744-1 References:
AU-12(c), AU-12.1(iv), AU-3, AU-3.1, AU-12(a), AU-12.1(ii), MA-4(1)(a), SRG-OS-000037-GPOS-00015, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SLES-15-030380, 4.1.16, R73, SLES-15-750450405, SV-234937r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/sbin/insmod" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/sbin/insmod $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "x" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/sbin/insmod$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /sbin/insmod -p x -k modules" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/modules.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/sbin/insmod" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/modules.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/modules.rules"
# If the modules.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/sbin/insmod" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/sbin/insmod $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "x" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/sbin/insmod$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /sbin/insmod -p x -k modules" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85744-1
- DISA-STIG-SLES-15-030380
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_insmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - insmod
- Check if watch rule for /sbin/insmod already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/sbin/insmod\s+-p\s+x(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85744-1
- DISA-STIG-SLES-15-030380
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_insmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - insmod
- Search /etc/audit/rules.d for other rules with specified key modules
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)modules$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85744-1
- DISA-STIG-SLES-15-030380
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_insmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - insmod
- Use /etc/audit/rules.d/modules.rules as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/modules.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85744-1
- DISA-STIG-SLES-15-030380
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_insmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - insmod
- Use matched file as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85744-1
- DISA-STIG-SLES-15-030380
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_insmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - insmod
- Add watch rule for /sbin/insmod in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /sbin/insmod -p x -k modules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85744-1
- DISA-STIG-SLES-15-030380
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_insmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - insmod
- Check if watch rule for /sbin/insmod already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/sbin/insmod\s+-p\s+x(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85744-1
- DISA-STIG-SLES-15-030380
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_insmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - insmod
- Add watch rule for /sbin/insmod in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /sbin/insmod -p x -k modules
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85744-1
- DISA-STIG-SLES-15-030380
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_insmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure auditd Collects Information on the Use of Privileged Commands - modprobe
[ref]ruleAt a minimum, the audit system should collect the execution of
privileged commands for all users and root. If the auditd daemon is
configured to use the augenrules program to read audit rules during
daemon startup (the default), add a line of the following form to a file with
suffix .rules in the directory /etc/audit/rules.d:
-w /sbin/modprobe -p x -k modules
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add a line of the following
form to /etc/audit/audit.rules:
-w /sbin/modprobe -p x -k modules Rationale:Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised system accounts,
is a serious and ongoing concern and can have significant adverse impacts on organizations.
Auditing the use of privileged functions is one way to detect such misuse and identify
the risk from insider and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks,
which attempt to subvert their normal role of providing some necessary but
limited capability. As such, motivation exists to monitor these programs for
unusual activity. Identifiers:
CCE-85731-8 References:
AU-12(a), AU-12.1(ii), AU-3, AU-3.1, AU-12(c), AU-12.1(iv), MA-4(1)(a), SRG-OS-000037-GPOS-00015, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SLES-15-030400, 4.1.16, R73, SLES-15-750450405, SV-234939r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/sbin/modprobe" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/sbin/modprobe $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "x" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/sbin/modprobe$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /sbin/modprobe -p x -k modules" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/modules.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/sbin/modprobe" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/modules.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/modules.rules"
# If the modules.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/sbin/modprobe" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/sbin/modprobe $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "x" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/sbin/modprobe$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /sbin/modprobe -p x -k modules" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85731-8
- DISA-STIG-SLES-15-030400
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_modprobe
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - modprobe
- Check if watch rule for /sbin/modprobe already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/sbin/modprobe\s+-p\s+x(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85731-8
- DISA-STIG-SLES-15-030400
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_modprobe
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - modprobe
- Search /etc/audit/rules.d for other rules with specified key modules
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)modules$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85731-8
- DISA-STIG-SLES-15-030400
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_modprobe
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - modprobe
- Use /etc/audit/rules.d/modules.rules as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/modules.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85731-8
- DISA-STIG-SLES-15-030400
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_modprobe
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - modprobe
- Use matched file as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85731-8
- DISA-STIG-SLES-15-030400
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_modprobe
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - modprobe
- Add watch rule for /sbin/modprobe in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /sbin/modprobe -p x -k modules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85731-8
- DISA-STIG-SLES-15-030400
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_modprobe
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - modprobe
- Check if watch rule for /sbin/modprobe already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/sbin/modprobe\s+-p\s+x(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85731-8
- DISA-STIG-SLES-15-030400
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_modprobe
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - modprobe
- Add watch rule for /sbin/modprobe in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /sbin/modprobe -p x -k modules
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85731-8
- DISA-STIG-SLES-15-030400
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_modprobe
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure auditd Collects Information on the Use of Privileged Commands - newgrp
[ref]rule
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add a line of the
following form to /etc/audit/audit.rules:
-a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged Rationale:Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised system accounts,
is a serious and ongoing concern and can have significant adverse impacts on organizations.
Auditing the use of privileged functions is one way to detect such misuse and identify
the risk from insider and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks,
which attempt to subvert their normal role of providing some necessary but
limited capability. As such, motivation exists to monitor these programs for
unusual activity. Identifiers:
CCE-85585-8 References:
1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, BAI03.05, DSS01.03, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.14.2.7, A.15.2.1, A.15.2.2, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.PT-1, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-APP-000029-CTR-000085, SRG-APP-000495-CTR-001235, SLES-15-030090, SLES-15-750450525, SV-234908r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Retrieve hardware architecture of the underlying system
OTHER_FILTERS="-F path=/usr/bin/newgrp -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
ACTION_ARCH_FILTERS="-a always,exit"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85585-8
- DISA-STIG-SLES-15-030090
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- audit_rules_privileged_commands_newgrp
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - newgrp
- Perform remediation of Audit rules for /usr/bin/newgrp
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/newgrp -F perm=x -F
auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/newgrp -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
-S |,)\w+)+)( -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/newgrp -F perm=x
-F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85585-8
- DISA-STIG-SLES-15-030090
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- audit_rules_privileged_commands_newgrp
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure auditd Collects Information on the Use of Privileged Commands - rmmod
[ref]ruleAt a minimum, the audit system should collect the execution of
privileged commands for all users and root. If the auditd daemon is
configured to use the augenrules program to read audit rules during
daemon startup (the default), add a line of the following form to a file with
suffix .rules in the directory /etc/audit/rules.d:
-w /sbin/rmmod -p x -k modules Rationale:Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised system accounts,
is a serious and ongoing concern and can have significant adverse impacts on organizations.
Auditing the use of privileged functions is one way to detect such misuse and identify
the risk from insider and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks,
which attempt to subvert their normal role of providing some necessary but
limited capability. As such, motivation exists to monitor these programs for
unusual activity. Identifiers:
CCE-85732-6 References:
AU-12(c), AU-12.1(iv), AU-3, AU-3.1, AU-12(a), AU-12.1(ii), MA-4(1)(a), SRG-OS-000037-GPOS-00015, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SLES-15-030390, 4.1.16, R73, SLES-15-750450405, SV-234938r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/sbin/rmmod" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/sbin/rmmod $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "x" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/sbin/rmmod$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /sbin/rmmod -p x -k modules" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/modules.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/sbin/rmmod" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/modules.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/modules.rules"
# If the modules.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/sbin/rmmod" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/sbin/rmmod $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "x" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/sbin/rmmod$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /sbin/rmmod -p x -k modules" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85732-6
- DISA-STIG-SLES-15-030390
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_rmmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - rmmod
- Check if watch rule for /sbin/rmmod already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/sbin/rmmod\s+-p\s+x(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85732-6
- DISA-STIG-SLES-15-030390
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_rmmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - rmmod
- Search /etc/audit/rules.d for other rules with specified key modules
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)modules$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85732-6
- DISA-STIG-SLES-15-030390
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_rmmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - rmmod
- Use /etc/audit/rules.d/modules.rules as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/modules.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85732-6
- DISA-STIG-SLES-15-030390
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_rmmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - rmmod
- Use matched file as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85732-6
- DISA-STIG-SLES-15-030390
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_rmmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - rmmod
- Add watch rule for /sbin/rmmod in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /sbin/rmmod -p x -k modules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85732-6
- DISA-STIG-SLES-15-030390
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_rmmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - rmmod
- Check if watch rule for /sbin/rmmod already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/sbin/rmmod\s+-p\s+x(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85732-6
- DISA-STIG-SLES-15-030390
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_rmmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - rmmod
- Add watch rule for /sbin/rmmod in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /sbin/rmmod -p x -k modules
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85732-6
- DISA-STIG-SLES-15-030390
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- audit_rules_privileged_commands_rmmod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Any Attempts to Run ssh-agent
[ref]rule
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/ssh-agent -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add a line of the
following form to /etc/audit/audit.rules:
-a always,exit -F path=/usr/bin/ssh-agent -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged Rationale:Without generating audit records that are specific to the security and
mission needs of the organization, it would be difficult to establish,
correlate, and investigate the events relating to an incident or identify
those responsible for one.
Audit records can be generated from various components within the
information system (e.g., module or policy filter). Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Retrieve hardware architecture of the underlying system
OTHER_FILTERS="-F path=/usr/bin/ssh-agent -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
ACTION_ARCH_FILTERS="-a always,exit"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85590-8
- DISA-STIG-SLES-15-030370
- audit_rules_privileged_commands_ssh_agent
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Any Attempts to Run ssh-agent - Perform remediation of Audit rules
for /usr/bin/ssh-agent
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/ssh-agent -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/ssh-agent -F perm=x
-F auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/ssh-agent -F
perm=x -F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/bin/ssh-agent -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
-S |,)\w+)+)( -F path=/usr/bin/ssh-agent -F perm=x -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/ssh-agent -F
perm=x -F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85590-8
- DISA-STIG-SLES-15-030370
- audit_rules_privileged_commands_ssh_agent
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure auditd Collects Information on the Use of Privileged Commands - ssh-keysign
[ref]rule
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/lib/ssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add a line of the
following form to /etc/audit/audit.rules:
-a always,exit -F path=/usr/lib/ssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged Rationale:Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised system accounts,
is a serious and ongoing concern and can have significant adverse impacts on organizations.
Auditing the use of privileged functions is one way to detect such misuse and identify
the risk from insider and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks,
which attempt to subvert their normal role of providing some necessary but
limited capability. As such, motivation exists to monitor these programs for
unusual activity. Identifiers:
CCE-85582-5 References:
1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, BAI03.05, DSS01.03, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.14.2.7, A.15.2.1, A.15.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.PT-1, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-APP-000029-CTR-000085, SRG-APP-000495-CTR-001235, SLES-15-030060, SLES-15-750450705, SV-234905r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Retrieve hardware architecture of the underlying system
OTHER_FILTERS="-F path=/usr/lib/ssh/ssh-keysign -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
ACTION_ARCH_FILTERS="-a always,exit"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85582-5
- DISA-STIG-SLES-15-030060
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- audit_rules_privileged_commands_ssh_keysign
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - ssh-keysign
- Perform remediation of Audit rules for /usr/lib/ssh/ssh-keysign
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/lib/ssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/lib/ssh/ssh-keysign -F
perm=x -F auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/lib/ssh/ssh-keysign
-F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/lib/ssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
-S |,)\w+)+)( -F path=/usr/lib/ssh/ssh-keysign -F perm=x -F auid>=1000 -F
auid!=unset (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/lib/ssh/ssh-keysign
-F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85582-5
- DISA-STIG-SLES-15-030060
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- audit_rules_privileged_commands_ssh_keysign
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure auditd Collects Information on the Use of Privileged Commands - usermod
[ref]rule
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add a line of the
following form to /etc/audit/audit.rules:
-a always,exit -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged Rationale:Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised system accounts,
is a serious and ongoing concern and can have significant adverse impacts on organizations.
Auditing the use of privileged functions is one way to detect such misuse and identify
the risk from insider and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks,
which attempt to subvert their normal role of providing some necessary but
limited capability. As such, motivation exists to monitor these programs for
unusual activity. Identifiers:
CCE-85600-5 References:
SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SLES-15-030500, SLES-15-750450390, SV-234949r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Retrieve hardware architecture of the underlying system
OTHER_FILTERS="-F path=/usr/sbin/usermod -F perm=x"
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL=""
KEY="privileged"
SYSCALL_GROUPING=""
ACTION_ARCH_FILTERS="-a always,exit"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85600-5
- DISA-STIG-SLES-15-030500
- audit_rules_privileged_commands_usermod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects Information on the Use of Privileged Commands - usermod
- Perform remediation of Audit rules for /usr/sbin/usermod
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/sbin/usermod -F perm=x
-F auid>=1000 -F auid!=unset (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/sbin/usermod -F
perm=x -F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls: []
syscall_grouping: []
- name: Check existence of in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
-S |,)\w+)+)( -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset
(?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/sbin/usermod -F
perm=x -F auid>=1000 -F auid!=unset -F key=privileged
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85600-5
- DISA-STIG-SLES-15-030500
- audit_rules_privileged_commands_usermod
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Records Events that Modify Date and Time Information
[ref]groupArbitrary changes to the system time can be used to obfuscate
nefarious activities in log files, as well as to confuse network services that
are highly dependent upon an accurate system time. All changes to the system
time should be audited. |
| contains 4 rules |
Record attempts to alter time through adjtimex
[ref]ruleIf the auditd daemon is configured to use the
augenrules program to read audit rules during daemon startup (the
default), add the following line to a file with suffix .rules in the
directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S adjtimex -F key=audit_time_rules
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S adjtimex -F key=audit_time_rules
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S adjtimex -F key=audit_time_rules
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S adjtimex -F key=audit_time_rules
The -k option allows for the specification of a key in string form that can be
used for better reporting capability through ausearch and aureport. Multiple
system calls can be defined on the same line to save space if desired, but is
not required. See an example of multiple combined syscalls:
-a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules Rationale:Arbitrary changes to the system time can be used to obfuscate
nefarious activities in log files, as well as to confuse network services that
are highly dependent upon an accurate system time (such as sshd). All changes
to the system time should be audited. Identifiers:
CCE-85814-2 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.4.2.b, 4.1.3, R73, SLES-15-750450180, 0582, 10.6.3, 10.6 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
# Create expected audit group and audit rule form for particular system call & architecture
if [ ${ARCH} = "b32" ]
then
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
# stime system call is known at 32-bit arch (see e.g "$ ausyscall i386 stime" 's output)
# so append it to the list of time group system calls to be audited
SYSCALL="adjtimex settimeofday stime"
SYSCALL_GROUPING="adjtimex settimeofday stime"
elif [ ${ARCH} = "b64" ]
then
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
# stime system call isn't known at 64-bit arch (see "$ ausyscall x86_64 stime" 's output)
# therefore don't add it to the list of time group system calls to be audited
SYSCALL="adjtimex settimeofday"
SYSCALL_GROUPING="adjtimex settimeofday"
fi
OTHER_FILTERS=""
AUID_FILTERS=""
KEY="audit_time_rules"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85814-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_adjtimex
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Set architecture for audit tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85814-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_adjtimex
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Perform remediation of Audit rules for adjtimex for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- adjtimex
syscall_grouping:
- adjtimex
- settimeofday
- stime
- name: Check existence of adjtimex in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- adjtimex
syscall_grouping:
- adjtimex
- settimeofday
- stime
- name: Check existence of adjtimex in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85814-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_adjtimex
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Perform remediation of Audit rules for adjtimex for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- adjtimex
syscall_grouping:
- adjtimex
- settimeofday
- name: Check existence of adjtimex in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_time_rules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- adjtimex
syscall_grouping:
- adjtimex
- settimeofday
- stime
- name: Check existence of adjtimex in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_time_rules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85814-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_adjtimex
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record attempts to alter time through settimeofday
[ref]ruleIf the auditd daemon is configured to use the
augenrules program to read audit rules during daemon startup (the
default), add the following line to a file with suffix .rules in the
directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S settimeofday -F key=audit_time_rules
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S settimeofday -F key=audit_time_rules
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S settimeofday -F key=audit_time_rules
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S settimeofday -F key=audit_time_rules
The -k option allows for the specification of a key in string form that can be
used for better reporting capability through ausearch and aureport. Multiple
system calls can be defined on the same line to save space if desired, but is
not required. See an example of multiple combined syscalls:
-a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules Rationale:Arbitrary changes to the system time can be used to obfuscate
nefarious activities in log files, as well as to confuse network services that
are highly dependent upon an accurate system time (such as sshd). All changes
to the system time should be audited. Identifiers:
CCE-85813-4 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.4.2.b, 4.1.3, SLES-15-750450180, 0582, 10.6.3, 10.6 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
# Create expected audit group and audit rule form for particular system call & architecture
if [ ${ARCH} = "b32" ]
then
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
# stime system call is known at 32-bit arch (see e.g "$ ausyscall i386 stime" 's output)
# so append it to the list of time group system calls to be audited
SYSCALL="adjtimex settimeofday stime"
SYSCALL_GROUPING="adjtimex settimeofday stime"
elif [ ${ARCH} = "b64" ]
then
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
# stime system call isn't known at 64-bit arch (see "$ ausyscall x86_64 stime" 's output)
# therefore don't add it to the list of time group system calls to be audited
SYSCALL="adjtimex settimeofday"
SYSCALL_GROUPING="adjtimex settimeofday"
fi
OTHER_FILTERS=""
AUID_FILTERS=""
KEY="audit_time_rules"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85813-4
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_settimeofday
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Set architecture for audit tasks
set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85813-4
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_settimeofday
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Perform remediation of Audit rules for settimeofday for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- settimeofday
syscall_grouping:
- adjtimex
- settimeofday
- stime
- name: Check existence of settimeofday in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- settimeofday
syscall_grouping:
- adjtimex
- settimeofday
- stime
- name: Check existence of settimeofday in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85813-4
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_settimeofday
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Perform remediation of Audit rules for settimeofday for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- settimeofday
syscall_grouping:
- adjtimex
- settimeofday
- stime
- name: Check existence of settimeofday in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_time_rules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- settimeofday
syscall_grouping:
- adjtimex
- settimeofday
- stime
- name: Check existence of settimeofday in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_time_rules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85813-4
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_settimeofday
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Attempts to Alter Time Through stime
[ref]ruleIf the auditd daemon is configured to use the
augenrules program to read audit rules during daemon startup (the
default), add the following line to a file with suffix .rules in the
directory /etc/audit/rules.d for both 32 bit and 64 bit systems:
-a always,exit -F arch=b32 -S stime -F key=audit_time_rules
Since the 64 bit version of the "stime" system call is not defined in the audit
lookup table, the corresponding "-F arch=b64" form of this rule is not expected
to be defined on 64 bit systems (the aforementioned "-F arch=b32" stime rule
form itself is sufficient for both 32 bit and 64 bit systems). If the
auditd daemon is configured to use the auditctl utility to
read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file for both 32 bit and 64 bit systems:
-a always,exit -F arch=b32 -S stime -F key=audit_time_rules
Since the 64 bit version of the "stime" system call is not defined in the audit
lookup table, the corresponding "-F arch=b64" form of this rule is not expected
to be defined on 64 bit systems (the aforementioned "-F arch=b32" stime rule
form itself is sufficient for both 32 bit and 64 bit systems). The -k option
allows for the specification of a key in string form that can be used for
better reporting capability through ausearch and aureport. Multiple system
calls can be defined on the same line to save space if desired, but is not
required. See an example of multiple combined system calls:
-a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules Rationale:Arbitrary changes to the system time can be used to obfuscate
nefarious activities in log files, as well as to confuse network services that
are highly dependent upon an accurate system time (such as sshd). All changes
to the system time should be audited. Identifiers:
CCE-85815-9 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.4.2.b, 4.1.3, R73, SLES-15-750450180, 0582, 10.6.3, 10.6 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { ( ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ) && ! ( ( grep -sqE "^.*\.s390x$" /proc/sys/kernel/osrelease || grep -sqE "^s390x$" /proc/sys/kernel/arch; ) ) ); }; then
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
# Create expected audit group and audit rule form for particular system call & architecture
if [ ${ARCH} = "b32" ]
then
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
# stime system call is known at 32-bit arch (see e.g "$ ausyscall i386 stime" 's output)
# so append it to the list of time group system calls to be audited
SYSCALL="adjtimex settimeofday stime"
SYSCALL_GROUPING="adjtimex settimeofday stime"
elif [ ${ARCH} = "b64" ]
then
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
# stime system call isn't known at 64-bit arch (see "$ ausyscall x86_64 stime" 's output)
# therefore don't add it to the list of time group system calls to be audited
SYSCALL="adjtimex settimeofday"
SYSCALL_GROUPING="adjtimex settimeofday"
fi
OTHER_FILTERS=""
AUID_FILTERS=""
KEY="audit_time_rules"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85815-9
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_stime
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Perform remediation of Audit rules for stime syscall for x86 platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- stime
syscall_grouping:
- adjtimex
- settimeofday
- stime
- name: Check existence of stime in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- stime
syscall_grouping:
- adjtimex
- settimeofday
- stime
- name: Check existence of stime in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ( not ( ansible_architecture == "aarch64" ) and not ( ansible_architecture ==
"s390x" ) )
tags:
- CCE-85815-9
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_stime
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Attempts to Alter the localtime File
[ref]rule
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /etc/localtime -p wa -k audit_time_rules
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules:
-w /etc/localtime -p wa -k audit_time_rules Rationale:Arbitrary changes to the system time can be used to obfuscate
nefarious activities in log files, as well as to confuse network services that
are highly dependent upon an accurate system time (such as sshd). All changes
to the system time should be audited. Identifiers:
CCE-85812-6 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.4.2.b, 4.1.3, R73, SLES-15-750450180, 0582, 10.6.3, 10.6 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/localtime" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/localtime $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/localtime$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/localtime -p wa -k audit_time_rules" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_time_rules.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/localtime" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/audit_time_rules.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/audit_time_rules.rules"
# If the audit_time_rules.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/localtime" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/localtime $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/localtime$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/localtime -p wa -k audit_time_rules" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85812-6
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_watch_localtime
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter the localtime File - Check if watch rule for /etc/localtime
already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/localtime\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85812-6
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_watch_localtime
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter the localtime File - Search /etc/audit/rules.d for
other rules with specified key audit_time_rules
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_time_rules$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85812-6
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_watch_localtime
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter the localtime File - Use /etc/audit/rules.d/audit_time_rules.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/audit_time_rules.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85812-6
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_watch_localtime
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter the localtime File - Use matched file as the recipient
for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85812-6
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_watch_localtime
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter the localtime File - Add watch rule for /etc/localtime
in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /etc/localtime -p wa -k audit_time_rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85812-6
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_watch_localtime
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter the localtime File - Check if watch rule for /etc/localtime
already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/etc/localtime\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85812-6
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_watch_localtime
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter the localtime File - Add watch rule for /etc/localtime
in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/localtime -p wa -k audit_time_rules
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85812-6
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.4.2.b
- PCI-DSSv4-10.6
- PCI-DSSv4-10.6.3
- audit_rules_time_watch_localtime
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Remove Default Configuration to Disable Syscall Auditing
[ref]ruleBy default, SUSE Linux Enterprise 15 ships an audit rule to disable syscall
auditing for performance reasons.
To make sure that syscall auditing works, this line must be removed from
/etc/audit/rules.d/audit.rules and /etc/audit/audit.rules:
-a task,never Rationale:Audit rules for syscalls do not take effect unless this line is removed. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if [ -f "/usr/lib/systemd/system/auditd.service" ] ; then
IS_AUGENRULES=$(grep -E "^(ExecStartPost=|Requires=augenrules\.service)" /usr/lib/systemd/system/auditd.service)
if [[ "$IS_AUGENRULES" == *"augenrules"* ]] ; then
for f in /etc/audit/rules.d/*.rules ; do
sed -E -i --follow-symlinks 's/^(\s*-a\s+task,never)/#\1/' "$f"
done
else
# auditctl is used
sed -E -i --follow-symlinks 's/^(\s*-a\s+task,never)/#\1/' /etc/audit/audit.rules
fi
systemctl is-active --quiet auditd.service
if [ $? -ne 0 ] ; then
systemctl restart auditd.service
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85706-0
- DISA-STIG-SLES-15-030820
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- audit_rules_enable_syscall_auditing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Service facts
ansible.builtin.service_facts: null
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85706-0
- DISA-STIG-SLES-15-030820
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- audit_rules_enable_syscall_auditing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check if auditctl rules script being used
ansible.builtin.find:
paths: /usr/lib/systemd/system/
patterns: auditd.service
contains: ^\s*(ExecStartPost|Requires)\s*=[\s\-]*[\w\/]*auditctl
register: auditd_svc_auditctl_used
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85706-0
- DISA-STIG-SLES-15-030820
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- audit_rules_enable_syscall_auditing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Check augenrules rules script being used
ansible.builtin.find:
paths: /usr/lib/systemd/system/
patterns: auditd.service
contains: ^\s*(ExecStartPost|Requires)\s*=[\s\-]*[\w\/]*augenrules
register: auditd_svc_augen_used
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85706-0
- DISA-STIG-SLES-15-030820
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- audit_rules_enable_syscall_auditing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Find audit rules in /etc/audit/rules.d
ansible.builtin.find:
paths: /etc/audit/rules.d
file_type: file
follow: true
register: find_audit_rules_result
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"auditd.service" in ansible_facts.services'
- auditd_svc_augen_used is defined and auditd_svc_augen_used.matched >= 1
tags:
- CCE-85706-0
- DISA-STIG-SLES-15-030820
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- audit_rules_enable_syscall_auditing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Enable syscall auditing (augenrules)
ansible.builtin.lineinfile:
path: '{{ item.path }}'
regex: (?i)^(\s*-a\s+task,never)\s*$
line: '#-a task,never'
with_items: '{{ find_audit_rules_result.files }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"auditd.service" in ansible_facts.services'
- auditd_svc_augen_used is defined and auditd_svc_augen_used.matched >= 1
register: augenrules_syscall_auditing_rule_update_result
tags:
- CCE-85706-0
- DISA-STIG-SLES-15-030820
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- audit_rules_enable_syscall_auditing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Enable syscall auditing (auditctl)
ansible.builtin.lineinfile:
path: /etc/audit/audit.rules
regex: (?i)^(\s*-a\s+task,never)\s*$
line: '#-a task,never'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"auditd.service" in ansible_facts.services'
- auditd_svc_auditctl_used is defined and auditd_svc_auditctl_used.matched >= 1
register: auditctl_syscall_auditing_rule_update_result
tags:
- CCE-85706-0
- DISA-STIG-SLES-15-030820
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- audit_rules_enable_syscall_auditing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Restart auditd.service
ansible.builtin.systemd:
name: auditd.service
state: restarted
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_facts.services["auditd.service"].state == "running"
- (augenrules_syscall_auditing_rule_update_result.changed or auditctl_syscall_auditing_rule_update_result.changed)
tags:
- CCE-85706-0
- DISA-STIG-SLES-15-030820
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- audit_rules_enable_syscall_auditing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Make the auditd Configuration Immutable
[ref]ruleIf the auditd daemon is configured to use the
augenrules program to read audit rules during daemon startup (the
default), add the following line to a file with suffix .rules in the
directory /etc/audit/rules.d in order to make the auditd configuration
immutable:
-e 2
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file in order to make the auditd configuration
immutable:
-e 2
With this setting, a reboot will be required to change any audit rules.Rationale:Making the audit configuration immutable prevents accidental as
well as malicious modification of the audit rules, although it may be
problematic if legitimate changes are needed during system
operation. Identifiers:
CCE-85831-6 References:
1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO01.06, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.3.1, 3.4.3, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.310(a)(2)(iv), 164.312(d), 164.310(d)(2)(iii), 164.312(b), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, ID.SC-4, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.5.2, SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-APP-000119-CTR-000245, SRG-APP-000120-CTR-000250, 4.1.17, R73, SLES-15-750450420, 10.3.2, 10.3 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Traverse all of:
#
# /etc/audit/audit.rules, (for auditctl case)
# /etc/audit/rules.d/*.rules (for augenrules case)
#
# files to check if '-e .*' setting is present in that '*.rules' file already.
# If found, delete such occurrence since auditctl(8) manual page instructs the
# '-e 2' rule should be placed as the last rule in the configuration
find /etc/audit /etc/audit/rules.d -maxdepth 1 -type f -name '*.rules' -exec sed -i '/-e[[:space:]]\+.*/d' {} ';'
# Append '-e 2' requirement at the end of both:
# * /etc/audit/audit.rules file (for auditctl case)
# * /etc/audit/rules.d/immutable.rules (for augenrules case)
for AUDIT_FILE in "/etc/audit/audit.rules" "/etc/audit/rules.d/immutable.rules"
do
echo '' >> $AUDIT_FILE
echo '# Set the audit.rules configuration immutable per security requirements' >> $AUDIT_FILE
echo '# Reboot is required to change audit rules once this setting is applied' >> $AUDIT_FILE
echo '-e 2' >> $AUDIT_FILE
chmod o-rwx $AUDIT_FILE
chmod g-rwx $AUDIT_FILE
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85831-6
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-171-3.4.3
- NIST-800-53-AC-6(9)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- audit_rules_immutable
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Make the auditd Configuration Immutable - Collect all files from /etc/audit/rules.d
with .rules extension
ansible.builtin.find:
paths: /etc/audit/rules.d/
patterns: '*.rules'
register: find_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85831-6
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-171-3.4.3
- NIST-800-53-AC-6(9)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- audit_rules_immutable
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Make the auditd Configuration Immutable - Check if target files exist and
get their content
ansible.builtin.stat:
path: '{{ item }}'
register: audit_files_stat
loop:
- /etc/audit/audit.rules
- /etc/audit/rules.d/immutable.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85831-6
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-171-3.4.3
- NIST-800-53-AC-6(9)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- audit_rules_immutable
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Make the auditd Configuration Immutable - Read content of existing audit files
ansible.builtin.slurp:
src: '{{ item.item }}'
register: audit_files_content
loop: '{{ audit_files_stat.results }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- item.stat.exists
tags:
- CCE-85831-6
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-171-3.4.3
- NIST-800-53-AC-6(9)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- audit_rules_immutable
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Make the auditd Configuration Immutable - Check if -e 2 is already correctly
set in target files
ansible.builtin.set_fact:
immutable_correctly_set: |-
{{
audit_files_content.results
| selectattr('content', 'defined')
| map(attribute='content')
| map('b64decode')
| select('search', '^-e 2$', multiline=True)
| list
| length == 2
}}
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85831-6
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-171-3.4.3
- NIST-800-53-AC-6(9)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- audit_rules_immutable
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Make the auditd Configuration Immutable - Remove any existing -e option from
all Audit config files
ansible.builtin.lineinfile:
path: '{{ item }}'
regexp: ^\s*-e\s+.*$
state: absent
loop: '{{ find_rules_d.files | map(attribute=''path'') | list + [''/etc/audit/audit.rules'']
}}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not immutable_correctly_set
tags:
- CCE-85831-6
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-171-3.4.3
- NIST-800-53-AC-6(9)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- audit_rules_immutable
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Make the auditd Configuration Immutable - Ensure target directories exist
ansible.builtin.file:
path: '{{ item | dirname }}'
state: directory
mode: '0750'
loop:
- /etc/audit/audit.rules
- /etc/audit/rules.d/immutable.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not immutable_correctly_set
tags:
- CCE-85831-6
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-171-3.4.3
- NIST-800-53-AC-6(9)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- audit_rules_immutable
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Make the auditd Configuration Immutable - Add Audit -e 2 option to make rules
immutable
ansible.builtin.lineinfile:
path: '{{ item }}'
create: true
line: -e 2
regexp: ^\s*-e\s+.*$
mode: g-rwx,o-rwx
loop:
- /etc/audit/audit.rules
- /etc/audit/rules.d/immutable.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- not immutable_correctly_set
tags:
- CCE-85831-6
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-171-3.4.3
- NIST-800-53-AC-6(9)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- audit_rules_immutable
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Mandatory Access Controls
[ref]ruleIf the auditd daemon is configured to use the
augenrules program to read audit rules during daemon startup (the
default), add the following line to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /etc/selinux/ -p wa -k MAC-policy
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file:
-w /etc/selinux/ -p wa -k MAC-policy Rationale:The system's mandatory access policy (SELinux or Apparmor) should not be
arbitrarily changed by anything other than administrator action. All changes to
MAC policy should be audited. Identifiers:
CCE-85830-8 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.8, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, 4.1.6, R73, SLES-15-750450330, 10.3.4, 10.3 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/selinux/" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/selinux/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/selinux/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/selinux/ -p wa -k MAC-policy" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/MAC-policy.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/selinux/" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/MAC-policy.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/MAC-policy.rules"
# If the MAC-policy.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/selinux/" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/selinux/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/selinux/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/selinux/ -p wa -k MAC-policy" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85830-8
- CJIS-5.4.1.1
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_mac_modification
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls - Check if
watch rule for /etc/selinux/ already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/selinux/\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85830-8
- CJIS-5.4.1.1
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_mac_modification
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls - Search
/etc/audit/rules.d for other rules with specified key MAC-policy
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)MAC-policy$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85830-8
- CJIS-5.4.1.1
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_mac_modification
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls - Use /etc/audit/rules.d/MAC-policy.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/MAC-policy.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85830-8
- CJIS-5.4.1.1
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_mac_modification
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls - Use matched
file as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85830-8
- CJIS-5.4.1.1
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_mac_modification
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls - Add watch
rule for /etc/selinux/ in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /etc/selinux/ -p wa -k MAC-policy
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85830-8
- CJIS-5.4.1.1
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_mac_modification
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls - Check if
watch rule for /etc/selinux/ already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/etc/selinux/\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85830-8
- CJIS-5.4.1.1
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_mac_modification
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls - Add watch
rule for /etc/selinux/ in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/selinux/ -p wa -k MAC-policy
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85830-8
- CJIS-5.4.1.1
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_mac_modification
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Mandatory Access Controls in usr/share
[ref]rule
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /usr/share/selinux/ -p wa -k MAC-policy
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules:
-w /usr/share/selinux/ -p wa -k MAC-policy Rationale:The system's mandatory access policy (SELinux) should not be
arbitrarily changed by anything other than administrator action. All changes to
MAC policy should be audited. Identifiers:
CCE-92515-6 References:
APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.8, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, 4.1.6, SLES-15-750450330 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/usr/share/selinux/" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/usr/share/selinux/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/usr/share/selinux/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /usr/share/selinux/ -p wa -k MAC-policy" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/MAC-policy.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/usr/share/selinux/" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/MAC-policy.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/MAC-policy.rules"
# If the MAC-policy.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/usr/share/selinux/" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/usr/share/selinux/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/usr/share/selinux/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /usr/share/selinux/ -p wa -k MAC-policy" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92515-6
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- audit_rules_mac_modification_usr_share
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls in usr/share
- Check if watch rule for /usr/share/selinux/ already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/usr/share/selinux/\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92515-6
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- audit_rules_mac_modification_usr_share
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls in usr/share
- Search /etc/audit/rules.d for other rules with specified key MAC-policy
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)MAC-policy$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-92515-6
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- audit_rules_mac_modification_usr_share
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls in usr/share
- Use /etc/audit/rules.d/MAC-policy.rules as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/MAC-policy.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-92515-6
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- audit_rules_mac_modification_usr_share
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls in usr/share
- Use matched file as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-92515-6
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- audit_rules_mac_modification_usr_share
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls in usr/share
- Add watch rule for /usr/share/selinux/ in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /usr/share/selinux/ -p wa -k MAC-policy
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-92515-6
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- audit_rules_mac_modification_usr_share
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls in usr/share
- Check if watch rule for /usr/share/selinux/ already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/usr/share/selinux/\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92515-6
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- audit_rules_mac_modification_usr_share
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls in usr/share
- Add watch rule for /usr/share/selinux/ in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /usr/share/selinux/ -p wa -k MAC-policy
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-92515-6
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- audit_rules_mac_modification_usr_share
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Ensure auditd Collects Information on Exporting to Media (successful)
[ref]ruleAt a minimum, the audit system should collect media exportation
events for all users and root. If the auditd daemon is configured to
use the augenrules program to read audit rules during daemon startup
(the default), add the following line to a file with suffix .rules in
the directory /etc/audit/rules.d, setting ARCH to either b32 for
32-bit system, or having two lines for both b32 and b64 in case your
system is 64-bit:
-a always,exit -F arch=ARCH -S mount -F auid>=1000 -F auid!=unset -F key=export
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following line to
/etc/audit/audit.rules file, setting ARCH to either b32 for
32-bit system, or having two lines for both b32 and b64 in case your
system is 64-bit:
-a always,exit -F arch=ARCH -S mount -F auid>=1000 -F auid!=unset -F key=export Rationale:The unauthorized exportation of data to external media could result in an information leak
where classified information, Privacy Act information, and intellectual property could be lost. An audit
trail should be created each time a filesystem is mounted to help identify and guard against information
loss. Identifiers:
CCE-85718-5 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.7, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-APP-000495-CTR-001235, SLES-15-030350, 4.1.12, R73, SLES-15-750450270, 10.2.1.7, 10.2.1, 10.2, SV-234934r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS="-F auid>=1000 -F auid!=unset"
SYSCALL="mount"
KEY="export"
SYSCALL_GROUPING=""
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85718-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030350
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_media_export
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Set architecture for audit mount tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85718-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030350
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_media_export
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for mount for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- mount
syscall_grouping: []
- name: Check existence of mount in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/export.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/export.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=export
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- mount
syscall_grouping: []
- name: Check existence of mount in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=export
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85718-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030350
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_media_export
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Perform remediation of Audit rules for mount for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- mount
syscall_grouping: []
- name: Check existence of mount in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/export.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/export.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
|-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=export
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- mount
syscall_grouping: []
- name: Check existence of mount in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
-F auid!=unset -F key=export
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85718-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030350
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.7
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.7
- audit_rules_media_export
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events that Modify the System's Network Environment
[ref]ruleIf the auditd daemon is configured to use the
augenrules program to read audit rules during daemon startup (the
default), add the following lines to a file with suffix .rules in the
directory /etc/audit/rules.d, setting ARCH to either b32 for
32-bit system, or having two lines for both b32 and b64 in case your system
is 64-bit:
-a always,exit -F arch=ARCH -S sethostname,setdomainname -F key=audit_rules_networkconfig_modification
-w /etc/issue -p wa -k audit_rules_networkconfig_modification
-w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
-w /etc/hosts -p wa -k audit_rules_networkconfig_modification
-w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules file, setting ARCH to either b32 for
32-bit system, or having two lines for both b32 and b64 in case your system
is 64-bit:
-a always,exit -F arch=ARCH -S sethostname,setdomainname -F key=audit_rules_networkconfig_modification
-w /etc/issue -p wa -k audit_rules_networkconfig_modification
-w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
-w /etc/hosts -p wa -k audit_rules_networkconfig_modification
-w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification Rationale:The network environment should not be modified by anything other
than administrator action. Any change to network parameters should be
audited. Identifiers:
CCE-85828-2 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.5.5, 4.1.5, R73, SLES-15-750450195, 0582, 10.3.4, 10.3 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# First perform the remediation of the syscall rule
# Retrieve hardware architecture of the underlying system
[ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")
for ARCH in "${RULE_ARCHS[@]}"
do
ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
OTHER_FILTERS=""
AUID_FILTERS=""
SYSCALL="sethostname setdomainname"
KEY="audit_rules_networkconfig_modification"
SYSCALL_GROUPING="sethostname setdomainname"
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'augenrules', then check if the audit rule is defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
# If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
default_file="/etc/audit/rules.d/$KEY.rules"
# As other_filters may include paths, lets use a different delimiter for it
# The "F" script expression tells sed to print the filenames where the expressions matched
readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
# Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
if [ ${#files_to_inspect[@]} -eq "0" ]
then
file_to_inspect="/etc/audit/rules.d/$KEY.rules"
files_to_inspect=("$file_to_inspect")
if [ ! -e "$file_to_inspect" ]
then
touch "$file_to_inspect"
chmod 0600 "$file_to_inspect"
fi
fi
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
unset syscall_a
unset syscall_grouping
unset syscall_string
unset syscall
unset file_to_edit
unset rule_to_edit
unset rule_syscalls_to_edit
unset other_string
unset auid_string
unset full_rule
# Load macro arguments into arrays
read -a syscall_a <<< $SYSCALL
read -a syscall_grouping <<< $SYSCALL_GROUPING
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
#
files_to_inspect=()
# If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# file to the list of files to be inspected
default_file="/etc/audit/audit.rules"
files_to_inspect+=('/etc/audit/audit.rules' )
# After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
skip=1
for audit_file in "${files_to_inspect[@]}"
do
# Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
# i.e, collect rules that match:
# * the action, list and arch, (2-nd argument)
# * the other filters, (3-rd argument)
# * the auid filters, (4-rd argument)
readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")
candidate_rules=()
# Filter out rules that have more fields then required. This will remove rules more specific than the required scope
for s_rule in "${similar_rules[@]}"
do
# Strip all the options and fields we know of,
# than check if there was any field left over
extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//" -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
done
if [[ ${#syscall_a[@]} -ge 1 ]]
then
# Check if the syscall we want is present in any of the similar existing rules
for rule in "${candidate_rules[@]}"
do
rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
all_syscalls_found=0
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
# A syscall was not found in the candidate rule
all_syscalls_found=1
}
done
if [[ $all_syscalls_found -eq 0 ]]
then
# We found a rule with all the syscall(s) we want; skip rest of macro
skip=0
break
fi
# Check if this rule can be grouped with our target syscall and keep track of it
for syscall_g in "${syscall_grouping[@]}"
do
if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
then
file_to_edit=${audit_file}
rule_to_edit=${rule}
rule_syscalls_to_edit=${rule_syscalls}
fi
done
done
else
# If there is any candidate rule, it is compliant; skip rest of macro
if [ "${#candidate_rules[@]}" -gt 0 ]
then
skip=0
fi
fi
if [ "$skip" -eq 0 ]; then
break
fi
done
if [ "$skip" -ne 0 ]; then
# We checked all rules that matched the expected resemblance pattern (action, arch & auid)
# At this point we know if we need to either append the $full_rule or group
# the syscall together with an exsiting rule
# Append the full_rule if it cannot be grouped to any other rule
if [ -z ${rule_to_edit+x} ]
then
# Build full_rule while avoid adding double spaces when other_filters is empty
if [ "${#syscall_a[@]}" -gt 0 ]
then
syscall_string=""
for syscall in "${syscall_a[@]}"
do
syscall_string+=" -S $syscall"
done
fi
other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
echo "$full_rule" >> "$default_file"
chmod 0600 ${default_file}
else
# Check if the syscalls are declared as a comma separated list or
# as multiple -S parameters
if grep -q -- "," <<< "${rule_syscalls_to_edit}"
then
delimiter=","
else
delimiter=" -S "
fi
new_grouped_syscalls="${rule_syscalls_to_edit}"
for syscall in "${syscall_a[@]}"
do
grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
# A syscall was not found in the candidate rule
new_grouped_syscalls+="${delimiter}${syscall}"
}
done
# Group the syscall in the rule
sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
fi
fi
done
# Then perform the remediations for the watch rules
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/issue" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/issue $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/issue$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/issue -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/issue" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
# If the audit_rules_networkconfig_modification.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/issue" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/issue $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/issue$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/issue -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/issue.net" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/issue.net $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/issue.net$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/issue.net -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/issue.net" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
# If the audit_rules_networkconfig_modification.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/issue.net" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/issue.net $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/issue.net$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/issue.net -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/hosts" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/hosts $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/hosts$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/hosts -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/hosts" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
# If the audit_rules_networkconfig_modification.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/hosts" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/hosts $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/hosts$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/hosts -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/sysconfig/network" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sysconfig/network $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/sysconfig/network$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/sysconfig/network" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
# If the audit_rules_networkconfig_modification.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/sysconfig/network" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sysconfig/network $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/sysconfig/network$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Set architecture for audit tasks
ansible.builtin.set_fact:
audit_arch: b64
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
== "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Remediate audit rules for network configuration for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- sethostname
- setdomainname
syscall_grouping:
- sethostname
- setdomainname
- name: Check existence of sethostname, setdomainname in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_rules_networkconfig_modification
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- sethostname
- setdomainname
syscall_grouping:
- sethostname
- setdomainname
- name: Check existence of sethostname, setdomainname in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_rules_networkconfig_modification
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Remediate audit rules for network configuration for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- sethostname
- setdomainname
syscall_grouping:
- sethostname
- setdomainname
- name: Check existence of sethostname, setdomainname in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: '*.rules'
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Reset syscalls found per file
ansible.builtin.set_fact:
syscalls_per_file: {}
found_paths_dict: {}
- name: Declare syscalls found per file
ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
:[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
loop: '{{ find_command.results | selectattr(''matched'') | list }}'
- name: Declare files where syscalls were found
ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
| flatten | map(attribute='path') | list }}"
- name: Count occurrences of syscalls in paths
ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
0) }) }}"
loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
| list }}'
- name: Get path with most syscalls
ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
| last).key }}"
when: found_paths | length >= 1
- name: No file with syscall found, set path to /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
when: found_paths | length == 0
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
| join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_rules_networkconfig_modification
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- sethostname
- setdomainname
syscall_grouping:
- sethostname
- setdomainname
- name: Check existence of sethostname, setdomainname in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit
contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
|,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
patterns: audit.rules
register: find_command
loop: '{{ (syscall_grouping + syscalls) | unique }}'
- name: Set path to /etc/audit/audit.rules
ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"
- name: Declare found syscalls
ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
| map(attribute='item') | list }}"
- name: Declare missing syscalls
ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
}}"
- name: Replace the audit rule in {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
line: \1\2\3{{ missing_syscalls | join("\3") }}\4
backrefs: true
state: present
mode: g-rwx,o-rwx
when: syscalls_found | length > 0 and missing_syscalls | length > 0
- name: Add the audit rule to {{ audit_file }}
ansible.builtin.lineinfile:
path: '{{ audit_file }}'
line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_rules_networkconfig_modification
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- audit_arch == "b64"
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Check if watch
rule for /etc/issue already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/issue\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Search /etc/audit/rules.d
for other rules with specified key audit_rules_networkconfig_modification
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_rules_networkconfig_modification$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Use /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Use matched file
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Add watch rule
for /etc/issue in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /etc/issue -p wa -k audit_rules_networkconfig_modification
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Check if watch
rule for /etc/issue already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/etc/issue\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Add watch rule
for /etc/issue in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/issue -p wa -k audit_rules_networkconfig_modification
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Check if watch
rule for /etc/issue.net already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/issue.net\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Search /etc/audit/rules.d
for other rules with specified key audit_rules_networkconfig_modification
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_rules_networkconfig_modification$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Use /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Use matched file
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Add watch rule
for /etc/issue.net in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Check if watch
rule for /etc/issue.net already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/etc/issue.net\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Add watch rule
for /etc/issue.net in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Check if watch
rule for /etc/hosts already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/hosts\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Search /etc/audit/rules.d
for other rules with specified key audit_rules_networkconfig_modification
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_rules_networkconfig_modification$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Use /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Use matched file
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Add watch rule
for /etc/hosts in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /etc/hosts -p wa -k audit_rules_networkconfig_modification
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Check if watch
rule for /etc/hosts already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/etc/hosts\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Add watch rule
for /etc/hosts in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/hosts -p wa -k audit_rules_networkconfig_modification
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Check if watch
rule for /etc/sysconfig/network already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/sysconfig/network\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Search /etc/audit/rules.d
for other rules with specified key audit_rules_networkconfig_modification
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_rules_networkconfig_modification$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Use /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Use matched file
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Add watch rule
for /etc/sysconfig/network in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Check if watch
rule for /etc/sysconfig/network already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/etc/sysconfig/network\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Network Environment - Add watch rule
for /etc/sysconfig/network in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85828-2
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.4
- audit_rules_networkconfig_modification
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Attempts to Alter Process and Session Initiation Information
[ref]ruleThe audit system already collects process information for all
users and root. If the auditd daemon is configured to use the
augenrules program to read audit rules during daemon startup (the
default), add the following lines to a file with suffix .rules in the
directory /etc/audit/rules.d in order to watch for attempted manual
edits of files involved in storing such process information:
-w /var/run/utmp -p wa -k session
-w /var/log/btmp -p wa -k session
-w /var/log/wtmp -p wa -k session
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules file in order to watch for attempted manual
edits of files involved in storing such process information:
-w /var/run/utmp -p wa -k session
-w /var/log/btmp -p wa -k session
-w /var/log/wtmp -p wa -k session Rationale:Manual editing of these files may indicate nefarious activity, such
as an attacker attempting to remove evidence of an intrusion. Identifiers:
CCE-85829-0 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AU-2(d), AU-12(c), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.3, SRG-APP-000505-CTR-001285, 4.1.8, SLES-15-750450285 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/var/run/utmp" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/run/utmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/var/run/utmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /var/run/utmp -p wa -k session" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/session.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/run/utmp" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/session.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/session.rules"
# If the session.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/var/run/utmp" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/run/utmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/var/run/utmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /var/run/utmp -p wa -k session" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/var/log/btmp" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/btmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/var/log/btmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /var/log/btmp -p wa -k session" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/session.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/log/btmp" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/session.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/session.rules"
# If the session.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/var/log/btmp" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/btmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/var/log/btmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /var/log/btmp -p wa -k session" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/var/log/wtmp" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/wtmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/var/log/wtmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /var/log/wtmp -p wa -k session" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/session.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/log/wtmp" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/session.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/session.rules"
# If the session.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/var/log/wtmp" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/wtmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/var/log/wtmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /var/log/wtmp -p wa -k session" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Check
if watch rule for /var/run/utmp already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/var/run/utmp\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Search
/etc/audit/rules.d for other rules with specified key session
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)session$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Use
/etc/audit/rules.d/session.rules as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/session.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Use
matched file as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Add
watch rule for /var/run/utmp in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /var/run/utmp -p wa -k session
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Check
if watch rule for /var/run/utmp already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/var/run/utmp\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Add
watch rule for /var/run/utmp in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /var/run/utmp -p wa -k session
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Check
if watch rule for /var/log/btmp already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/var/log/btmp\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Search
/etc/audit/rules.d for other rules with specified key session
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)session$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Use
/etc/audit/rules.d/session.rules as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/session.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Use
matched file as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Add
watch rule for /var/log/btmp in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /var/log/btmp -p wa -k session
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Check
if watch rule for /var/log/btmp already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/var/log/btmp\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Add
watch rule for /var/log/btmp in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /var/log/btmp -p wa -k session
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Check
if watch rule for /var/log/wtmp already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/var/log/wtmp\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Search
/etc/audit/rules.d for other rules with specified key session
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)session$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Use
/etc/audit/rules.d/session.rules as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/session.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Use
matched file as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Add
watch rule for /var/log/wtmp in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /var/log/wtmp -p wa -k session
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Check
if watch rule for /var/log/wtmp already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/var/log/wtmp\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Record Attempts to Alter Process and Session Initiation Information - Add
watch rule for /var/log/wtmp in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /var/log/wtmp -p wa -k session
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85829-0
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- audit_rules_session_events
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
|
Record Events When Executables Are Run As Another User
[ref]ruleVerify the system generates an audit record when actions are run as another user.
sudo provides users with temporary elevated privileges to perform operations, either as the superuser or another user.
If audit is using the "auditctl" tool to load the rules, run the following command:
$ sudo grep execve /etc/audit/audit.rules
If audit is using the "augenrules" tool to load the rules, run the following command:
$ sudo grep -r execve /etc/audit/rules.d
-a always,exit -F arch=b32 -S execve -C euid!=uid -F auid!=unset -k user_emulation
-a always,exit -F arch=b64 S execve -C euid!=uid -F auid!=unset -k user_emulation
If both the "b32" and "b64" audit rules for "SUID" files are not defined, this is a finding.Warning:
Note that these rules can be configured in a
number of ways while still achieving the desired effect. Rationale:Creating an audit log of users with temporary elevated privileges and the
operation(s) they performed is essential to reporting. Administrators will
want to correlate the events written to the audit trail with the records
written to sudo's logfile to verify if unauthorized commands have
been executed.
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have
compromised information system accounts, is a serious and ongoing concern
and can have significant adverse impacts on organizations. Auditing the use
of privileged functions is one way to detect such misuse and identify the
risk from insider threats and the advanced persistent threat. |
Ensure auditd Collects System Administrator Actions
[ref]rule
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /etc/sudoers -p wa -k actions
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules:
-w /etc/sudoers -p wa -k actions
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /etc/sudoers.d/ -p wa -k actions
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules:
-w /etc/sudoers.d/ -p wa -k actions Rationale:The actions taken by system administrators should be audited to keep a record
of what was executed on the system, as well as, for accountability purposes. Identifiers:
CCE-85679-9 References:
1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, AU-3, AU-3.1, AU-12(a), AU-12.1(ii), AU-12.1(iv), MA-4(1)(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.2, Req-10.2.5.b, SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221, SRG-APP-000026-CTR-000070, SRG-APP-000027-CTR-000075, SRG-APP-000028-CTR-000080, SRG-APP-000291-CTR-000675, SRG-APP-000292-CTR-000680, SRG-APP-000293-CTR-000685, SRG-APP-000294-CTR-000690, SRG-APP-000319-CTR-000745, SRG-APP-000320-CTR-000750, SRG-APP-000509-CTR-001305, SLES-15-030140, 4.1.14, R73, SLES-15-750450135, 0582, 10.2.1.5, 10.2.1, 10.2, SV-234913r958412_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/sudoers$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/sudoers -p wa -k actions" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/actions.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/sudoers" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/actions.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/actions.rules"
# If the actions.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/sudoers$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/sudoers -p wa -k actions" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers.d/" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers.d/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/sudoers.d/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/sudoers.d/ -p wa -k actions" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/actions.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/sudoers.d/" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/actions.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/actions.rules"
# If the actions.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers.d/" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers.d/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/sudoers.d/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/sudoers.d/ -p wa -k actions" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Check if watch rule
for /etc/sudoers already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/etc/sudoers\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Add watch rule for /etc/sudoers
in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/sudoers -p wa -k actions
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Check if watch rule
for /etc/sudoers already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/sudoers\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Search /etc/audit/rules.d
for other rules with specified key actions
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)actions$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Use /etc/audit/rules.d/actions.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/actions.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Use matched file as
the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Add watch rule for /etc/sudoers
in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /etc/sudoers -p wa -k actions
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Check if watch rule
for /etc/sudoers.d/ already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/etc/sudoers.d/\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Add watch rule for /etc/sudoers.d/
in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/sudoers.d/ -p wa -k actions
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Check if watch rule
for /etc/sudoers.d/ already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/sudoers.d/\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Search /etc/audit/rules.d
for other rules with specified key actions
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)actions$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Use /etc/audit/rules.d/actions.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/actions.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Use matched file as
the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Add watch rule for /etc/sudoers.d/
in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /etc/sudoers.d/ -p wa -k actions
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85679-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030140
- NIST-800-171-3.1.7
- NIST-800-53-AU-12(a)
- NIST-800-53-AU-12.1(ii)
- NIST-800-53-AU-12.1(iv)
- NIST-800-53-AU-3
- NIST-800-53-AU-3.1
- NIST-800-53-MA-4(1)(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Events that Modify User/Group Information - /etc/group
[ref]rule
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /etc/group -p wa -k audit_rules_usergroup_modification
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules:
-w /etc/group -p wa -k audit_rules_usergroup_modification Rationale:In addition to auditing new user and group accounts, these watches
will alert the system administrator(s) to any modifications. Any unexpected
users, groups, or modifications should be investigated for legitimacy. Identifiers:
CCE-85578-3 References:
1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.5, SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000503-CTR-001275, SLES-15-030010, 4.1.4, R73, SLES-15-750450240, 0582, 10.2.1.5, 10.2.1, 10.2, SV-234900r1009635_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/group" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/group $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/group$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/group -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/group" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
# If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/group" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/group $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/group$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/group -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85578-3
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030010
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/group - Check if watch
rule for /etc/group already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/group\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85578-3
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030010
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/group - Search /etc/audit/rules.d
for other rules with specified key audit_rules_usergroup_modification
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85578-3
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030010
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/group - Use /etc/audit/rules.d/audit_rules_usergroup_modification.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/audit_rules_usergroup_modification.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85578-3
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030010
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/group - Use matched
file as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85578-3
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030010
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/group - Add watch
rule for /etc/group in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /etc/group -p wa -k audit_rules_usergroup_modification
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85578-3
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030010
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/group - Check if watch
rule for /etc/group already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/etc/group\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85578-3
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030010
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/group - Add watch
rule for /etc/group in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/group -p wa -k audit_rules_usergroup_modification
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85578-3
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030010
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Events that Modify User/Group Information - /etc/gshadow
[ref]rule
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /etc/gshadow -p wa -k audit_rules_usergroup_modification
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules:
-w /etc/gshadow -p wa -k audit_rules_usergroup_modification Rationale:In addition to auditing new user and group accounts, these watches
will alert the system administrator(s) to any modifications. Any unexpected
users, groups, or modifications should be investigated for legitimacy. Identifiers:
CCE-85580-9 References:
1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.5, SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000503-CTR-001275, SLES-15-030040, 4.1.4, R73, SLES-15-750450240, 0582, 10.2.1.5, 10.2.1, 10.2, SV-234903r958368_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/gshadow" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/gshadow $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/gshadow$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/gshadow -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/gshadow" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
# If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/gshadow" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/gshadow $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/gshadow$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/gshadow -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85580-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030040
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/gshadow - Check if
watch rule for /etc/gshadow already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/gshadow\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85580-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030040
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/gshadow - Search /etc/audit/rules.d
for other rules with specified key audit_rules_usergroup_modification
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85580-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030040
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/gshadow - Use /etc/audit/rules.d/audit_rules_usergroup_modification.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/audit_rules_usergroup_modification.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85580-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030040
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/gshadow - Use matched
file as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85580-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030040
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/gshadow - Add watch
rule for /etc/gshadow in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /etc/gshadow -p wa -k audit_rules_usergroup_modification
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85580-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030040
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/gshadow - Check if
watch rule for /etc/gshadow already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/etc/gshadow\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85580-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030040
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/gshadow - Add watch
rule for /etc/gshadow in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/gshadow -p wa -k audit_rules_usergroup_modification
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85580-9
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030040
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Events that Modify User/Group Information - /etc/security/opasswd
[ref]rule
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules:
-w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification Rationale:In addition to auditing new user and group accounts, these watches
will alert the system administrator(s) to any modifications. Any unexpected
users, groups, or modifications should be investigated for legitimacy. Identifiers:
CCE-85728-4 References:
1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4).1(i&ii), AU-12.1(iv), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.5, SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221, SRG-APP-000495-CTR-001235, SRG-APP-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000503-CTR-001275, SLES-15-030030, 4.1.4, R73, SLES-15-750450240, 0582, 10.2.1.5, 10.2.1, 10.2, SV-234902r1009637_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/security/opasswd" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/security/opasswd $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/security/opasswd$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/security/opasswd" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
# If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/security/opasswd" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/security/opasswd $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/security/opasswd$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85728-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030030
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4).1(i&ii)
- NIST-800-53-AU-12.1(iv)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/security/opasswd -
Check if watch rule for /etc/security/opasswd already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/security/opasswd\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85728-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030030
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4).1(i&ii)
- NIST-800-53-AU-12.1(iv)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/security/opasswd -
Search /etc/audit/rules.d for other rules with specified key audit_rules_usergroup_modification
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85728-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030030
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4).1(i&ii)
- NIST-800-53-AU-12.1(iv)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/security/opasswd -
Use /etc/audit/rules.d/audit_rules_usergroup_modification.rules as the recipient
for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/audit_rules_usergroup_modification.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85728-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030030
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4).1(i&ii)
- NIST-800-53-AU-12.1(iv)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/security/opasswd -
Use matched file as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85728-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030030
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4).1(i&ii)
- NIST-800-53-AU-12.1(iv)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/security/opasswd -
Add watch rule for /etc/security/opasswd in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85728-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030030
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4).1(i&ii)
- NIST-800-53-AU-12.1(iv)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/security/opasswd -
Check if watch rule for /etc/security/opasswd already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/etc/security/opasswd\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85728-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030030
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4).1(i&ii)
- NIST-800-53-AU-12.1(iv)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/security/opasswd -
Add watch rule for /etc/security/opasswd in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85728-4
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030030
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4).1(i&ii)
- NIST-800-53-AU-12.1(iv)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Events that Modify User/Group Information - /etc/passwd
[ref]rule
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /etc/passwd -p wa -k audit_rules_usergroup_modification
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules:
-w /etc/passwd -p wa -k audit_rules_usergroup_modification Rationale:In addition to auditing new user and group accounts, these watches
will alert the system administrator(s) to any modifications. Any unexpected
users, groups, or modifications should be investigated for legitimacy. Identifiers:
CCE-85577-5 References:
1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.5, SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221, SRG-OS-000274-GPOS-00104, SRG-OS-000275-GPOS-00105, SRG-OS-000276-GPOS-00106, SRG-OS-000277-GPOS-00107, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000503-CTR-001275, SLES-15-030000, 4.1.4, R73, SLES-15-750450240, 0582, 10.2.1.5, 10.2.1, 10.2, SV-234899r1009634_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/passwd" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/passwd $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/passwd$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/passwd -p wa -k audit_rules_usergroup_modification_passwd" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification_passwd.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/passwd" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/audit_rules_usergroup_modification_passwd.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification_passwd.rules"
# If the audit_rules_usergroup_modification_passwd.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/passwd" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/passwd $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/passwd$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/passwd -p wa -k audit_rules_usergroup_modification_passwd" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85577-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030000
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/passwd - Check if
watch rule for /etc/passwd already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/passwd\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85577-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030000
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/passwd - Search /etc/audit/rules.d
for other rules with specified key audit_rules_usergroup_modification_passwd
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification_passwd$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85577-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030000
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/passwd - Use /etc/audit/rules.d/audit_rules_usergroup_modification_passwd.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/audit_rules_usergroup_modification_passwd.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85577-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030000
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/passwd - Use matched
file as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85577-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030000
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/passwd - Add watch
rule for /etc/passwd in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /etc/passwd -p wa -k audit_rules_usergroup_modification_passwd
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85577-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030000
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/passwd - Check if
watch rule for /etc/passwd already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/etc/passwd\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85577-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030000
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/passwd - Add watch
rule for /etc/passwd in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/passwd -p wa -k audit_rules_usergroup_modification_passwd
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85577-5
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030000
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Events that Modify User/Group Information - /etc/shadow
[ref]rule
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /etc/shadow -p wa -k audit_rules_usergroup_modification
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules:
-w /etc/shadow -p wa -k audit_rules_usergroup_modification Rationale:In addition to auditing new user and group accounts, these watches
will alert the system administrator(s) to any modifications. Any unexpected
users, groups, or modifications should be investigated for legitimacy. Identifiers:
CCE-85579-1 References:
1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.1.7, 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e), 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, Req-10.2.5, SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000503-CTR-001275, SLES-15-030020, 4.1.4, R73, SLES-15-750450240, 0582, 10.2.1.5, 10.2.1, 10.2, SV-234901r1009636_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/shadow" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/shadow $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/shadow$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/shadow -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/shadow" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
# If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/etc/shadow" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/shadow $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/etc/shadow$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /etc/shadow -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85579-1
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030020
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/shadow - Check if
watch rule for /etc/shadow already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/shadow\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85579-1
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030020
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/shadow - Search /etc/audit/rules.d
for other rules with specified key audit_rules_usergroup_modification
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85579-1
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030020
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/shadow - Use /etc/audit/rules.d/audit_rules_usergroup_modification.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/audit_rules_usergroup_modification.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85579-1
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030020
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/shadow - Use matched
file as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-85579-1
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030020
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/shadow - Add watch
rule for /etc/shadow in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /etc/shadow -p wa -k audit_rules_usergroup_modification
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-85579-1
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030020
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/shadow - Check if
watch rule for /etc/shadow already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/etc/shadow\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85579-1
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030020
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/shadow - Add watch
rule for /etc/shadow in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/shadow -p wa -k audit_rules_usergroup_modification
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-85579-1
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030020
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Record Attempts to perform maintenance activities
[ref]ruleThe SUSE Linux Enterprise 15 operating system must generate audit records for
privileged activities, nonlocal maintenance, diagnostic sessions and
other system-level access.
Verify the operating system audits activities performed during nonlocal
maintenance and diagnostic sessions. Run the following command:
$ sudo auditctl -l | grep sudo.log
-w /var/log/sudo.log -p wa -k maintenance
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /var/log/sudo.log -p wa -k maintenance
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules:
-w /var/log/sudo.log -p wa -k maintenance Rationale:If events associated with nonlocal administrative access or diagnostic
sessions are not logged, a major tool for assessing and investigating
attacks would not be available.
This requirement addresses auditing-related issues associated with
maintenance tools used specifically for diagnostic and repair actions
on organizational information systems.
Nonlocal maintenance and diagnostic activities are those activities
conducted by individuals communicating through a network, either an
external network (e.g., the internet) or an internal network. Local
maintenance and diagnostic activities are those activities carried
out by individuals physically present at the information system or
information system component and not communicating across a network
connection.
This requirement applies to hardware/software diagnostic test
equipment or tools. This requirement does not cover hardware/software
components that may support information system maintenance, yet are a
part of the system, for example, the software implementing "ping,"
"ls," "ipconfig," or the hardware and software implementing the
monitoring port of an Ethernet switch. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
# into the list of files to be inspected
files_to_inspect+=('/etc/audit/audit.rules')
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/var/log/sudo.log" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/sudo.log $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/var/log/sudo.log$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /var/log/sudo.log -p wa -k maintenance" >> "$audit_rules_file"
fi
done
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/maintenance.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/log/sudo.log" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${matches[@]}"
do
# Extract filepath from the match
rulesd_audit_file=$(echo $match | cut -f1 -d ':')
# Append that path into list of files for inspection
files_to_inspect+=("$rulesd_audit_file")
done
# Case when particular audit rule isn't defined yet
if [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/maintenance.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/maintenance.rules"
# If the maintenance.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$key_rule_file" ]
then
touch "$key_rule_file"
chmod 0600 "$key_rule_file"
fi
files_to_inspect+=("$key_rule_file")
fi
# Finally perform the inspection and possible subsequent audit rule
# correction for each of the files previously identified for inspection
for audit_rules_file in "${files_to_inspect[@]}"
do
# Check if audit watch file system object rule for given path already present
if grep -q -P -- "^[\s]*-w[\s]+/var/log/sudo.log" "$audit_rules_file"
then
# Rule is found => verify yet if existing rule definition contains
# all of the required access type bits
# Define BRE whitespace class shortcut
sp="[[:space:]]"
# Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule
current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/sudo.log $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")
# Split required access bits string into characters array
# (to check bit's presence for one bit at a time)
for access_bit in $(echo "wa" | grep -o .)
do
# For each from the required access bits (e.g. 'w', 'a') check
# if they are already present in current access bits for rule.
# If not, append that bit at the end
if ! grep -q "$access_bit" <<< "$current_access_bits"
then
# Concatenate the existing mask with the missing bit
current_access_bits="$current_access_bits$access_bit"
fi
done
# Propagate the updated rule's access bits (original + the required
# ones) back into the /etc/audit/audit.rules file for that rule
sed -i "s#\($sp*-w$sp\+/var/log/sudo.log$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"
else
# Rule isn't present yet. Append it at the end of $audit_rules_file file
# with proper key
echo "-w /var/log/sudo.log -p wa -k maintenance" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92551-1
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_sudo_log_events
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to perform maintenance activities - Check if watch rule for
/var/log/sudo.log already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/var/log/sudo.log\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92551-1
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_sudo_log_events
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to perform maintenance activities - Search /etc/audit/rules.d
for other rules with specified key maintenance
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)maintenance$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-92551-1
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_sudo_log_events
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to perform maintenance activities - Use /etc/audit/rules.d/maintenance.rules
as the recipient for the rule
ansible.builtin.set_fact:
all_files:
- /etc/audit/rules.d/maintenance.rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-92551-1
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_sudo_log_events
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to perform maintenance activities - Use matched file as the
recipient for the rule
ansible.builtin.set_fact:
all_files:
- '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
is defined and find_existing_watch_rules_d.matched == 0
tags:
- CCE-92551-1
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_sudo_log_events
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to perform maintenance activities - Add watch rule for /var/log/sudo.log
in /etc/audit/rules.d/
ansible.builtin.lineinfile:
path: '{{ all_files[0] }}'
line: -w /var/log/sudo.log -p wa -k maintenance
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CCE-92551-1
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_sudo_log_events
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to perform maintenance activities - Check if watch rule for
/var/log/sudo.log already exists in /etc/audit/audit.rules
ansible.builtin.find:
paths: /etc/audit/
contains: ^\s*-w\s+/var/log/sudo.log\s+-p\s+wa(\s|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92551-1
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_sudo_log_events
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to perform maintenance activities - Add watch rule for /var/log/sudo.log
in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /var/log/sudo.log -p wa -k maintenance
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CCE-92551-1
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_sudo_log_events
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
System Audit Logs Must Have Mode 0750 or Less Permissive
[ref]rule
If log_group in /etc/audit/auditd.conf is set to a group other than the root
group account, change the mode of the audit log files with the following command:
$ sudo chmod 0750 /var/log/audit
Otherwise, change the mode of the audit log files with the following command:
$ sudo chmod 0700 /var/log/audit Rationale:If users can write to audit logs, audit trails can be modified or destroyed. Identifiers:
CCE-92530-5 References:
1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8, APO01.06, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA02.01, 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.2, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-004-6 R3.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CIP-007-3 R6.5, CM-6(a), AC-6(1), AU-9, DE.AE-3, DE.AE-5, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4, SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SLES-15-750450540 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -iw ^log_file /etc/audit/auditd.conf; then
DIR=$(awk -F "=" '/^log_file/ {print $2}' /etc/audit/auditd.conf | tr -d ' ' | rev | cut -d"/" -f2- | rev)
else
DIR="/var/log/audit"
fi
if LC_ALL=C grep -m 1 -q ^log_group /etc/audit/auditd.conf; then
GROUP=$(awk -F "=" '/log_group/ {print $2}' /etc/audit/auditd.conf | tr -d ' ')
if ! [ "${GROUP}" == 'root' ] ; then
chmod 0750 $DIR
else
chmod 0700 $DIR
fi
else
chmod 0700 $DIR
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92530-5
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9
- NIST-800-53-CM-6(a)
- directory_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Have Mode 0750 or Less Permissive - Get audit log file
from /etc/audit/auditd.conf
ansible.builtin.command: grep -iw ^log_file /etc/audit/auditd.conf
check_mode: false
failed_when: false
changed_when: false
register: log_file_exists
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92530-5
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9
- NIST-800-53-CM-6(a)
- directory_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Have Mode 0750 or Less Permissive - Set audit log file
fact
ansible.builtin.set_fact:
log_file_line: '{{ log_file_exists.stdout | split('' '') | last }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92530-5
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9
- NIST-800-53-CM-6(a)
- directory_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Have Mode 0750 or Less Permissive - Set default log_file
if not configured in /etc/audit/auditd.conf
ansible.builtin.set_fact:
log_file_dir: /var/log/audit
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- (log_file_exists is undefined) or (log_file_exists.stdout | length == 0)
tags:
- CCE-92530-5
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9
- NIST-800-53-CM-6(a)
- directory_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Have Mode 0750 or Less Permissive - Set log_file_dir
from log_file_line if configured
ansible.builtin.set_fact:
log_file_dir: '{{ log_file_line | dirname}}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- (log_file_line is defined) and (log_file_line | length > 0)
tags:
- CCE-92530-5
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9
- NIST-800-53-CM-6(a)
- directory_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Have Mode 0750 or Less Permissive - Get audit log group
ansible.builtin.command: grep -iw ^log_group /etc/audit/auditd.conf
check_mode: false
failed_when: false
changed_when: false
register: log_group_exists
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92530-5
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9
- NIST-800-53-CM-6(a)
- directory_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Have Mode 0750 or Less Permissive - Set audit log directory
mode to 0700
ansible.builtin.file:
path: '{{ log_file_dir }}'
mode: 448
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- log_group_exists.stdout | length == 0
tags:
- CCE-92530-5
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9
- NIST-800-53-CM-6(a)
- directory_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Have Mode 0750 or Less Permissive - Set audit log directory
mode to 0750
ansible.builtin.file:
path: '{{ log_file_dir }}'
mode: 488
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- log_group_exists.stdout | length > 0
tags:
- CCE-92530-5
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9
- NIST-800-53-CM-6(a)
- directory_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
System Audit Logs Must Be Group Owned By Root
[ref]ruleAll audit logs must be group owned by root user. The path for audit log can
be configured via log_file parameter in /etc/audit/auditd.conf
or, by default, the path for audit log is /var/log/audit/ .
To properly set the group owner of /var/log/audit/*, run the command:
$ sudo chgrp root /var/log/audit/*
If log_group in /etc/audit/auditd.conf is set to a group other
than the root group account, change the group ownership of the audit logs
to this specific group.Rationale:Unauthorized disclosure of audit records can reveal system and configuration data to
attackers, thus compromising its confidentiality. Identifiers:
CCE-92534-7 References:
1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO01.06, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA02.01, 3.3.1, 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), AU-9(4), DE.AE-3, DE.AE-5, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.5.1, SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000206-GPOS-00084, SLES-15-750450585, 10.3.2, 10.3 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -iw log_file /etc/audit/auditd.conf; then
FILE=$(awk -F "=" '/^log_file/ {print $2}' /etc/audit/auditd.conf | tr -d ' ')
else
FILE="/var/log/audit/audit.log"
fi
if LC_ALL=C grep -m 1 -q ^log_group /etc/audit/auditd.conf; then
GROUP=$(awk -F "=" '/log_group/ {print $2}' /etc/audit/auditd.conf | tr -d ' ')
if ! [ "${GROUP}" == 'root' ]; then
chgrp ${GROUP} $FILE*
else
chgrp root $FILE*
fi
else
chgrp root $FILE*
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92534-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- file_group_ownership_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Group Owned By Root - Get Audit Log Files
ansible.builtin.command: grep -iw ^log_file /etc/audit/auditd.conf
failed_when: false
changed_when: false
check_mode: false
register: log_file_exists
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92534-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- file_group_ownership_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Group Owned By Root - Set Log File Facts
ansible.builtin.set_fact:
log_file_line: '{{ log_file_exists.stdout | split('' '') | last }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92534-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- file_group_ownership_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Group Owned By Root - Set Default log_file if Not
Set
ansible.builtin.set_fact:
log_file: /var/log/audit/audit.log
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- (log_file_exists is undefined) or (log_file_exists.stdout | length == 0)
tags:
- CCE-92534-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- file_group_ownership_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Group Owned By Root - Set log_file From log_file_line
if Not Set Already
ansible.builtin.set_fact:
log_file: '{{ log_file_line }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- (log_file_line is defined) and (log_file_line | length > 0)
tags:
- CCE-92534-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- file_group_ownership_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Group Owned By Root - Get All Log File Backups
ansible.builtin.find:
path: '{{ log_file | dirname }}'
patterns: '{{ log_file | basename }}.*'
register: backup_files
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92534-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- file_group_ownership_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Group Owned By Root - Get Audit Log Group
ansible.builtin.command: grep -iw ^log_group /etc/audit/auditd.conf
failed_when: false
changed_when: false
check_mode: false
register: log_group_exists
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92534-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- file_group_ownership_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Group Owned By Root - Set Log Group Facts
ansible.builtin.set_fact:
log_group_line: '{{ log_group_exists.stdout | split('' '') | last }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92534-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- file_group_ownership_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Group Owned By Root - Set Default log_group if Not
Set
ansible.builtin.set_fact:
log_group: root
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- (log_group_exists is undefined) or (log_group_exists.stdout | length == 0)
tags:
- CCE-92534-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- file_group_ownership_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Group Owned By Root - Set log_group From log_group_line
if Not Set Already
ansible.builtin.set_fact:
log_group: '{{ log_group_line }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- (log_group_line is defined) and (log_group_line | length > 0)
tags:
- CCE-92534-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- file_group_ownership_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Group Owned By Root - Apply Mode to All Backup Log
Files
ansible.builtin.file:
path: '{{ item }}'
group: '{{ log_group }}'
failed_when: false
loop: '{{ backup_files.files| map(attribute=''path'') | list }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92534-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- file_group_ownership_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Group Owned By Root - Apply Mode to Log File
ansible.builtin.file:
path: '{{ log_file }}'
group: '{{ log_group }}'
failed_when: false
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92534-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- file_group_ownership_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Audit Configuration Files Must Be Owned By Group root
[ref]ruleAll audit configuration files must be owned by group root.
chown :root /etc/audit/audit*.{rules,conf} /etc/audit/rules.d/*Rationale:Without the capability to restrict which roles and individuals can
select which events are audited, unauthorized personnel may be able
to prevent the auditing of critical events.
Misconfigured audits may degrade the system's performance by
overwhelming the audit log. Misconfigured audits may also make it more
difficult to establish, correlate, and investigate the events relating
to an incident or identify those responsible for one. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
find -P /etc/audit/ -maxdepth 1 -type f ! -group 0 -regextype posix-extended -regex '^.*audit(\.rules|d\.conf)$' -exec chgrp --no-dereference "$newgroup" {} \;
find -P /etc/audit/rules.d/ -maxdepth 1 -type f ! -group 0 -regextype posix-extended -regex '^.*\.rules$' -exec chgrp --no-dereference "$newgroup" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92544-6
- configure_strategy
- file_groupownership_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_groupownership_audit_configuration_newgroup variable if represented
by gid
ansible.builtin.set_fact:
file_groupownership_audit_configuration_newgroup: '0'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92544-6
- configure_strategy
- file_groupownership_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/audit/ file(s) matching ^.*audit(\.rules|d\.conf)$
ansible.builtin.command: find -P /etc/audit/ -maxdepth 1 -type f ! -group 0 -regextype
posix-extended -regex "^.*audit(\.rules|d\.conf)$"
register: files_found
changed_when: false
failed_when: false
check_mode: false
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92544-6
- configure_strategy
- file_groupownership_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/audit/ file(s) matching ^.*audit(\.rules|d\.conf)$
ansible.builtin.file:
path: '{{ item }}'
follow: false
group: '{{ file_groupownership_audit_configuration_newgroup }}'
state: file
with_items:
- '{{ files_found.stdout_lines }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92544-6
- configure_strategy
- file_groupownership_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/audit/rules.d/ file(s) matching ^.*\.rules$
ansible.builtin.command: find -P /etc/audit/rules.d/ -maxdepth 1 -type f ! -group
0 -regextype posix-extended -regex "^.*\.rules$"
register: files_found
changed_when: false
failed_when: false
check_mode: false
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92544-6
- configure_strategy
- file_groupownership_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/audit/rules.d/ file(s) matching ^.*\.rules$
ansible.builtin.file:
path: '{{ item }}'
follow: false
group: '{{ file_groupownership_audit_configuration_newgroup }}'
state: file
with_items:
- '{{ files_found.stdout_lines }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92544-6
- configure_strategy
- file_groupownership_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Audit Configuration Files Must Be Owned By Root
[ref]ruleAll audit configuration files must be owned by root user.
To properly set the owner of /etc/audit/, run the command:
$ sudo chown root /etc/audit/
To properly set the owner of /etc/audit/rules.d/, run the command:
$ sudo chown root /etc/audit/rules.d/
Rationale:Without the capability to restrict which roles and individuals can
select which events are audited, unauthorized personnel may be able
to prevent the auditing of critical events.
Misconfigured audits may degrade the system's performance by
overwhelming the audit log. Misconfigured audits may also make it more
difficult to establish, correlate, and investigate the events relating
to an incident or identify those responsible for one. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
find -P /etc/audit/ -maxdepth 1 -type f ! -user 0 -regextype posix-extended -regex '^.*audit(\.rules|d\.conf)$' -exec chown --no-dereference "$newown" {} \;
find -P /etc/audit/rules.d/ -maxdepth 1 -type f ! -user 0 -regextype posix-extended -regex '^.*\.rules$' -exec chown --no-dereference "$newown" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92550-3
- configure_strategy
- file_ownership_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_ownership_audit_configuration_newown variable if represented
by uid
ansible.builtin.set_fact:
file_ownership_audit_configuration_newown: '0'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92550-3
- configure_strategy
- file_ownership_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/audit/ file(s) matching ^.*audit(\.rules|d\.conf)$
ansible.builtin.command: find -P /etc/audit/ -maxdepth 1 -type f ! -user 0 -regextype
posix-extended -regex "^.*audit(\.rules|d\.conf)$"
register: files_found
changed_when: false
failed_when: false
check_mode: false
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92550-3
- configure_strategy
- file_ownership_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/audit/ file(s) matching ^.*audit(\.rules|d\.conf)$
ansible.builtin.file:
path: '{{ item }}'
follow: false
owner: '{{ file_ownership_audit_configuration_newown }}'
state: file
with_items:
- '{{ files_found.stdout_lines }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92550-3
- configure_strategy
- file_ownership_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/audit/rules.d/ file(s) matching ^.*\.rules$
ansible.builtin.command: find -P /etc/audit/rules.d/ -maxdepth 1 -type f ! -user
0 -regextype posix-extended -regex "^.*\.rules$"
register: files_found
changed_when: false
failed_when: false
check_mode: false
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92550-3
- configure_strategy
- file_ownership_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/audit/rules.d/ file(s) matching ^.*\.rules$
ansible.builtin.file:
path: '{{ item }}'
follow: false
owner: '{{ file_ownership_audit_configuration_newown }}'
state: file
with_items:
- '{{ files_found.stdout_lines }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92550-3
- configure_strategy
- file_ownership_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
System Audit Logs Must Be Owned By Root
[ref]ruleAll audit logs must be owned by root user. The path for audit log can be
configured via log_file parameter in /etc/audit/auditd.conf
or by default, the path for audit log is /var/log/audit/ .
To properly set the owner of /var/log/audit/*, run the command:
$ sudo chown root /var/log/audit/*
Rationale:Unauthorized disclosure of audit records can reveal system and configuration data to
attackers, thus compromising its confidentiality. Identifiers:
CCE-92553-7 References:
1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO01.06, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA02.01, 3.3.1, 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), AU-9(4), DE.AE-3, DE.AE-5, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.5.1, SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000206-GPOS-00084, SLES-15-750450570 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -iw log_file /etc/audit/auditd.conf; then
FILE=$(awk -F "=" '/^log_file/ {print $2}' /etc/audit/auditd.conf | tr -d ' ')
chown root $FILE*
else
chown root /var/log/audit/audit.log*
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92553-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- file_ownership_var_log_audit_stig
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Owned By Root - Get audit log file from /etc/audit/auditd.conf
ansible.builtin.command: grep -iw ^log_file /etc/audit/auditd.conf
check_mode: false
failed_when: false
changed_when: false
register: log_file_exists
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92553-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- file_ownership_var_log_audit_stig
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Owned By Root - Set audit log file fact
ansible.builtin.set_fact:
log_file_line: '{{ log_file_exists.stdout | split('' '') | last }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92553-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- file_ownership_var_log_audit_stig
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Owned By Root - Set default log_file if not configured
in /etc/audit/auditd.conf
ansible.builtin.set_fact:
log_file: /var/log/audit/audit.log
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- (log_file_exists is undefined) or (log_file_exists.stdout | length == 0)
tags:
- CCE-92553-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- file_ownership_var_log_audit_stig
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Owned By Root - Set log_file from log_file_line
if configured
ansible.builtin.set_fact:
log_file: '{{ log_file_line }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- (log_file_line is defined) and (log_file_line | length > 0)
tags:
- CCE-92553-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- file_ownership_var_log_audit_stig
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Owned By Root - Get all audit backup log file(s)
ansible.builtin.find:
path: '{{ log_file | dirname }}'
patterns: '{{ log_file | basename }}.*'
register: backup_files
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92553-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- file_ownership_var_log_audit_stig
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Owned By Root - Set root as owner to all audit backup
log file(s)
ansible.builtin.file:
path: '{{ item }}'
owner: root
loop: '{{ backup_files.files| map(attribute=''path'') | list }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92553-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- file_ownership_var_log_audit_stig
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: System Audit Logs Must Be Owned By Root - Set root as owner to audit log file
ansible.builtin.file:
path: '{{ log_file }}'
owner: root
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92553-7
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- file_ownership_var_log_audit_stig
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Audit Configuration Files Permissions are 640 or More Restrictive
[ref]ruleAll audit configuration files permissions must be 640 or more restrictive.
chmod 0640 /etc/audit/audit*.{rules,conf} /etc/audit/rules.d/*Rationale:Without the capability to restrict which roles and individuals can
select which events are audited, unauthorized personnel may be able
to prevent the auditing of critical events.
Misconfigured audits may degrade the system's performance by
overwhelming the audit log. Misconfigured audits may also make it more
difficult to establish, correlate, and investigate the events relating
to an incident or identify those responsible for one. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
find -P /etc/audit/ -maxdepth 1 -perm /u+xs,g+xws,o+xwrt -type f -regextype posix-extended -regex '^.*audit(\.rules|d\.conf)$' -exec chmod u-xs,g-xws,o-xwrt {} \;
find -P /etc/audit/rules.d/ -maxdepth 1 -perm /u+xs,g+xws,o+xwrt -type f -regextype posix-extended -regex '^.*\.rules$' -exec chmod u-xs,g-xws,o-xwrt {} \;
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92557-8
- NIST-800-53-AU-12 b
- configure_strategy
- file_permissions_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/audit/ file(s)
ansible.builtin.command: find -P /etc/audit/ -maxdepth 1 -perm /u+xs,g+xws,o+xwrt -type
f -regextype posix-extended -regex "^.*audit(\.rules|d\.conf)$"
register: files_found
changed_when: false
failed_when: false
check_mode: false
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92557-8
- NIST-800-53-AU-12 b
- configure_strategy
- file_permissions_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set permissions for /etc/audit/ file(s)
ansible.builtin.file:
path: '{{ item }}'
mode: u-xs,g-xws,o-xwrt
state: file
with_items:
- '{{ files_found.stdout_lines }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92557-8
- NIST-800-53-AU-12 b
- configure_strategy
- file_permissions_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Find /etc/audit/rules.d/ file(s)
ansible.builtin.command: find -P /etc/audit/rules.d/ -maxdepth 1 -perm /u+xs,g+xws,o+xwrt -type
f -regextype posix-extended -regex "^.*\.rules$"
register: files_found
changed_when: false
failed_when: false
check_mode: false
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92557-8
- NIST-800-53-AU-12 b
- configure_strategy
- file_permissions_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set permissions for /etc/audit/rules.d/ file(s)
ansible.builtin.file:
path: '{{ item }}'
mode: u-xs,g-xws,o-xwrt
state: file
with_items:
- '{{ files_found.stdout_lines }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92557-8
- NIST-800-53-AU-12 b
- configure_strategy
- file_permissions_audit_configuration
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
System Audit Logs Must Have Mode 0640 or Less Permissive
[ref]rule
If log_group in /etc/audit/auditd.conf is set to a group other than the
root
group account, change the mode of the audit log files with the following command:
$ sudo chmod 0640 audit_file
Otherwise, change the mode of the audit log files with the following command:
$ sudo chmod 0600 audit_file Rationale:If users can write to audit logs, audit trails can be modified or destroyed. Identifiers:
CCE-85811-8 References:
1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO01.06, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA02.01, 3.3.1, 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), AU-9(4), DE.AE-3, DE.AE-5, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.5, SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000206-GPOS-00084, SRG-APP-000118-CTR-000240, SLES-15-750450555, 10.3.1, 10.3 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
if LC_ALL=C grep -iw ^log_file /etc/audit/auditd.conf; then
FILE=$(awk -F "=" '/^log_file/ {print $2}' /etc/audit/auditd.conf | tr -d ' ')
else
FILE="/var/log/audit/audit.log"
fi
if LC_ALL=C grep -m 1 -q ^log_group /etc/audit/auditd.conf; then
GROUP=$(awk -F "=" '/log_group/ {print $2}' /etc/audit/auditd.conf | tr -d ' ')
if ! [ "${GROUP}" == 'root' ] ; then
chmod 0640 $FILE
chmod 0440 $FILE.*
else
chmod 0600 $FILE
chmod 0400 $FILE.*
fi
else
chmod 0600 $FILE
chmod 0400 $FILE.*
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85811-8
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- file_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Get audit log files
ansible.builtin.command: grep -iw ^log_file /etc/audit/auditd.conf
failed_when: false
changed_when: false
check_mode: false
register: log_file_exists
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85811-8
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- file_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Parse log file line
ansible.builtin.command: awk -F '=' '/^log_file/ {print $2}' /etc/audit/auditd.conf
register: log_file_line
changed_when: false
check_mode: false
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- log_file_exists is not skipped and (log_file_exists.stdout | length > 0)
tags:
- CCE-85811-8
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- file_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Set default log_file if not set
ansible.builtin.set_fact:
log_file: /var/log/audit/audit.log
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- (log_file_exists is skipped) or (log_file_exists is undefined) or (log_file_exists.stdout
| length == 0)
tags:
- CCE-85811-8
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- file_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Set log_file from log_file_line if not set already
ansible.builtin.set_fact:
log_file: '{{ log_file_line.stdout | trim }}'
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- (log_file_exists is not skipped) and (log_file_line.stdout is defined) and (log_file_line.stdout
| length > 0)
tags:
- CCE-85811-8
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- file_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Get log files group
ansible.builtin.command: grep -m 1 ^log_group /etc/audit/auditd.conf
failed_when: false
changed_when: false
check_mode: false
register: log_group_line
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85811-8
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- file_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Parse log group line
ansible.builtin.command: awk -F '=' '/log_group/ {print $2}' /etc/audit/auditd.conf
changed_when: false
check_mode: false
register: log_group
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- (log_group_line is not skipped) and (log_group_line.stdout | length > 0)
tags:
- CCE-85811-8
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- file_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Apply mode to log file when group root
ansible.builtin.file:
path: '{{ log_file }}'
mode: (( log_group is defined ) and ( ( log_group.stdout | trim ) == 'root' ))
| ternary( '0600', '0640')
failed_when: false
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- log_group is not skipped
tags:
- CCE-85811-8
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- file_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: List all log file backups
ansible.builtin.find:
path: '{{ log_file | dirname }}'
patterns: '{{ log_file | basename }}.*'
register: backup_files
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85811-8
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- file_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Apply mode to log file when group not root
ansible.builtin.file:
path: '{{ item }}'
mode: (( log_group is defined ) and ( ( log_group.stdout | trim ) == 'root' )) |
ternary( '0400', '0440')
loop: '{{ backup_files.files| map(attribute=''path'') | list }}'
failed_when: false
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- backup_files is not skipped
tags:
- CCE-85811-8
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-6(1)
- NIST-800-53-AU-9(4)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- file_permissions_var_log_audit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Configure auditd Data Retention
[ref]groupThe audit system writes data to /var/log/audit/audit.log. By default,
auditd rotates 5 logs by size (6MB), retaining a maximum of 30MB of
data in total, and refuses to write entries when the disk is too
full. This minimizes the risk of audit data filling its partition
and impacting other services. This also minimizes the risk of the audit
daemon temporarily disabling the system if it cannot write audit log (which
it can be configured to do).
For a busy
system or a system which is thoroughly auditing system activity, the default settings
for data retention may be
insufficient. The log file size needed will depend heavily on what types
of events are being audited. First configure auditing to log all the events of
interest. Then monitor the log size manually for awhile to determine what file
size will allow you to keep the required data for the correct time period.
Using a dedicated partition for /var/log/audit prevents the
auditd logs from disrupting system functionality if they fill, and,
more importantly, prevents other activity in /var from filling the
partition and stopping the audit trail. (The audit logs are size-limited and
therefore unlikely to grow without bound unless configured to do so.) Some
machines may have requirements that no actions occur which cannot be audited.
If this is the case, then auditd can be configured to halt the machine
if it runs out of space. Note: Since older logs are rotated,
configuring auditd this way does not prevent older logs from being
rotated away before they can be viewed.
If your system is configured to halt when logging cannot be performed, make
sure this can never happen under normal circumstances! Ensure that
/var/log/audit is on its own partition, and that this partition is
larger than the maximum amount of data auditd will retain
normally. |
| contains 5 rules |
Configure auditd mail_acct Action on Low Disk Space
[ref]ruleThe auditd service can be configured to send email to
a designated account in certain situations. Add or correct the following line
in /etc/audit/auditd.conf to ensure that administrators are notified
via email for those situations:
action_mail_acct = root Rationale:Email sent to the root account is typically aliased to the
administrators of the system, who can take appropriate action. Identifiers:
CCE-85604-7 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO11.04, APO12.06, APO13.01, BAI03.05, BAI04.04, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, MEA02.01, 3.3.1, 164.312(a)(2)(ii), 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 7.1, SR 7.2, A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.16.1.4, A.16.1.5, A.16.1.7, A.17.2.1, CIP-003-8 R1.3, CIP-003-8 R3, CIP-003-8 R3.1, CIP-003-8 R3.2, CIP-003-8 R3.3, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, IA-5(1), AU-5(a), AU-5(2), CM-6(a), DE.AE-3, DE.AE-5, PR.DS-4, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.7.a, SRG-OS-000046-GPOS-00022, SRG-OS-000343-GPOS-00134, SLES-15-030570, 4.1.2.3, SLES-15-750450105, SLES-15-750450120, SV-234956r958424_rule Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_auditd_action_mail_acct='root'
AUDITCONFIG=/etc/audit/auditd.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^action_mail_acct")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_auditd_action_mail_acct"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^action_mail_acct\\>" "$AUDITCONFIG"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^action_mail_acct\\>.*/$escaped_formatted_output/gi" "$AUDITCONFIG"
else
if [[ -s "$AUDITCONFIG" ]] && [[ -n "$(tail -c 1 -- "$AUDITCONFIG" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "$AUDITCONFIG"
fi
cce="CCE-85604-7"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "$AUDITCONFIG" >> "$AUDITCONFIG"
printf '%s\n' "$formatted_output" >> "$AUDITCONFIG"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85604-7
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030570
- NIST-800-171-3.3.1
- NIST-800-53-AU-5(2)
- NIST-800-53-AU-5(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)
- PCI-DSS-Req-10.7.a
- auditd_data_retention_action_mail_acct
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_auditd_action_mail_acct # promote to variable
set_fact:
var_auditd_action_mail_acct: !!str root
tags:
- always
- name: Configure auditd mail_acct Action on Low Disk Space - Configure auditd mail_acct
Action on Low Disk Space
ansible.builtin.lineinfile:
dest: /etc/audit/auditd.conf
regexp: ^action_mail_acct
line: action_mail_acct = {{ var_auditd_action_mail_acct }}
state: present
create: true
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85604-7
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030570
- NIST-800-171-3.3.1
- NIST-800-53-AU-5(2)
- NIST-800-53-AU-5(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)
- PCI-DSS-Req-10.7.a
- auditd_data_retention_action_mail_acct
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Configure auditd admin_space_left Action on Low Disk Space
[ref]ruleThe auditd service can be configured to take an action
when disk space is running low but prior to running out of space completely.
Edit the file /etc/audit/auditd.conf. Add or modify the following line,
substituting ACTION appropriately:
admin_space_left_action = ACTION
Set this value to single to cause the system to switch to single user
mode for corrective action. Acceptable values also include suspend and
halt. For certain systems, the need for availability
outweighs the need to log all actions, and a different setting should be
determined. Details regarding all possible values for ACTION are described in the
auditd.conf man page.Rationale:Administrators should be made aware of an inability to record
audit records. If a separate partition or logical volume of adequate size
is used, running low on space for audit records should never occur. Identifiers:
CCE-85824-1 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO11.04, APO12.06, APO13.01, BAI03.05, BAI04.04, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, MEA02.01, 3.3.1, 164.312(a)(2)(ii), 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 7.1, SR 7.2, A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.16.1.4, A.16.1.5, A.16.1.7, A.17.2.1, AU-5(b), AU-5(2), AU-5(1), AU-5(4), CM-6(a), DE.AE-3, DE.AE-5, PR.DS-4, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.7, SRG-OS-000343-GPOS-00134, 4.1.2.3, SLES-15-750450105, SLES-15-750450120, 10.5.1, 10.5 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_auditd_admin_space_left_action='halt'
var_auditd_admin_space_left_action="$(echo $var_auditd_admin_space_left_action | cut -d \| -f 1)"
AUDITCONFIG=/etc/audit/auditd.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^admin_space_left_action")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_auditd_admin_space_left_action"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^admin_space_left_action\\>" "$AUDITCONFIG"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^admin_space_left_action\\>.*/$escaped_formatted_output/gi" "$AUDITCONFIG"
else
if [[ -s "$AUDITCONFIG" ]] && [[ -n "$(tail -c 1 -- "$AUDITCONFIG" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "$AUDITCONFIG"
fi
cce="CCE-85824-1"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "$AUDITCONFIG" >> "$AUDITCONFIG"
printf '%s\n' "$formatted_output" >> "$AUDITCONFIG"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85824-1
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AU-5(1)
- NIST-800-53-AU-5(2)
- NIST-800-53-AU-5(4)
- NIST-800-53-AU-5(b)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- PCI-DSSv4-10.5
- PCI-DSSv4-10.5.1
- auditd_data_retention_admin_space_left_action
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_auditd_admin_space_left_action # promote to variable
set_fact:
var_auditd_admin_space_left_action: !!str halt
tags:
- always
- name: Configure auditd admin_space_left Action on Low Disk Space
ansible.builtin.lineinfile:
dest: /etc/audit/auditd.conf
line: admin_space_left_action = {{ var_auditd_admin_space_left_action .split('|')[0]
}}
regexp: ^\s*admin_space_left_action\s*=\s*.*$
state: present
create: true
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85824-1
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AU-5(1)
- NIST-800-53-AU-5(2)
- NIST-800-53-AU-5(4)
- NIST-800-53-AU-5(b)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- PCI-DSSv4-10.5
- PCI-DSSv4-10.5.1
- auditd_data_retention_admin_space_left_action
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Configure auditd Max Log File Size
[ref]ruleDetermine the amount of audit data (in megabytes)
which should be retained in each log file. Edit the file
/etc/audit/auditd.conf. Add or modify the following line, substituting
the correct value of 6 for STOREMB:
max_log_file = STOREMB
Set the value to 6 (MB) or higher for general-purpose systems.
Larger values, of course,
support retention of even more audit data.Rationale:The total storage for audit log files must be large enough to retain
log information over the period required. This is a function of the maximum
log file size and the number of logs retained. Identifiers:
CCE-85825-8 References:
1, 11, 12, 13, 14, 15, 16, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, MEA02.01, 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.16.1.4, A.16.1.5, A.16.1.7, CIP-004-6 R2.2.3, CIP-004-6 R3.3, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CIP-007-3 R6.5, AU-11, CM-6(a), DE.AE-3, DE.AE-5, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.7, 4.1.2.1, SLES-15-750450075 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_auditd_max_log_file='6'
AUDITCONFIG=/etc/audit/auditd.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^max_log_file")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_auditd_max_log_file"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^max_log_file\\>" "$AUDITCONFIG"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^max_log_file\\>.*/$escaped_formatted_output/gi" "$AUDITCONFIG"
else
if [[ -s "$AUDITCONFIG" ]] && [[ -n "$(tail -c 1 -- "$AUDITCONFIG" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "$AUDITCONFIG"
fi
cce="CCE-85825-8"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "$AUDITCONFIG" >> "$AUDITCONFIG"
printf '%s\n' "$formatted_output" >> "$AUDITCONFIG"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85825-8
- CJIS-5.4.1.1
- NIST-800-53-AU-11
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- auditd_data_retention_max_log_file
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_auditd_max_log_file # promote to variable
set_fact:
var_auditd_max_log_file: !!str 6
tags:
- always
- name: Configure auditd Max Log File Size
ansible.builtin.lineinfile:
dest: /etc/audit/auditd.conf
regexp: ^\s*max_log_file\s*=\s*.*$
line: max_log_file = {{ var_auditd_max_log_file }}
state: present
create: true
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85825-8
- CJIS-5.4.1.1
- NIST-800-53-AU-11
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- auditd_data_retention_max_log_file
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Configure auditd max_log_file_action Upon Reaching Maximum Log Size
[ref]ruleThe default action to take when the logs reach their maximum size
is to rotate the log files, discarding the oldest one. To configure the action taken
by auditd, add or correct the line in /etc/audit/auditd.conf:
max_log_file_action = ACTION
Possible values for ACTION are described in the auditd.conf man
page. These include:
ignoresyslogsuspendrotatekeep_logs
Set the ACTION to keep_logs.
The setting is case-insensitive.Rationale:Automatically rotating logs (by setting this to rotate)
minimizes the chances of the system unexpectedly running out of disk space by
being overwhelmed with log data. However, for systems that must never discard
log data, or which use external processes to transfer it and reclaim space,
keep_logs can be employed. Identifiers:
CCE-85778-9 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO11.04, APO12.06, APO13.01, BAI03.05, BAI04.04, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, MEA02.01, 164.312(a)(2)(ii), 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 7.1, SR 7.2, A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.16.1.4, A.16.1.5, A.16.1.7, A.17.2.1, AU-5(b), AU-5(2), AU-5(1), AU-5(4), CM-6(a), DE.AE-3, DE.AE-5, PR.DS-4, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.7, SRG-OS-000047-GPOS-00023, 4.1.2.2, SLES-15-750450090 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_auditd_max_log_file_action='keep_logs'
AUDITCONFIG=/etc/audit/auditd.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^max_log_file_action")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_auditd_max_log_file_action"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^max_log_file_action\\>" "$AUDITCONFIG"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^max_log_file_action\\>.*/$escaped_formatted_output/gi" "$AUDITCONFIG"
else
if [[ -s "$AUDITCONFIG" ]] && [[ -n "$(tail -c 1 -- "$AUDITCONFIG" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "$AUDITCONFIG"
fi
cce="CCE-85778-9"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "$AUDITCONFIG" >> "$AUDITCONFIG"
printf '%s\n' "$formatted_output" >> "$AUDITCONFIG"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85778-9
- CJIS-5.4.1.1
- NIST-800-53-AU-5(1)
- NIST-800-53-AU-5(2)
- NIST-800-53-AU-5(4)
- NIST-800-53-AU-5(b)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- auditd_data_retention_max_log_file_action
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_auditd_max_log_file_action # promote to variable
set_fact:
var_auditd_max_log_file_action: !!str keep_logs
tags:
- always
- name: Configure auditd max_log_file_action Upon Reaching Maximum Log Size
ansible.builtin.lineinfile:
dest: /etc/audit/auditd.conf
line: max_log_file_action = {{ var_auditd_max_log_file_action }}
regexp: ^\s*max_log_file_action\s*=\s*.*$
state: present
create: true
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85778-9
- CJIS-5.4.1.1
- NIST-800-53-AU-5(1)
- NIST-800-53-AU-5(2)
- NIST-800-53-AU-5(4)
- NIST-800-53-AU-5(b)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- auditd_data_retention_max_log_file_action
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
Configure auditd space_left Action on Low Disk Space
[ref]ruleThe auditd service can be configured to take an action
when disk space starts to run low.
Edit the file /etc/audit/auditd.conf. Modify the following line,
substituting ACTION appropriately:
space_left_action = ACTION
Possible values for ACTION are described in the auditd.conf man page.
These include:
syslogemailexecsuspendsinglehalt
Set this to email (instead of the default,
which is suspend) as it is more likely to get prompt attention. Acceptable values
also include suspend, single, and halt.Rationale:Notifying administrators of an impending disk space problem may
allow them to take corrective action prior to any disruption. Identifiers:
CCE-85823-3 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO11.04, APO12.06, APO13.01, BAI03.05, BAI04.04, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, MEA02.01, 3.3.1, 164.312(a)(2)(ii), 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 7.1, SR 7.2, A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.16.1.4, A.16.1.5, A.16.1.7, A.17.2.1, AU-5(b), AU-5(2), AU-5(1), AU-5(4), CM-6(a), DE.AE-3, DE.AE-5, PR.DS-4, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.7, SRG-OS-000343-GPOS-00134, 4.1.2.3, SLES-15-750450105, SLES-15-750450120, 10.5.1, 10.5 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
var_auditd_space_left_action='email'
var_auditd_space_left_action="$(echo $var_auditd_space_left_action | cut -d \| -f 1)"
#
# If space_left_action present in /etc/audit/auditd.conf, change value
# to var_auditd_space_left_action, else
# add "space_left_action = $var_auditd_space_left_action" to /etc/audit/auditd.conf
#
AUDITCONFIG=/etc/audit/auditd.conf
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^space_left_action")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_auditd_space_left_action"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^space_left_action\\>" "$AUDITCONFIG"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^space_left_action\\>.*/$escaped_formatted_output/gi" "$AUDITCONFIG"
else
if [[ -s "$AUDITCONFIG" ]] && [[ -n "$(tail -c 1 -- "$AUDITCONFIG" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "$AUDITCONFIG"
fi
cce="CCE-85823-3"
printf '# Per %s: Set %s in %s\n' "${cce}" "${formatted_output}" "$AUDITCONFIG" >> "$AUDITCONFIG"
printf '%s\n' "$formatted_output" >> "$AUDITCONFIG"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85823-3
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AU-5(1)
- NIST-800-53-AU-5(2)
- NIST-800-53-AU-5(4)
- NIST-800-53-AU-5(b)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- PCI-DSSv4-10.5
- PCI-DSSv4-10.5.1
- auditd_data_retention_space_left_action
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_auditd_space_left_action # promote to variable
set_fact:
var_auditd_space_left_action: !!str email
tags:
- always
- name: Configure auditd space_left Action on Low Disk Space
ansible.builtin.lineinfile:
dest: /etc/audit/auditd.conf
line: space_left_action = {{ var_auditd_space_left_action.split('|')[0] }}
regexp: ^\s*space_left_action\s*=\s*.*$
state: present
create: true
when:
- '"audit" in ansible_facts.packages'
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85823-3
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AU-5(1)
- NIST-800-53-AU-5(2)
- NIST-800-53-AU-5(4)
- NIST-800-53-AU-5(b)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.7
- PCI-DSSv4-10.5
- PCI-DSSv4-10.5.1
- auditd_data_retention_space_left_action
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
System Accounting with auditd
[ref]groupThe audit service provides substantial capabilities
for recording system activities. This section
deals with permissions of auditd related files. |
| contains 3 rules |
Verify that audit tools are owned by group root
[ref]ruleThe SUSE Linux Enterprise 15 operating system audit tools must have the proper
ownership configured to protected against unauthorized access.
Verify it by running the following command:
$ stat -c "%n %G" /usr/sbin/auditctl /usr/sbin/aureport /usr/sbin/ausearch /usr/sbin/autrace /usr/sbin/auditd /usr/sbin/augenrules /usr/sbin/audisp-syslog
/usr/sbin/auditctl root
/usr/sbin/aureport root
/usr/sbin/ausearch root
/usr/sbin/autrace root
/usr/sbin/auditd root
/usr/sbin/augenrules root
/usr/sbin/audisp-syslog root
Audit tools needed to successfully view and manipulate audit information
system activity and records. Audit tools include custom queries and report
generatorsRationale:Protecting audit information also includes identifying and protecting the
tools used to view and manipulate log data. Therefore, protecting audit
tools is necessary to prevent unauthorized operation on audit information.
Operating systems providing tools to interface with audit information
will leverage user permissions and roles identifying the user accessing the
tools and the corresponding rights the user enjoys to make access decisions
regarding the access to audit tools. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newgroup=""
if getent group "0" >/dev/null 2>&1; then
newgroup="0"
fi
if [[ -z "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/usr/sbin/auditctl" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /usr/sbin/auditctl
fi
if ! stat -c "%g %G" "/usr/sbin/aureport" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /usr/sbin/aureport
fi
if ! stat -c "%g %G" "/usr/sbin/ausearch" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /usr/sbin/ausearch
fi
if ! stat -c "%g %G" "/usr/sbin/autrace" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /usr/sbin/autrace
fi
if ! stat -c "%g %G" "/usr/sbin/auditd" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /usr/sbin/auditd
fi
if ! stat -c "%g %G" "/usr/sbin/augenrules" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /usr/sbin/augenrules
fi
if ! stat -c "%g %G" "/usr/sbin/audisp-syslog" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /usr/sbin/audisp-syslog
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_groupownership_audit_binaries_newgroup variable if represented
by gid
ansible.builtin.set_fact:
file_groupownership_audit_binaries_newgroup: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/auditctl
ansible.builtin.stat:
path: /usr/sbin/auditctl
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /usr/sbin/auditctl
ansible.builtin.file:
path: /usr/sbin/auditctl
follow: false
group: '{{ file_groupownership_audit_binaries_newgroup }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/aureport
ansible.builtin.stat:
path: /usr/sbin/aureport
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /usr/sbin/aureport
ansible.builtin.file:
path: /usr/sbin/aureport
follow: false
group: '{{ file_groupownership_audit_binaries_newgroup }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/ausearch
ansible.builtin.stat:
path: /usr/sbin/ausearch
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /usr/sbin/ausearch
ansible.builtin.file:
path: /usr/sbin/ausearch
follow: false
group: '{{ file_groupownership_audit_binaries_newgroup }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/autrace
ansible.builtin.stat:
path: /usr/sbin/autrace
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /usr/sbin/autrace
ansible.builtin.file:
path: /usr/sbin/autrace
follow: false
group: '{{ file_groupownership_audit_binaries_newgroup }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/auditd
ansible.builtin.stat:
path: /usr/sbin/auditd
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /usr/sbin/auditd
ansible.builtin.file:
path: /usr/sbin/auditd
follow: false
group: '{{ file_groupownership_audit_binaries_newgroup }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/augenrules
ansible.builtin.stat:
path: /usr/sbin/augenrules
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /usr/sbin/augenrules
ansible.builtin.file:
path: /usr/sbin/augenrules
follow: false
group: '{{ file_groupownership_audit_binaries_newgroup }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/audisp-syslog
ansible.builtin.stat:
path: /usr/sbin/audisp-syslog
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /usr/sbin/audisp-syslog
ansible.builtin.file:
path: /usr/sbin/audisp-syslog
follow: false
group: '{{ file_groupownership_audit_binaries_newgroup }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92543-8
- configure_strategy
- file_groupownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify that audit tools are owned by root
[ref]ruleThe SUSE Linux Enterprise 15 operating system audit tools must have the proper
ownership configured to protected against unauthorized access.
Verify it by running the following command:
$ stat -c "%n %U" /usr/sbin/auditctl /usr/sbin/aureport /usr/sbin/ausearch /usr/sbin/autrace /usr/sbin/auditd /usr/sbin/augenrules /usr/sbin/audisp-syslog
/usr/sbin/auditctl root
/usr/sbin/aureport root
/usr/sbin/ausearch root
/usr/sbin/autrace root
/usr/sbin/auditd root
/usr/sbin/augenrules root
/usr/sbin/audisp-syslog root
Audit tools needed to successfully view and manipulate audit information
system activity and records. Audit tools include custom queries and report
generatorsRationale:Protecting audit information also includes identifying and protecting the
tools used to view and manipulate log data. Therefore, protecting audit
tools is necessary to prevent unauthorized operation on audit information.
Operating systems providing tools to interface with audit information
will leverage user permissions and roles identifying the user accessing the
tools and the corresponding rights the user enjoys to make access decisions
regarding the access to audit tools. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/usr/sbin/auditctl" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /usr/sbin/auditctl
fi
if ! stat -c "%u %U" "/usr/sbin/aureport" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /usr/sbin/aureport
fi
if ! stat -c "%u %U" "/usr/sbin/ausearch" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /usr/sbin/ausearch
fi
if ! stat -c "%u %U" "/usr/sbin/autrace" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /usr/sbin/autrace
fi
if ! stat -c "%u %U" "/usr/sbin/auditd" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /usr/sbin/auditd
fi
if ! stat -c "%u %U" "/usr/sbin/augenrules" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /usr/sbin/augenrules
fi
if ! stat -c "%u %U" "/usr/sbin/audisp-syslog" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /usr/sbin/audisp-syslog
fi
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_ownership_audit_binaries_newown variable if represented by uid
ansible.builtin.set_fact:
file_ownership_audit_binaries_newown: '0'
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/auditctl
ansible.builtin.stat:
path: /usr/sbin/auditctl
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /usr/sbin/auditctl
ansible.builtin.file:
path: /usr/sbin/auditctl
follow: false
owner: '{{ file_ownership_audit_binaries_newown }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/aureport
ansible.builtin.stat:
path: /usr/sbin/aureport
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /usr/sbin/aureport
ansible.builtin.file:
path: /usr/sbin/aureport
follow: false
owner: '{{ file_ownership_audit_binaries_newown }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/ausearch
ansible.builtin.stat:
path: /usr/sbin/ausearch
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /usr/sbin/ausearch
ansible.builtin.file:
path: /usr/sbin/ausearch
follow: false
owner: '{{ file_ownership_audit_binaries_newown }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/autrace
ansible.builtin.stat:
path: /usr/sbin/autrace
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /usr/sbin/autrace
ansible.builtin.file:
path: /usr/sbin/autrace
follow: false
owner: '{{ file_ownership_audit_binaries_newown }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/auditd
ansible.builtin.stat:
path: /usr/sbin/auditd
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /usr/sbin/auditd
ansible.builtin.file:
path: /usr/sbin/auditd
follow: false
owner: '{{ file_ownership_audit_binaries_newown }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/augenrules
ansible.builtin.stat:
path: /usr/sbin/augenrules
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /usr/sbin/augenrules
ansible.builtin.file:
path: /usr/sbin/augenrules
follow: false
owner: '{{ file_ownership_audit_binaries_newown }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/audisp-syslog
ansible.builtin.stat:
path: /usr/sbin/audisp-syslog
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /usr/sbin/audisp-syslog
ansible.builtin.file:
path: /usr/sbin/audisp-syslog
follow: false
owner: '{{ file_ownership_audit_binaries_newown }}'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92549-5
- configure_strategy
- file_ownership_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Verify that audit tools Have Mode 0755 or less
[ref]ruleThe SUSE Linux Enterprise 15 operating system audit tools must have the proper
permissions configured to protected against unauthorized access.
Verify it by running the following command:
$ stat -c "%n %a" /usr/sbin/auditctl /usr/sbin/aureport /usr/sbin/ausearch /usr/sbin/autrace /usr/sbin/auditd /usr/sbin/augenrules /usr/sbin/audisp-syslog
/usr/sbin/auditctl 755
/usr/sbin/aureport 755
/usr/sbin/ausearch 755
/usr/sbin/autrace 755
/usr/sbin/auditd 755
/usr/sbin/augenrules 755
/usr/sbin/audisp-syslog 755
Audit tools needed to successfully view and manipulate audit information
system activity and records. Audit tools include custom queries and report
generatorsRationale:Protecting audit information also includes identifying and protecting the
tools used to view and manipulate log data. Therefore, protecting audit
tools is necessary to prevent unauthorized operation on audit information.
Operating systems providing tools to interface with audit information
will leverage user permissions and roles identifying the user accessing the
tools and the corresponding rights the user enjoys to make access decisions
regarding the access to audit tools. Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
chmod u-s,g-ws,o-wt /usr/sbin/auditctl
chmod u-s,g-ws,o-wt /usr/sbin/aureport
chmod u-s,g-ws,o-wt /usr/sbin/ausearch
chmod u-s,g-ws,o-wt /usr/sbin/autrace
chmod u-s,g-ws,o-wt /usr/sbin/auditd
chmod u-s,g-ws,o-wt /usr/sbin/augenrules
chmod u-s,g-ws,o-wt /usr/sbin/audisp-syslog
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/auditctl
ansible.builtin.stat:
path: /usr/sbin/auditctl
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-s,g-ws,o-wt on /usr/sbin/auditctl
ansible.builtin.file:
path: /usr/sbin/auditctl
mode: u-s,g-ws,o-wt
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/aureport
ansible.builtin.stat:
path: /usr/sbin/aureport
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-s,g-ws,o-wt on /usr/sbin/aureport
ansible.builtin.file:
path: /usr/sbin/aureport
mode: u-s,g-ws,o-wt
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/ausearch
ansible.builtin.stat:
path: /usr/sbin/ausearch
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-s,g-ws,o-wt on /usr/sbin/ausearch
ansible.builtin.file:
path: /usr/sbin/ausearch
mode: u-s,g-ws,o-wt
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/autrace
ansible.builtin.stat:
path: /usr/sbin/autrace
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-s,g-ws,o-wt on /usr/sbin/autrace
ansible.builtin.file:
path: /usr/sbin/autrace
mode: u-s,g-ws,o-wt
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/auditd
ansible.builtin.stat:
path: /usr/sbin/auditd
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-s,g-ws,o-wt on /usr/sbin/auditd
ansible.builtin.file:
path: /usr/sbin/auditd
mode: u-s,g-ws,o-wt
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/augenrules
ansible.builtin.stat:
path: /usr/sbin/augenrules
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-s,g-ws,o-wt on /usr/sbin/augenrules
ansible.builtin.file:
path: /usr/sbin/augenrules
mode: u-s,g-ws,o-wt
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /usr/sbin/audisp-syslog
ansible.builtin.stat:
path: /usr/sbin/audisp-syslog
register: file_exists
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-s,g-ws,o-wt on /usr/sbin/audisp-syslog
ansible.builtin.file:
path: /usr/sbin/audisp-syslog
mode: u-s,g-ws,o-wt
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- file_exists.stat is defined and file_exists.stat.exists
tags:
- CCE-92555-2
- configure_strategy
- file_permissions_audit_binaries
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
|
Ensure the libaudit1 package as a part of audit Subsystem is Installed
[ref]ruleThe libaudit1 package should be installed. Rationale:The auditd service is an access monitoring and accounting daemon, watching system calls to audit any access, in comparison with potential local access control policy such as SELinux policy. Identifiers:
CCE-92478-7 References:
CIP-004-6 R3.3, CIP-007-3 R6.5, AC-7(a), AU-7(1), AU-7(2), AU-14, AU-12(2), AU-2(a), CM-6(a), Req-10.2.1, SRG-OS-000062-GPOS-00031, SRG-OS-000037-GPOS-00015, SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019, SRG-OS-000042-GPOS-00021, SRG-OS-000051-GPOS-00024, SRG-OS-000054-GPOS-00025, SRG-OS-000122-GPOS-00063, SRG-OS-000254-GPOS-00095, SRG-OS-000255-GPOS-00096, SRG-OS-000337-GPOS-00129, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000358-GPOS-00145, SRG-OS-000365-GPOS-00152, SRG-OS-000392-GPOS-00172, SRG-OS-000475-GPOS-00220, 4.1.1.1, SLES-15-750450015 Remediation script: (show)
[[packages]]
name = "libaudit1"
version = "*"
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_libaudit1
class install_libaudit1 {
package { 'libaudit1':
ensure => 'installed',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
zypper install -y "libaudit1"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-92478-7
- NIST-800-53-AC-7(a)
- NIST-800-53-AU-12(2)
- NIST-800-53-AU-14
- NIST-800-53-AU-2(a)
- NIST-800-53-AU-7(1)
- NIST-800-53-AU-7(2)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_audit-libs_installed
- name: Ensure libaudit1 is installed
ansible.builtin.package:
name: libaudit1
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-92478-7
- NIST-800-53-AC-7(a)
- NIST-800-53-AU-12(2)
- NIST-800-53-AU-14
- NIST-800-53-AU-2(a)
- NIST-800-53-AU-7(1)
- NIST-800-53-AU-7(2)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_audit-libs_installed
|
Ensure the audit Subsystem is Installed
[ref]ruleThe audit package should be installed. Rationale:The auditd service is an access monitoring and accounting daemon, watching system calls to audit any access, in comparison with potential local access control policy such as SELinux policy. Identifiers:
CCE-85612-0 References:
164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(C), 164.310(a)(2)(iv), 164.310(d)(2)(iii), 164.312(b), CIP-004-6 R3.3, CIP-007-3 R6.5, AC-7(a), AU-7(1), AU-7(2), AU-14, AU-12(2), AU-2(a), CM-6(a), FAU_GEN.1, Req-10.1, SRG-OS-000062-GPOS-00031, SRG-OS-000037-GPOS-00015, SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019, SRG-OS-000042-GPOS-00021, SRG-OS-000051-GPOS-00024, SRG-OS-000054-GPOS-00025, SRG-OS-000122-GPOS-00063, SRG-OS-000254-GPOS-00095, SRG-OS-000255-GPOS-00096, SRG-OS-000337-GPOS-00129, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000358-GPOS-00145, SRG-OS-000365-GPOS-00152, SRG-OS-000392-GPOS-00172, SRG-OS-000475-GPOS-00220, SLES-15-030650, 4.1.1.1, R33, R73, SLES-15-750450015, 0582, 0846, 10.2.1, 10.2, SV-234964r1009639_rule Remediation script: (show)
[[packages]]
name = "audit"
version = "*"
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_audit
class install_audit {
package { 'audit':
ensure => 'installed',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base; then
zypper install -y "audit"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85612-0
- DISA-STIG-SLES-15-030650
- NIST-800-53-AC-7(a)
- NIST-800-53-AU-12(2)
- NIST-800-53-AU-14
- NIST-800-53-AU-2(a)
- NIST-800-53-AU-7(1)
- NIST-800-53-AU-7(2)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.1
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_audit_installed
- name: Ensure audit is installed
ansible.builtin.package:
name: audit
state: present
when: ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
tags:
- CCE-85612-0
- DISA-STIG-SLES-15-030650
- NIST-800-53-AC-7(a)
- NIST-800-53-AU-12(2)
- NIST-800-53-AU-14
- NIST-800-53-AU-2(a)
- NIST-800-53-AU-7(1)
- NIST-800-53-AU-7(2)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.1
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_audit_installed
|
Enable auditd Service
[ref]ruleThe auditd service is an essential userspace component of
the Linux Auditing System, as it is responsible for writing audit records to
disk.
The auditd service can be enabled with the following command:
$ sudo systemctl enable auditd.service Rationale:Without establishing what type of events occurred, it would be difficult
to establish, correlate, and investigate the events leading up to an outage or attack.
Ensuring the auditd service is active ensures audit records
generated by the kernel are appropriately recorded.
Additionally, a properly configured audit subsystem ensures that actions of
individual system users can be uniquely traced to those users so they
can be held accountable for their actions. Identifiers:
CCE-85581-7 References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.3.1, 3.3.2, 3.3.6, 164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(C), 164.310(a)(2)(iv), 164.310(d)(2)(iii), 164.312(b), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, CIP-004-6 R3.3, CIP-007-3 R6.5, AC-2(g), AU-3, AU-10, AU-2(d), AU-12(c), AU-14(1), AC-6(9), CM-6(a), SI-4(23), DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1, Req-10.1, SRG-OS-000062-GPOS-00031, SRG-OS-000037-GPOS-00015, SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019, SRG-OS-000042-GPOS-00021, SRG-OS-000051-GPOS-00024, SRG-OS-000054-GPOS-00025, SRG-OS-000122-GPOS-00063, SRG-OS-000254-GPOS-00095, SRG-OS-000255-GPOS-00096, SRG-OS-000337-GPOS-00129, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000358-GPOS-00145, SRG-OS-000365-GPOS-00152, SRG-OS-000392-GPOS-00172, SRG-OS-000475-GPOS-00220, SRG-APP-000095-CTR-000170, SRG-APP-000409-CTR-000990, SRG-APP-000508-CTR-001300, SRG-APP-000510-CTR-001310, SLES-15-030050, 4.1.1.2, R33, R73, SLES-15-750450060, 1409, 10.2.1, 10.2, SV-234904r958412_rule Remediation script: (show)
[customizations.services]
enabled = ["auditd"]
Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include enable_auditd
class enable_auditd {
service {'auditd':
enable => true,
ensure => 'running',
}
}
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q audit; }; then
SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" unmask 'auditd.service'
if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
"$SYSTEMCTL_EXEC" start 'auditd.service'
fi
"$SYSTEMCTL_EXEC" enable 'auditd.service'
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85581-7
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030050
- NIST-800-171-3.3.1
- NIST-800-171-3.3.2
- NIST-800-171-3.3.6
- NIST-800-53-AC-2(g)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-10
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-14(1)
- NIST-800-53-AU-2(d)
- NIST-800-53-AU-3
- NIST-800-53-CM-6(a)
- NIST-800-53-SI-4(23)
- PCI-DSS-Req-10.1
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_auditd_enabled
- name: Enable auditd Service - Enable service auditd
block:
- name: Gather the package facts
ansible.builtin.package_facts:
manager: auto
- name: Enable auditd Service - Enable Service auditd
ansible.builtin.systemd:
name: auditd
enabled: true
state: started
masked: false
when:
- '"audit" in ansible_facts.packages'
tags:
- CCE-85581-7
- CJIS-5.4.1.1
- DISA-STIG-SLES-15-030050
- NIST-800-171-3.3.1
- NIST-800-171-3.3.2
- NIST-800-171-3.3.6
- NIST-800-53-AC-2(g)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-10
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-14(1)
- NIST-800-53-AU-2(d)
- NIST-800-53-AU-3
- NIST-800-53-CM-6(a)
- NIST-800-53-SI-4(23)
- PCI-DSS-Req-10.1
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_auditd_enabled
- special_service_block
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"audit" in ansible_facts.packages'
|
Enable Auditing for Processes Which Start Prior to the Audit Daemon
[ref]ruleTo ensure all processes can be audited, even those which start
prior to the audit daemon, add the argument audit=1 to the default
GRUB 2 command line for the Linux operating system.
Configure the default Grub2 kernel command line to contain audit=1 as follows:
# grub2-editenv - set "$(grub2-editenv - list | grep kernelopts) audit=1" Rationale:Each process on the system carries an "auditable" flag which indicates whether
its activities can be audited. Although auditd takes care of enabling
this for all processes which launch after it does, adding the kernel argument
ensures it is set for every process during boot. Identifiers:
CCE-85832-4 References:
1, 11, 12, 13, 14, 15, 16, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.02, DSS05.03, DSS05.04, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.3.1, 164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(C), 164.310(a)(2)(iv), 164.310(d)(2)(iii), 164.312(b), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AC-17(1), AU-14(1), AU-10, CM-6(a), IR-5(1), DE.AE-3, DE.AE-5, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1, Req-10.3, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000473-GPOS-00218, SRG-OS-000254-GPOS-00095, 4.1.1.3, SLES-15-750450030, 10.7.2, 10.7 Remediation script: (show)
[customizations.kernel]
append = "audit=1"
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q grub2; }; then
if { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
KARGS_DIR="/usr/lib/bootc/kargs.d/"
if grep -q -E "audit" "$KARGS_DIR/*.toml" ; then
sed -i -E "s/^(\s*kargs\s*=\s*\[.*)\"audit=[^\"]*\"(.*]\s*)/\1\"audit=1\"\2/" "$KARGS_DIR/*.toml"
else
echo "kargs = [\"audit=1\"]" >> "$KARGS_DIR/10-audit.toml"
fi
else
# Correct the form of default kernel command line in GRUB
if grep -q '^\s*GRUB_CMDLINE_LINUX=.*audit=.*"' '/etc/default/grub' ; then
# modify the GRUB command-line if an audit= arg already exists
sed -i "s/\(^\s*GRUB_CMDLINE_LINUX=\".*\)audit=[^[:space:]]\+\(.*\"\)/\1audit=1\2/" '/etc/default/grub'
# Add to already existing GRUB_CMDLINE_LINUX parameters
elif grep -q '^\s*GRUB_CMDLINE_LINUX=' '/etc/default/grub' ; then
# no audit=arg is present, append it
sed -i "s/\(^\s*GRUB_CMDLINE_LINUX=\".*\)\"/\1 audit=1\"/" '/etc/default/grub'
# Add GRUB_CMDLINE_LINUX parameters line
else
echo "GRUB_CMDLINE_LINUX=\"audit=1\"" >> '/etc/default/grub'
fi
grub2-mkconfig -o /boot/grub2/grub.cfg
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | medium |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-85832-4
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-17(1)
- NIST-800-53-AU-10
- NIST-800-53-AU-14(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-IR-5(1)
- PCI-DSS-Req-10.3
- PCI-DSSv4-10.7
- PCI-DSSv4-10.7.2
- grub2_audit_argument
- low_disruption
- low_severity
- medium_complexity
- reboot_required
- restrict_strategy
- name: Check audit argument exists
ansible.builtin.command: grep '^\s*GRUB_CMDLINE_LINUX=.*audit=' /etc/default/grub
check_mode: false
failed_when: false
changed_when: false
register: argcheck
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"grub2" in ansible_facts.packages'
tags:
- CCE-85832-4
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-17(1)
- NIST-800-53-AU-10
- NIST-800-53-AU-14(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-IR-5(1)
- PCI-DSS-Req-10.3
- PCI-DSSv4-10.7
- PCI-DSSv4-10.7.2
- grub2_audit_argument
- low_disruption
- low_severity
- medium_complexity
- reboot_required
- restrict_strategy
- name: Check audit argument exists
ansible.builtin.command: grep '^\s*GRUB_CMDLINE_LINUX=' /etc/default/grub
check_mode: false
failed_when: false
changed_when: false
register: linecheck
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"grub2" in ansible_facts.packages'
tags:
- CCE-85832-4
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-17(1)
- NIST-800-53-AU-10
- NIST-800-53-AU-14(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-IR-5(1)
- PCI-DSS-Req-10.3
- PCI-DSSv4-10.7
- PCI-DSSv4-10.7.2
- grub2_audit_argument
- low_disruption
- low_severity
- medium_complexity
- reboot_required
- restrict_strategy
- name: Add audit argument
ansible.builtin.lineinfile:
line: GRUB_CMDLINE_LINUX="audit=1 "
state: present
dest: /etc/default/grub
create: true
mode: '0644'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"grub2" in ansible_facts.packages'
- argcheck is not skipped and linecheck is not skipped and argcheck.rc != 0 and
linecheck.rc != 0
tags:
- CCE-85832-4
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-17(1)
- NIST-800-53-AU-10
- NIST-800-53-AU-14(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-IR-5(1)
- PCI-DSS-Req-10.3
- PCI-DSSv4-10.7
- PCI-DSSv4-10.7.2
- grub2_audit_argument
- low_disruption
- low_severity
- medium_complexity
- reboot_required
- restrict_strategy
- name: Replace existing audit argument
ansible.builtin.replace:
path: /etc/default/grub
regexp: audit=[a-zA-Z0-9,]+
replace: audit=1
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"grub2" in ansible_facts.packages'
- argcheck is not skipped and linecheck is not skipped and argcheck.rc == 0 and
linecheck.rc == 0
tags:
- CCE-85832-4
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-17(1)
- NIST-800-53-AU-10
- NIST-800-53-AU-14(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-IR-5(1)
- PCI-DSS-Req-10.3
- PCI-DSSv4-10.7
- PCI-DSSv4-10.7.2
- grub2_audit_argument
- low_disruption
- low_severity
- medium_complexity
- reboot_required
- restrict_strategy
- name: Add audit argument
ansible.builtin.replace:
path: /etc/default/grub
regexp: (^\s*GRUB_CMDLINE_LINUX=.*)"
replace: \1 audit=1"
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"grub2" in ansible_facts.packages'
- argcheck is not skipped and linecheck is not skipped and argcheck.rc != 0 and
linecheck.rc == 0
tags:
- CCE-85832-4
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-17(1)
- NIST-800-53-AU-10
- NIST-800-53-AU-14(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-IR-5(1)
- PCI-DSS-Req-10.3
- PCI-DSSv4-10.7
- PCI-DSSv4-10.7.2
- grub2_audit_argument
- low_disruption
- low_severity
- medium_complexity
- reboot_required
- restrict_strategy
- name: Update grub defaults and the bootloader menu
ansible.builtin.command: /usr/sbin/grub2-mkconfig -o /boot/grub2/grub.cfg
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"grub2" in ansible_facts.packages'
tags:
- CCE-85832-4
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-53-AC-17(1)
- NIST-800-53-AU-10
- NIST-800-53-AU-14(1)
- NIST-800-53-CM-6(a)
- NIST-800-53-IR-5(1)
- PCI-DSS-Req-10.3
- PCI-DSSv4-10.7
- PCI-DSSv4-10.7.2
- grub2_audit_argument
- low_disruption
- low_severity
- medium_complexity
- reboot_required
- restrict_strategy
|
Extend Audit Backlog Limit for the Audit Daemon
[ref]ruleTo improve the kernel capacity to queue all log events, even those which occurred
prior to the audit daemon, add the argument audit_backlog_limit=8192 to the default
GRUB 2 command line for the Linux operating system.
Configure the default Grub2 kernel command line to contain audit_backlog_limit=8192 as follows:
# grub2-editenv - set "$(grub2-editenv - list | grep kernelopts) audit_backlog_limit=8192" Rationale:audit_backlog_limit sets the queue length for audit events awaiting transfer
to the audit daemon. Until the audit daemon is up and running, all log messages
are stored in this queue. If the queue is overrun during boot process, the action
defined by audit failure flag is taken. Identifiers:
CCE-91374-9 References:
CM-6(a), FAU_STG.1, FAU_STG.3, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000254-GPOS-00095, SRG-OS-000341-GPOS-00132, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, 4.1.2.4, SLES-15-750450045, 10.7.2, 10.7 Remediation script: (show)
[customizations.kernel]
append = "audit_backlog_limit=8192"
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-default || rpm --quiet -q kernel-default-base && { rpm --quiet -q grub2; }; then
var_audit_backlog_limit='8192'
if { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
KARGS_DIR="/usr/lib/bootc/kargs.d/"
if grep -q -E "audit_backlog_limit" "$KARGS_DIR/*.toml" ; then
sed -i -E "s/^(\s*kargs\s*=\s*\[.*)\"audit_backlog_limit=[^\"]*\"(.*]\s*)/\1\"audit_backlog_limit=$var_audit_backlog_limit\"\2/" "$KARGS_DIR/*.toml"
else
echo "kargs = [\"audit_backlog_limit=$var_audit_backlog_limit\"]" >> "$KARGS_DIR/10-audit_backlog_limit.toml"
fi
else
# Correct the form of default kernel command line in GRUB
if grep -q '^\s*GRUB_CMDLINE_LINUX=.*audit_backlog_limit=.*"' '/etc/default/grub' ; then
# modify the GRUB command-line if an audit_backlog_limit= arg already exists
sed -i "s/\(^\s*GRUB_CMDLINE_LINUX=\".*\)audit_backlog_limit=[^[:space:]]\+\(.*\"\)/\1audit_backlog_limit=$var_audit_backlog_limit\2/" '/etc/default/grub'
# Add to already existing GRUB_CMDLINE_LINUX parameters
elif grep -q '^\s*GRUB_CMDLINE_LINUX=' '/etc/default/grub' ; then
# no audit_backlog_limit=arg is present, append it
sed -i "s/\(^\s*GRUB_CMDLINE_LINUX=\".*\)\"/\1 audit_backlog_limit=$var_audit_backlog_limit\"/" '/etc/default/grub'
# Add GRUB_CMDLINE_LINUX parameters line
else
echo "GRUB_CMDLINE_LINUX=\"audit_backlog_limit=$var_audit_backlog_limit\"" >> '/etc/default/grub'
fi
grub2-mkconfig -o /boot/grub2/grub.cfg
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation Ansible snippet: (show)
| Complexity: | medium |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-91374-9
- NIST-800-53-CM-6(a)
- PCI-DSSv4-10.7
- PCI-DSSv4-10.7.2
- grub2_audit_backlog_limit_argument
- low_disruption
- low_severity
- medium_complexity
- reboot_required
- restrict_strategy
- name: XCCDF Value var_audit_backlog_limit # promote to variable
set_fact:
var_audit_backlog_limit: !!str 8192
tags:
- always
- name: Check audit_backlog_limit argument exists
ansible.builtin.command: grep '^\s*GRUB_CMDLINE_LINUX=.*audit_backlog_limit=' /etc/default/grub
check_mode: false
failed_when: false
changed_when: false
register: argcheck
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"grub2" in ansible_facts.packages'
tags:
- CCE-91374-9
- NIST-800-53-CM-6(a)
- PCI-DSSv4-10.7
- PCI-DSSv4-10.7.2
- grub2_audit_backlog_limit_argument
- low_disruption
- low_severity
- medium_complexity
- reboot_required
- restrict_strategy
- name: Check audit_backlog_limit argument exists
ansible.builtin.command: grep '^\s*GRUB_CMDLINE_LINUX=' /etc/default/grub
check_mode: false
failed_when: false
changed_when: false
register: linecheck
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"grub2" in ansible_facts.packages'
tags:
- CCE-91374-9
- NIST-800-53-CM-6(a)
- PCI-DSSv4-10.7
- PCI-DSSv4-10.7.2
- grub2_audit_backlog_limit_argument
- low_disruption
- low_severity
- medium_complexity
- reboot_required
- restrict_strategy
- name: Add audit_backlog_limit argument
ansible.builtin.lineinfile:
line: GRUB_CMDLINE_LINUX="audit_backlog_limit={{ var_audit_backlog_limit }} "
state: present
dest: /etc/default/grub
create: true
mode: '0644'
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"grub2" in ansible_facts.packages'
- argcheck is not skipped and linecheck is not skipped and argcheck.rc != 0 and
linecheck.rc != 0
tags:
- CCE-91374-9
- NIST-800-53-CM-6(a)
- PCI-DSSv4-10.7
- PCI-DSSv4-10.7.2
- grub2_audit_backlog_limit_argument
- low_disruption
- low_severity
- medium_complexity
- reboot_required
- restrict_strategy
- name: Replace existing audit_backlog_limit argument
ansible.builtin.replace:
path: /etc/default/grub
regexp: audit_backlog_limit=[a-zA-Z0-9,]+
replace: audit_backlog_limit={{ var_audit_backlog_limit }}
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"grub2" in ansible_facts.packages'
- argcheck is not skipped and linecheck is not skipped and argcheck.rc == 0 and
linecheck.rc == 0
tags:
- CCE-91374-9
- NIST-800-53-CM-6(a)
- PCI-DSSv4-10.7
- PCI-DSSv4-10.7.2
- grub2_audit_backlog_limit_argument
- low_disruption
- low_severity
- medium_complexity
- reboot_required
- restrict_strategy
- name: Add audit_backlog_limit argument
ansible.builtin.replace:
path: /etc/default/grub
regexp: (^\s*GRUB_CMDLINE_LINUX=.*)"
replace: \1 audit_backlog_limit={{ var_audit_backlog_limit }}"
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"grub2" in ansible_facts.packages'
- argcheck is not skipped and linecheck is not skipped and argcheck.rc != 0 and
linecheck.rc == 0
tags:
- CCE-91374-9
- NIST-800-53-CM-6(a)
- PCI-DSSv4-10.7
- PCI-DSSv4-10.7.2
- grub2_audit_backlog_limit_argument
- low_disruption
- low_severity
- medium_complexity
- reboot_required
- restrict_strategy
- name: Update grub defaults and the bootloader menu
ansible.builtin.command: /usr/sbin/grub2-mkconfig -o /boot/grub2/grub.cfg
when:
- ("kernel-default" in ansible_facts.packages or "kernel-default-base" in ansible_facts.packages)
- '"grub2" in ansible_facts.packages'
tags:
- CCE-91374-9
- NIST-800-53-CM-6(a)
- PCI-DSSv4-10.7
- PCI-DSSv4-10.7.2
- grub2_audit_backlog_limit_argument
- low_disruption
- low_severity
- medium_complexity
- reboot_required
- restrict_strategy
|