| contains 313 rules |
System Settings
[ref]groupContains rules that check correct system settings. |
| contains 156 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 11 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 2 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 2 rules |
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 2 rules |
Install AIDE
[ref]ruleThe aide package can be installed with the following command:
$ sudo dnf install aide Rationale:The AIDE package must be installed if it is to be available for integrity checking. 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, R76, R79, 1034, 1288, 1341, 1417, 11.5.2 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_aide
class install_aide {
package { 'aide':
ensure => 'installed',
}
}
Remediation script: (show)
[[packages]]
name = "aide"
version = "*"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CJIS-5.10.1.3
- 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" in ansible_facts.packages'
tags:
- CJIS-5.10.1.3
- 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
|
Configure Periodic Execution of AIDE
[ref]ruleAt a minimum, AIDE should be configured to run a weekly scan.
To implement a daily execution of AIDE at 4:05am using cron, add the following line to /etc/crontab:
05 4 * * * root /usr/sbin/aide --check
To implement a weekly execution of AIDE at 4:05am using cron, add the following line to /etc/crontab:
05 4 * * 0 root /usr/sbin/aide --check
AIDE can be executed periodically through other means; this is merely one example.
The usage of cron's special time codes, such as @daily and
@weekly is acceptable.Rationale:By default, AIDE does not install itself for periodic execution. Periodically
running AIDE is necessary to reveal unexpected changes in installed files.
Unauthorized changes to the baseline configuration could make the system vulnerable
to various attacks or allow unauthorized access to the operating system. Changes to
operating system configurations can have unintended side effects, some of which may
be relevant to security.
Detecting such changes and providing an automated response can help avoid unintended,
negative consequences that could ultimately affect the security state of the operating
system. The operating system's Information Management Officer (IMO)/Information System
Security Officer (ISSO) and System Administrators (SAs) must be notified via email and/or
monitoring system trap when there is an unauthorized modification of a configuration item. 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-7, SI-7(1), 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-000363-GPOS-00150, SRG-OS-000446-GPOS-00200, SRG-OS-000447-GPOS-00201, R76, 11.5.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CJIS-5.10.1.3
- NIST-800-53-CM-6(a)
- NIST-800-53-SI-7
- NIST-800-53-SI-7(1)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_periodic_cron_checking
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure Periodic Execution of AIDE - Ensure AIDE is installed
ansible.builtin.package:
name: aide
state: present
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.3
- NIST-800-53-CM-6(a)
- NIST-800-53-SI-7
- NIST-800-53-SI-7(1)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_periodic_cron_checking
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure Periodic Execution of AIDE - Install cron
ansible.builtin.package:
name: cronie
state: present
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.3
- NIST-800-53-CM-6(a)
- NIST-800-53-SI-7
- NIST-800-53-SI-7(1)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_periodic_cron_checking
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure Periodic Execution of AIDE - Gather List of Installed Packages
ansible.builtin.package_facts:
manager: auto
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.3
- NIST-800-53-CM-6(a)
- NIST-800-53-SI-7
- NIST-800-53-SI-7(1)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_periodic_cron_checking
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Configure Periodic Execution of AIDE - Setup Cron Tab
ansible.builtin.cron:
name: run AIDE check
minute: 5
hour: 4
user: root
job: /usr/sbin/aide --check
register: crontab_check
when:
- '"kernel" in ansible_facts.packages'
- '''cronie'' in ansible_facts.packages'
tags:
- CJIS-5.10.1.3
- NIST-800-53-CM-6(a)
- NIST-800-53-SI-7
- NIST-800-53-SI-7(1)
- PCI-DSS-Req-11.5
- PCI-DSSv4-11.5.2
- aide_periodic_cron_checking
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
|
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 2 rules |
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 /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. 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 |
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 5 rules |
Install sudo Package
[ref]ruleThe sudo package can be installed with the following command:
$ sudo dnf 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 Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_sudo
class install_sudo {
package { 'sudo':
ensure => 'installed',
}
}
Remediation script: (show)
[[packages]]
name = "sudo"
version = "*"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
- '"sudo" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { 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.*$' /etc/sudoers; then
# sudoers file doesn't define Option use_pty
echo "Defaults use_pty" >> /etc/sudoers
fi
# Check validity of sudoers and cleanup bak
if /usr/sbin/visudo -qcf /etc/sudoers; then
rm -f /etc/sudoers.bak
else
echo "Fail to validate remediated /etc/sudoers, reverting to original file."
mv /etc/sudoers.bak /etc/sudoers
false
fi
else
echo "Skipping remediation, /etc/sudoers failed to validate"
false
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Ensure Sudo Logfile Exists - sudo logfile
[ref]ruleA custom log sudo file can be configured with the 'logfile' tag. This rule configures
a sudo custom logfile at the default location suggested by CIS, which uses
/var/log/sudo.log. Rationale:A sudo log file simplifies auditing of sudo commands. Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- restrict_strategy
- sudo_custom_logfile
- name: XCCDF Value var_sudo_logfile # promote to variable
set_fact:
var_sudo_logfile: !!str /var/log/sudo.log
tags:
- always
- name: Ensure logfile is enabled with the appropriate value in /etc/sudoers
ansible.builtin.lineinfile:
path: /etc/sudoers
regexp: ^[\s]*Defaults\s(.*)\blogfile=[-]?.+\b(.*)$
line: Defaults \1logfile={{ var_sudo_logfile }}\2
validate: /usr/sbin/visudo -cf %s
backrefs: true
register: edit_sudoers_logfile_option
when:
- '"kernel" in ansible_facts.packages'
- '"sudo" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- '"sudo" in ansible_facts.packages'
- edit_sudoers_logfile_option is defined and not edit_sudoers_logfile_option.changed
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { 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
|
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. 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, 1546, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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.*$)
replace: '# \g<1>'
path: '{{ item.path }}'
validate: /usr/sbin/visudo -cf %s
with_items:
- path: /etc/sudoers
- '{{ sudoers.files }}'
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-11
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sudo_require_authentication
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
for f in /etc/sudoers /etc/sudoers.d/* ; do
if [ ! -e "$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
|
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. |
Updating Software
[ref]groupThe dnf 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.
TencentOS Server 4 systems contain an installed software catalog called
the RPM database, which records metadata of installed packages. Consistently using
dnf or the graphical Software Update for all software installation
allows for insight into the current inventory of installed software on the system.
|
| contains 2 rules |
Ensure gpgcheck Enabled In Main dnf Configuration
[ref]ruleThe gpgcheck option controls whether
RPM packages' signatures are always checked prior to installation.
To configure dnf to check package signatures before installing
them, ensure the following line appears in /etc/yum.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). 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, R59, 1493, 6.3.3, 6.3 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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
- 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/yum.conf
section: main
option: gpgcheck
value: 1
no_extra_spaces: true
create: false
when: '"dnf" in ansible_facts.packages'
tags:
- 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
- configure_strategy
- ensure_gpgcheck_globally_activated
- high_severity
- low_complexity
- medium_disruption
- no_reboot_needed
|
Ensure gpgcheck Enabled for All dnf Package Repositories
[ref]ruleTo ensure signature checking is not disabled for
any repos, remove any lines from files in /etc/yum.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)." 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, R59, 1493, 6.3.3, 6.3 |
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
TencentOS Server 4. |
| contains 48 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 12 rules |
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. 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 |
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | unknown |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- banner_etc_issue_net
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- unknown_strategy
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. |
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 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:
- configure_strategy
- file_groupowner_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/issue
ansible.builtin.stat:
path: /etc/issue
register: file_exists
tags:
- configure_strategy
- file_groupowner_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure group owner on /etc/issue
ansible.builtin.file:
path: /etc/issue
follow: false
group: '{{ file_groupowner_etc_issue_newgroup }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- configure_strategy
- file_groupowner_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
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 "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/issue" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/issue
fi
fi
|
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 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:
- 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:
- 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:
- 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
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
|
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 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:
- 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:
- 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:
- configure_strategy
- file_groupowner_etc_motd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
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
|
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 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:
- configure_strategy
- file_owner_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Test for existence /etc/issue
ansible.builtin.stat:
path: /etc/issue
register: file_exists
tags:
- configure_strategy
- file_owner_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on /etc/issue
ansible.builtin.file:
path: /etc/issue
follow: false
owner: '{{ file_owner_etc_issue_newown }}'
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- configure_strategy
- file_owner_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
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 "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
if ! stat -c "%u %U" "/etc/issue" | grep -E -w -q "0"; then
chown --no-dereference "$newown" /etc/issue
fi
fi
|
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 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:
- 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:
- 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:
- 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
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
|
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 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:
- 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:
- 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:
- configure_strategy
- file_owner_etc_motd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
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
|
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 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:
- 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:
- configure_strategy
- file_permissions_etc_issue
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/issue
|
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 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:
- 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:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/issue.net
|
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 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:
- 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:
- configure_strategy
- file_permissions_etc_motd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/motd
|
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 2 rules |
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. 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, 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 && { 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
AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
for pam_file in "${AUTH_FILES[@]}"
do
if ! grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+(preauth silent|authfail).*$' "$pam_file" ; then
sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix\.so.*/i auth required pam_faillock.so preauth silent' "$pam_file"
sed -i --follow-symlinks '/^auth.*required.*pam_deny\.so.*/i auth required pam_faillock.so authfail' "$pam_file"
sed -i --follow-symlinks '/^account.*required.*pam_unix\.so.*/i account required pam_faillock.so' "$pam_file"
fi
sed -Ei 's/(auth.*)(\[default=die\])(.*pam_faillock\.so)/\1required \3/g' "$pam_file"
done
fi
AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
SKIP_FAILLOCK_CHECK=false
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
|
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 300 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. 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, 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 && { rpm --quiet -q pam; }; then
var_accounts_passwords_pam_faillock_unlock_time='300'
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
AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
for pam_file in "${AUTH_FILES[@]}"
do
if ! grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+(preauth silent|authfail).*$' "$pam_file" ; then
sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix\.so.*/i auth required pam_faillock.so preauth silent' "$pam_file"
sed -i --follow-symlinks '/^auth.*required.*pam_deny\.so.*/i auth required pam_faillock.so authfail' "$pam_file"
sed -i --follow-symlinks '/^account.*required.*pam_unix\.so.*/i account required pam_faillock.so' "$pam_file"
fi
sed -Ei 's/(auth.*)(\[default=die\])(.*pam_faillock\.so)/\1required \3/g' "$pam_file"
done
fi
AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
SKIP_FAILLOCK_CHECK=false
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 8 rules |
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 8 rules |
Ensure PAM Enforces Password Requirements - Minimum Digit Characters
[ref]ruleThe pam_pwquality 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_pwquality will grant +1 additional
length credit for each digit. Modify the dcredit setting in
/etc/security/pwquality.conf to require the use of a digit in passwords. Rationale:Use of a complex password helps to increase the time and resources required
to compromise the password. Password complexity, or strength, is a measure of
the effectiveness of a password in resisting attempts at guessing and brute-force
attacks.
Password complexity is one factor of several that determines how long it takes
to crack a password. The more complex the password, the greater the number of
possible combinations that need to be tested before the password is compromised.
Requiring digits makes password guessing attacks more difficult by ensuring a larger
search space. References:
1, 12, 15, 16, 5, 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-000071-GPOS-00039, R31, 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, 8.3.6, 8.3 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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_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 0
tags:
- always
- name: Ensure PAM Enforces Password Requirements - Minimum Digit Characters - Ensure
PAM variable dcredit is set accordingly
ansible.builtin.lineinfile:
create: true
dest: /etc/security/pwquality.conf
regexp: ^#?\s*dcredit
line: dcredit = {{ var_password_pam_dcredit }}
when:
- '"kernel" in ansible_facts.packages'
- '"libpwquality" in ansible_facts.packages'
tags:
- 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_dcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { rpm --quiet -q libpwquality; }; then
var_password_pam_dcredit='0'
# 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=$(sed 's/[\^=\$,;+]*//g' <<< "^dcredit")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_dcredit"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^dcredit\\>" "/etc/security/pwquality.conf"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^dcredit\\>.*/$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
printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Ensure PAM Enforces Password Requirements - Enforce for root User
[ref]ruleThe pam_pwquality module's enforce_for_root parameter controls requirements for
enforcing password complexity for the root user. Enable the enforce_for_root
setting in /etc/security/pwquality.conf to require the root user
to use complex passwords. Rationale:Use of a complex password helps to increase the time and resources required to compromise
the password. Password complexity, or strength, is a measure of the effectiveness of a
password in resisting attempts at guessing and brute-force attacks.
Password complexity is one factor of several that determines how long it takes to crack a
password. The more complex the password, the greater the number of possible combinations
that need to be tested before the password is compromised. References:
IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), SRG-OS-000072-GPOS-00040, SRG-OS-000071-GPOS-00039, SRG-OS-000070-GPOS-00038, SRG-OS-000266-GPOS-00101, SRG-OS-000078-GPOS-00046, SRG-OS-000480-GPOS-00225, SRG-OS-000069-GPOS-00037 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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)
- accounts_password_pam_enforce_root
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure PAM Enforces Password Requirements - Enforce for root User
ansible.builtin.lineinfile:
path: /etc/security/pwquality.conf
create: true
regexp: ''
line: enforce_for_root
state: present
when:
- '"kernel" in ansible_facts.packages'
- '"libpwquality" in ansible_facts.packages'
tags:
- 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)
- accounts_password_pam_enforce_root
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { rpm --quiet -q libpwquality; }; then
if [ -e "/etc/security/pwquality.conf" ] ; then
LC_ALL=C sed -i "/^\s*enforce_for_root/Id" "/etc/security/pwquality.conf"
else
touch "/etc/security/pwquality.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/security/pwquality.conf"
cp "/etc/security/pwquality.conf" "/etc/security/pwquality.conf.bak"
# Insert at the end of the file
printf '%s\n' "enforce_for_root" >> "/etc/security/pwquality.conf"
# Clean up after ourselves.
rm "/etc/security/pwquality.conf.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters
[ref]ruleThe pam_pwquality 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_pwquality will grant +1 additional
length credit for each lowercase character. Modify the lcredit setting in
/etc/security/pwquality.conf to require the use of a lowercase character in passwords. Rationale:Use of a complex password helps to increase the time and resources required
to compromise the password. Password complexity, or strength, is a measure of
the effectiveness of a password in resisting attempts at guessing and brute-force
attacks.
Password complexity is one factor of several that determines how long it takes
to crack a password. The more complex the password, the greater the number of
possible combinations that need to be tested before the password is compromised.
Requiring a minimum number of lowercase characters makes password guessing attacks
more difficult by ensuring a larger search space. References:
1, 12, 15, 16, 5, 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-000070-GPOS-00038, R31, 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, 8.3.6, 8.3 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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_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 0
tags:
- always
- name: Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters -
Ensure PAM variable lcredit is set accordingly
ansible.builtin.lineinfile:
create: true
dest: /etc/security/pwquality.conf
regexp: ^#?\s*lcredit
line: lcredit = {{ var_password_pam_lcredit }}
when:
- '"kernel" in ansible_facts.packages'
- '"libpwquality" in ansible_facts.packages'
tags:
- 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_lcredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { rpm --quiet -q libpwquality; }; then
var_password_pam_lcredit='0'
# 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=$(sed 's/[\^=\$,;+]*//g' <<< "^lcredit")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_lcredit"
# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^lcredit\\>" "/etc/security/pwquality.conf"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^lcredit\\>.*/$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
printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Ensure PAM Enforces Password Requirements - Minimum Different Categories
[ref]ruleThe pam_pwquality module's minclass parameter controls
requirements for usage of different character classes, or types, of character
that must exist in a password before it is considered valid. For example,
setting this value to three (3) requires that any password must have characters
from at least three different categories in order to be approved. The default
value is zero (0), meaning there are no required classes. There are four
categories available:
* Upper-case characters
* Lower-case characters
* Digits
* Special characters (for example, punctuation)
Modify the minclass setting in /etc/security/pwquality.conf entry
to require 3
differing categories of characters when changing passwords.Rationale:Use of a complex password helps to increase the time and resources required to compromise the password.
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts
at guessing and brute-force attacks.
Password complexity is one factor of several that determines how long it takes to crack a password. The
more complex the password, the greater the number of possible combinations that need to be tested before
the password is compromised.
Requiring a minimum number of character categories makes password guessing attacks more difficult
by ensuring a larger search space. References:
1, 12, 15, 16, 5, 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, SRG-OS-000072-GPOS-00040, R68, 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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)
- accounts_password_pam_minclass
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_password_pam_minclass # promote to variable
set_fact:
var_password_pam_minclass: !!str 3
tags:
- always
- name: Ensure PAM Enforces Password Requirements - Minimum Different Categories -
Ensure PAM variable minclass is set accordingly
ansible.builtin.lineinfile:
create: true
dest: /etc/security/pwquality.conf
regexp: ^#?\s*minclass
line: minclass = {{ var_password_pam_minclass }}
when:
- '"kernel" in ansible_facts.packages'
- '"libpwquality" in ansible_facts.packages'
tags:
- 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)
- accounts_password_pam_minclass
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { rpm --quiet -q libpwquality; }; then
var_password_pam_minclass='3'
# 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' <<< "^minclass")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_minclass"
# 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 "^minclass\\>" "/etc/security/pwquality.conf"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^minclass\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
else
if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
fi
printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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=8
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. 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, R31, R68, 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, 8.3.6, 8.3 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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 8
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" in ansible_facts.packages'
- '"libpwquality" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { rpm --quiet -q libpwquality; }; then
var_password_pam_minlen='8'
# 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
printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Ensure PAM Enforces Password Requirements - Minimum Special Characters
[ref]ruleThe pam_pwquality 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_pwquality will grant +1
additional length credit for each special character. Modify the ocredit setting
in /etc/security/pwquality.conf to equal 0
to require use of a special character in passwords. Rationale:Use of a complex password helps to increase the time and resources required
to compromise the password. Password complexity, or strength, is a measure of
the effectiveness of a password in resisting attempts at guessing and brute-force
attacks.
Password complexity is one factor of several that determines how long it takes
to crack a password. The more complex the password, the greater the number of
possible combinations that need to be tested before the password is compromised.
Requiring a minimum number of special characters makes password guessing attacks
more difficult by ensuring a larger search space. References:
1, 12, 15, 16, 5, 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, SRG-OS-000266-GPOS-00101, R31, 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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)
- 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 0
tags:
- always
- name: Ensure PAM Enforces Password Requirements - Minimum Special Characters - Ensure
PAM variable ocredit is set accordingly
ansible.builtin.lineinfile:
create: true
dest: /etc/security/pwquality.conf
regexp: ^#?\s*ocredit
line: ocredit = {{ var_password_pam_ocredit }}
when:
- '"kernel" in ansible_facts.packages'
- '"libpwquality" in ansible_facts.packages'
tags:
- 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)
- accounts_password_pam_ocredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { rpm --quiet -q libpwquality; }; then
var_password_pam_ocredit='0'
# 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' <<< "^ocredit")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_ocredit"
# 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 "^ocredit\\>" "/etc/security/pwquality.conf"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^ocredit\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
else
if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
fi
printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted Per-Session
[ref]ruleTo configure the number of retry prompts that are permitted per-session:
Edit the pam_pwquality.so statement in
/etc/pam.d/system-auth to show
retry=3, or a lower value if site
policy is more restrictive. The profile requirement is a maximum of retry=3 prompts
per session. Rationale:Setting the password retry prompts that are permitted on a per-session basis to a low value
requires some software, such as SSH, to re-connect. This can slow down and
draw additional attention to some types of password-guessing attacks. Note that this
is different from account lockout, which is provided by the pam_faillock module. References:
1, 11, 12, 15, 16, 3, 5, 9, 5.5.3, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 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, 4.3.4.3.2, 4.3.4.3.3, 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 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.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, CM-6(a), AC-7(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, PR.IP-1, SRG-OS-000069-GPOS-00037, SRG-OS-000480-GPOS-00227, R68 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { rpm --quiet -q libpwquality; }; then
var_password_pam_retry='3'
if [ -e "/etc/pam.d/system-auth" ] ; then
PAM_FILE_PATH="/etc/pam.d/system-auth"
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 "/etc/pam.d/system-auth")
PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"
authselect apply-changes -b
fi
if ! grep -qP "^\s*password\s+requisite\s+pam_pwquality.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_pwquality.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
# The control is updated only if one single line matches.
sed -i -E --follow-symlinks "s/^(\s*password\s+).*(\bpam_pwquality.so.*)/\1requisite \2/" "$PAM_FILE_PATH"
else
LAST_MATCH_LINE=$(grep -nP "^\s*account" "$PAM_FILE_PATH" | tail -n 1 | cut -d: -f 1)
if [ ! -z $LAST_MATCH_LINE ]; then
sed -i --follow-symlinks $LAST_MATCH_LINE" a password requisite pam_pwquality.so" "$PAM_FILE_PATH"
else
echo "password requisite pam_pwquality.so" >> "$PAM_FILE_PATH"
fi
fi
fi
# Check the option
if ! grep -qP "^\s*password\s+requisite\s+pam_pwquality.so\s*.*\sretry\b" "$PAM_FILE_PATH"; then
sed -i -E --follow-symlinks "/\s*password\s+requisite\s+pam_pwquality.so.*/ s/$/ retry=$var_password_pam_retry/" "$PAM_FILE_PATH"
else
sed -i -E --follow-symlinks "s/(\s*password\s+requisite\s+pam_pwquality.so\s+.*)(retry=)[[:alnum:]]*\s*(.*)/\1\2$var_password_pam_retry \3/" "$PAM_FILE_PATH"
fi
if [ -f /usr/bin/authselect ]; then
authselect apply-changes -b
fi
else
echo "/etc/pam.d/system-auth was not found" >&2
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters
[ref]ruleThe pam_pwquality 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_pwquality will grant +1 additional
length credit for each uppercase character. Modify the ucredit setting in
/etc/security/pwquality.conf to require the use of an uppercase character in passwords. Rationale:Use of a complex password helps to increase the time and resources required to compromise the password.
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts
at guessing and brute-force attacks.
Password complexity is one factor of several that determines how long it takes to crack a password. The more
complex the password, the greater the number of possible combinations that need to be tested before
the password is compromised. References:
1, 12, 15, 16, 5, 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-000069-GPOS-00037, SRG-OS-000070-GPOS-00038, R31, 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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
- 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 0
tags:
- always
- name: Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters -
Ensure PAM variable ucredit is set accordingly
ansible.builtin.lineinfile:
create: true
dest: /etc/security/pwquality.conf
regexp: ^#?\s*ucredit
line: ucredit = {{ var_password_pam_ucredit }}
when:
- '"kernel" in ansible_facts.packages'
- '"libpwquality" in ansible_facts.packages'
tags:
- 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
- accounts_password_pam_ucredit
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { rpm --quiet -q libpwquality; }; then
var_password_pam_ucredit='0'
# 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' <<< "^ucredit")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_ucredit"
# 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 "^ucredit\\>" "/etc/security/pwquality.conf"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^ucredit\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
else
if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
fi
printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 2 rules |
Set PAM 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. 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, 0418, 1055, 1402 |
Set PAM Password Hashing Algorithm - system-auth
[ref]ruleThe PAM system service can be configured to only store encrypted representations of passwords.
In "/etc/pam.d/system-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. 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, R68, 0418, 1055, 1402, 8.3.2, 8.3 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CJIS-5.6.2.2
- 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 Password Hashing Algorithm - system-auth - Check if /etc/pam.d/system-auth
file is present
ansible.builtin.stat:
path: /etc/pam.d/system-auth
register: result_pam_auth_file_present
when:
- '"kernel" in ansible_facts.packages'
- '"pam" in ansible_facts.packages'
tags:
- CJIS-5.6.2.2
- 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 Password Hashing Algorithm - system-auth - Check the proper remediation
for the system
block:
- name: Set PAM Password Hashing Algorithm - system-auth - Define the PAM file to
be edited as a local fact
ansible.builtin.set_fact:
pam_file_path: /etc/pam.d/system-auth
- name: Set PAM Password Hashing Algorithm - system-auth - Check if system relies
on authselect tool
ansible.builtin.stat:
path: /usr/bin/authselect
register: result_authselect_present
- name: Set PAM Password Hashing Algorithm - system-auth - Ensure authselect custom
profile is used if authselect is present
block:
- name: Set PAM Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - Define a fact for control
already filtered in case filters are used
ansible.builtin.set_fact:
pam_module_control: sufficient
- name: Set PAM Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - Include or update the
PAM module line in {{ pam_file_path }}
block:
- name: Set PAM Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - Define a fact for control
already filtered in case filters are used
ansible.builtin.set_fact:
pam_module_control: sufficient
- name: Set PAM Password Hashing Algorithm - system-auth - 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.split("|")[0] }}\b
state: absent
check_mode: true
changed_when: false
register: result_pam_module_set_password_hashing_algorithm_systemauth_option_present
- name: Set PAM Password Hashing Algorithm - system-auth - Ensure the "{{ var_password_hashing_algorithm_pam.split("|")[0]
}}" 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.split("|")[0] }}
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 Password Hashing Algorithm - system-auth - 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" in ansible_facts.packages'
- '"pam" in ansible_facts.packages'
- result_pam_auth_file_present.stat.exists
tags:
- CJIS-5.6.2.2
- 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 Password Hashing Algorithm - system-auth - Check if /etc/pam.d/system-auth
File is Present
ansible.builtin.stat:
path: /etc/pam.d/system-auth
register: result_pam_auth_file_present
when:
- '"kernel" in ansible_facts.packages'
- '"pam" in ansible_facts.packages'
tags:
- CJIS-5.6.2.2
- 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 Password Hashing Algorithm - system-auth - Check The Proper Remediation
For The System
block:
- name: Set PAM Password Hashing Algorithm - system-auth - Define the PAM file to
be edited as a local fact
ansible.builtin.set_fact:
pam_file_path: /etc/pam.d/system-auth
- name: Set PAM Password Hashing Algorithm - system-auth - Check if system relies
on authselect tool
ansible.builtin.stat:
path: /usr/bin/authselect
register: result_authselect_present
- name: Set PAM Password Hashing Algorithm - system-auth - Ensure authselect custom
profile is used if authselect is present
block:
- name: Set PAM Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - 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 Password Hashing Algorithm - system-auth - Check if "{{ pam_file_path
}}" File is Present
ansible.builtin.stat:
path: '{{ pam_file_path }}'
register: pam_file_path_present
- name: Set PAM Password Hashing Algorithm - system-auth - 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.split('|')[0]
- pam_file_path_present.stat.exists
loop:
- sha512
- yescrypt
- gost_yescrypt
- blowfish
- sha256
- md5
- bigcrypt
register: result_pam_hashing_options_removal
- name: Set PAM Password Hashing Algorithm - system-auth - 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" in ansible_facts.packages'
- '"pam" in ansible_facts.packages'
- result_pam_auth_file_present.stat.exists
tags:
- CJIS-5.6.2.2
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { rpm --quiet -q pam; }; then
var_password_hashing_algorithm_pam='sha512'
# Allow multiple algorithms, but choose the first one for remediation
var_password_hashing_algorithm_pam="$(echo $var_password_hashing_algorithm_pam | cut -d \| -f 1)"
PAM_FILE_PATH="/etc/pam.d/system-auth"
# Ensure all the hashing algorithm option is removed.
declare -a HASHING_ALGORITHMS_OPTIONS=("sha512" "yescrypt" "gost_yescrypt" "blowfish" "sha256" "md5" "bigcrypt")
for hash_option in "${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/$PAM_FILE_NAME"
authselect apply-changes -b
fi
if ! grep -qP "^\s*password\s+sufficient\s+pam_unix.so\s*.*" "$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.*)/\1sufficient \2/" "$PAM_FILE_PATH"
else
echo "password sufficient pam_unix.so" >> "$PAM_FILE_PATH"
fi
fi
# Check the option
if ! grep -qP "^\s*password\s+sufficient\s+pam_unix.so\s*.*\s$var_password_hashing_algorithm_pam\b" "$PAM_FILE_PATH"; then
sed -i -E --follow-symlinks "/\s*password\s+sufficient\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
|
Ensure PAM Displays Last Logon/Access Notification
[ref]ruleTo configure the system to notify users of last logon/access using pam_lastlog,
add or correct the pam_lastlog settings in /etc/pam.d/postlogin
to include showfailed option, such as:
session [default=1] pam_lastlog.so showfailed
And make sure that the silent option is not set for this specific line.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. Warning:
authselect contains an authselect feature to easily and properly enable Last Logon
notifications with pam_lastlog.so module. If a custom profile was created and used
in the system before this authselect feature was available, the new feature can't be used
with this custom profile and the remediation will fail. In this case, the custom profile
should be recreated or manually updated. Rationale:Users need to be aware of activity that occurs regarding their account. Providing users with
information regarding the number of unsuccessful attempts that were made to login to their
account allows the user to determine if any unauthorized activity has occurred and gives them
an opportunity to notify administrators. References:
1, 12, 15, 16, 5.5.2, 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, Req-10.2.4, SRG-OS-000480-GPOS-00227, 10.2.1.4, 10.2.1, 10.2 |
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 1 rule |
Require Authentication for Emergency Systemd Target
[ref]ruleEmergency mode is intended as a system recovery
method, providing a single user root access to the system
during a failed boot sequence.
By default, Emergency mode is protected by requiring a password and is set
in /usr/lib/systemd/system/emergency.service. Rationale:This prevents attackers with physical access from trivially bypassing security
on the machine and gaining root access. Such accesses are further prevented
by configuring the bootloader password. 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, 3.1.1, 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, IA-2, AC-3, CM-6(a), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.PT-3, SRG-OS-000080-GPOS-00048, 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- NIST-800-171-3.1.1
- NIST-800-171-3.4.5
- NIST-800-53-AC-3
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-2
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- require_emergency_target_auth
- restrict_strategy
- name: Require emergency mode password
ansible.builtin.lineinfile:
create: true
dest: /usr/lib/systemd/system/emergency.service
regexp: ^#?ExecStart=
line: ExecStart=-/bin/sh -c "/sbin/sulogin; /usr/bin/systemctl --fail --no-block
default"
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.1
- NIST-800-171-3.4.5
- NIST-800-53-AC-3
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-2
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- require_emergency_target_auth
- restrict_strategy
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
service_file="/usr/lib/systemd/system/emergency.service"
sulogin='/bin/sh -c "/sbin/sulogin; /usr/bin/systemctl --fail --no-block default"'
if grep "^ExecStart=.*" "$service_file" ; then
sed -i "s%^ExecStart=.*%ExecStart=-$sulogin%" "$service_file"
else
echo "ExecStart=-$sulogin" >> "$service_file"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 17 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. 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, 8.2.6, 8.2 |
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 180
The profile requirement is 180.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. 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, 0418, 1055, 1402, 8.3.9, 8.3 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { rpm --quiet -q shadow-utils; }; then
var_accounts_maximum_age_login_defs='180'
# 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
printf '%s\n' "$formatted_output" >> "/etc/login.defs"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Set Password Minimum Age
[ref]ruleTo specify password minimum age for new accounts,
edit the file /etc/login.defs
and add or correct the following line:
PASS_MIN_DAYS 1
A value of 1 day is considered sufficient for many
environments.
The profile requirement is 1.Rationale:Enforcing a minimum password lifetime helps to prevent repeated password
changes to defeat the password reuse or history enforcement requirement. If
users are allowed to immediately and continually change their password,
then the password could be repeatedly changed in a short period of time to
defeat the organization's policy regarding password reuse.
Setting the minimum password age protects against users cycling back to a
favorite password after satisfying the password reuse requirement. References:
1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.8, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(f), IA-5(1)(d), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, SRG-OS-000075-GPOS-00043, 0418, 1055, 1402 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { rpm --quiet -q shadow-utils; }; then
var_accounts_minimum_age_login_defs='1'
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(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 '$a'\\ "/etc/login.defs"
fi
printf '%s\n' "$formatted_output" >> "/etc/login.defs"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Set Existing Passwords Maximum Age
[ref]ruleConfigure non-compliant accounts to enforce a 180-day maximum password lifetime
restriction by running the following command:
$ sudo chage -M 180 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. |
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(d)
- NIST-800-53-IA-5(f)
- 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" in ansible_facts.packages'
tags:
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(d)
- NIST-800-53-IA-5(f)
- 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: |
chage -m {{ var_accounts_minimum_age_login_defs }} {{ item }}
with_items: '{{ user_names.stdout_lines }}'
when:
- '"kernel" in ansible_facts.packages'
- user_names.stdout_lines | length > 0
tags:
- NIST-800-53-CM-6(a)
- NIST-800-53-IA-5(1)(d)
- NIST-800-53-IA-5(f)
- accounts_password_set_min_life_existing
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
var_accounts_minimum_age_login_defs='1'
while IFS= read -r i; do
chage -m $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
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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_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" in ansible_facts.packages'
tags:
- 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_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" 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:
- 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_warn_age_existing
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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 $1}' /etc/shadow)
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Set Password Warning Age
[ref]ruleTo specify how many days prior to password
expiration that a warning will be issued to users,
edit the file /etc/login.defs and add or correct
the following line:
PASS_WARN_AGE 7
The profile requirement is 7.Rationale:Setting the password warning age enables users to
make the change at a practical time. References:
1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.8, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, IA-5(f), IA-5(1)(d), CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, Req-8.2.4, 0418, 1055, 1402, 8.3.9, 8.3 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { rpm --quiet -q shadow-utils; }; then
var_accounts_password_warn_age_login_defs='7'
# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(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 '$a'\\ "/etc/login.defs"
fi
printf '%s\n' "$formatted_output" >> "/etc/login.defs"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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. 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, 8.2.6, 8.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- user_names is not skipped and user_names.stdout_lines | length > 0
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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 3 rules |
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. |
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. |
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. 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 |
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 2 rules |
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 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. 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, 1491, 8.2.2, 8.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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" 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:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
readarray -t systemaccounts < <(awk -F: '($3 < 1000 && $1 != "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
|
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. |
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. |
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 5 rules |
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 1 rule |
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/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. 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, R36 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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/bashrc is already set
ansible.builtin.lineinfile:
path: /etc/bashrc
regexp: ^[^#]*\bumask\s+\d+$
state: absent
check_mode: true
changed_when: false
register: umask_replace
when:
- '"kernel" in ansible_facts.packages'
- '"bash" in ansible_facts.packages'
tags:
- 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/bashrc
ansible.builtin.replace:
path: /etc/bashrc
regexp: ^([^#]*\b)umask\s+\d+$
replace: \g<1>umask {{ var_accounts_user_umask }}
when:
- '"kernel" in ansible_facts.packages'
- '"bash" in ansible_facts.packages'
- umask_replace.found > 0
tags:
- 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/bashrc
line: umask {{ var_accounts_user_umask }}
when:
- '"kernel" in ansible_facts.packages'
- '"bash" in ansible_facts.packages'
- umask_replace.found == 0
tags:
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { rpm --quiet -q bash; }; then
var_accounts_user_umask='027'
grep -q "^[^#]*\bumask" /etc/bashrc && \
sed -i -E -e "s/^([^#]*\bumask)[[:space:]]+[[:digit:]]+/\1 $var_accounts_user_umask/g" /etc/bashrc
if ! [ $? -eq 0 ]; then
echo "umask $var_accounts_user_umask" >> /etc/bashrc
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 a file loaded by /etc/profile, e.g.
/etc/profile.d/tmout.sh should read as follows:
typeset -xr TMOUT=900
or
declare -xr TMOUT=900
Using the typeset keyword is preferred for wider compatibility with ksh and other shells.Rationale: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. 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, R32, 8.6.1, 8.6 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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: Correct any occurrence of TMOUT in /etc/profile
ansible.builtin.replace:
path: /etc/profile
regexp: ^[^#].*TMOUT=.*
replace: typeset -xr TMOUT={{ var_accounts_tmout }}
register: profile_replaced
when: '"kernel" in ansible_facts.packages'
tags:
- 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
ansible.builtin.lineinfile:
path: /etc/profile.d/tmout.sh
create: true
regexp: TMOUT=
line: typeset -xr TMOUT={{ var_accounts_tmout }}
state: present
when: '"kernel" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
var_accounts_tmout='900'
# if 0, no occurrence of tmout found, if 1, occurrence found
tmout_found=0
for f in /etc/profile /etc/profile.d/*.sh; do
if grep --silent '^[^#].*TMOUT' $f; then
sed -i -E "s/^(.*)TMOUT\s*=\s*(\w|\$)*(.*)$/typeset -xr TMOUT=$var_accounts_tmout\3/g" $f
tmout_found=1
fi
done
if [ $tmout_found -eq 0 ]; then
echo -e "\n# Set TMOUT to $var_accounts_tmout per security requirements" >> /etc/profile.d/tmout.sh
echo "typeset -xr TMOUT=$var_accounts_tmout" >> /etc/profile.d/tmout.sh
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- item.value[1]|int >= 1000
- item.value[1]|int != 65534
tags:
- accounts_user_interactive_home_directory_exists
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
All User Files and Directories In The Home Directory Must Have Mode 0750 Or Less Permissive
[ref]ruleSet the mode on files and directories in the local interactive user home
directory with the following command:
$ sudo chmod 0750 /home/USER/FILE_DIR
Files that begin with a "." are excluded from this requirement.Rationale:If a local interactive user files have excessive permissions, unintended users
may be able to access or modify them. Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- accounts_users_home_files_permissions
- 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" in ansible_facts.packages'
tags:
- accounts_users_home_files_permissions
- 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" in ansible_facts.packages'
tags:
- accounts_users_home_files_permissions
- 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:
- '"kernel" in ansible_facts.packages'
- item.value[1]|int >= 1000
- item.value[1]|int != 65534
- item.value[4] != "/"
tags:
- accounts_users_home_files_permissions
- 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: true
loop: '{{ local_users|zip(path_exists.results)|list }}'
when:
- '"kernel" in ansible_facts.packages'
- item.1.stat is defined and item.1.stat.exists
tags:
- accounts_users_home_files_permissions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
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" -perm /7027 \! -type l -exec chmod u-s,g-w-s,o=- {} \;
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 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:
- 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:
- 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:
- 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:
- file_permissions_home_directories
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
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
|
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 TencentOS Server 4 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. 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, R29, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
)
- not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
)
tags:
- 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-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
)
- not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
)
tags:
- 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-common" in ansible_facts.packages and "kernel" 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:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if ( rpm --quiet -q grub2-common && rpm --quiet -q kernel ) && { ( ! ( [ -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
|
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. 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, R29, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
)
- not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
)
tags:
- 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-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
)
- not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
)
tags:
- 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-common" in ansible_facts.packages and "kernel" 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:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if ( rpm --quiet -q grub2-common && rpm --quiet -q kernel ) && { ( ! ( [ -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
|
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. 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, R29, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
)
- not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
)
tags:
- 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-common" in ansible_facts.packages and "kernel" 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:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if ( rpm --quiet -q grub2-common && rpm --quiet -q kernel ) && { ( ! ( [ -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
|
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-setpassword
When prompted, enter the password that was selected.
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. 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, R5 |
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-setpassword
When prompted, enter the password that was selected.
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. 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, R5 |
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 TencentOS Server 4, 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 10 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 TencentOS Server 4 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 3 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. 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, R71, 0988, 1405, 10.3.2, 10.3 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- 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($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
register: rsyslog_new_inc
changed_when: false
when:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_groupownership
- name: Ensure Log Files Are Owned By Appropriate Group - Aggregate rsyslog includes
ansible.builtin.set_fact:
include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
}}'
when:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
- rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
tags:
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_groupownership
- name: Ensure Log Files Are Owned By Appropriate Group - List all config files
ansible.builtin.find:
paths: '{{ item | dirname }}'
patterns: '{{ item | basename }}'
hidden: false
follow: true
loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
when:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
- include_config_output is defined
register: rsyslog_config_files
failed_when: false
changed_when: false
tags:
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_groupownership
- name: Ensure Log Files Are Owned By Appropriate Group - Extract log files old format
ansible.builtin.shell: |
set -o pipefail
grep -oP '^[^(\s|#|\$)]+[\s]*.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
- rsyslog_config_files is not skipped
tags:
- 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 -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
tr -d "\"" | \
grep -v '^/dev/' || true
loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
register: log_files_new
changed_when: false
when:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
- rsyslog_config_files is not skipped
tags:
- 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && 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
# exclude /dev/* paths (e.g., /dev/console)
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 "\"" | grep -v "^/dev/")")
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
|
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. 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, R71, 0988, 1405, 10.3.2, 10.3 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- 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($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
register: rsyslog_new_inc
changed_when: false
when:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_ownership
- name: Ensure Log Files Are Owned By Appropriate User - Aggregate rsyslog includes
ansible.builtin.set_fact:
include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
}}'
when:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
- rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
tags:
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_ownership
- name: Ensure Log Files Are Owned By Appropriate User - List all config files
ansible.builtin.find:
paths: '{{ item | dirname }}'
patterns: '{{ item | basename }}'
hidden: false
follow: true
loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
when:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
- include_config_output is defined
register: rsyslog_config_files
failed_when: false
changed_when: false
tags:
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_ownership
- name: Ensure Log Files Are Owned By Appropriate User - Extract log files old format
ansible.builtin.shell: |
set -o pipefail
grep -oP '^[^(\s|#|\$)]+[\s]*.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
- rsyslog_config_files is not skipped
tags:
- 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 -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
tr -d "\"" | \
grep -v '^/dev/' || true
loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
register: log_files_new
changed_when: false
when:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
- rsyslog_config_files is not skipped
tags:
- 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && 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
# exclude /dev/* paths (e.g., /dev/console)
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 "\"" | grep -v "^/dev/")")
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
|
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. 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, R71, 0988, 1405, 10.3.1, 10.3 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- 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($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
register: rsyslog_new_inc
changed_when: false
when:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_permissions
- name: Ensure System Log Files Have Correct Permissions - Aggregate rsyslog includes
ansible.builtin.set_fact:
include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
}}'
when:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
- rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
tags:
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_permissions
- name: Ensure System Log Files Have Correct Permissions - List all config files
ansible.builtin.find:
paths: '{{ item | dirname }}'
patterns: '{{ item | basename }}'
hidden: false
follow: true
loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
when:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
- include_config_output is defined
register: rsyslog_config_files
failed_when: false
changed_when: false
tags:
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.1
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.1
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- rsyslog_files_permissions
- name: Ensure System Log Files Have Correct Permissions - Extract log files old format
ansible.builtin.shell: |
set -o pipefail
grep -oP '^[^(\s|#|\$)]+[\s]*.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
- rsyslog_config_files is not skipped
tags:
- 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 -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
tr -d "\"" | \
grep -v '^/dev/' || true
loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
register: log_files_new
changed_when: false
when:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
- rsyslog_config_files is not skipped
tags:
- 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- 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:
- '"kernel" in ansible_facts.packages'
- '"rsyslog" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && 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
# exclude /dev/* paths (e.g., /dev/console)
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 "\"" | grep -v "^/dev/")")
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
|
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 5 rules |
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, TencentOS Server 4 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 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 script: (show)
[customizations.services]
enabled = ["systemd-journald"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- 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" 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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- journald_compress
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Setting unquoted shell-style assignment of 'Compress' to 'yes' in '/etc/systemd/journald.conf'
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/systemd/journald.conf
create: true
regexp: (?i)^\s*Compress=
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/systemd/journald.conf
ansible.builtin.lineinfile:
path: /etc/systemd/journald.conf
create: true
regexp: (?i)^\s*Compress=
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/systemd/journald.conf
ansible.builtin.lineinfile:
path: /etc/systemd/journald.conf
create: true
regexp: (?i)^\s*Compress=
line: Compress=yes
state: present
insertbefore: ^# Compress
validate: /usr/bin/bash -n %s
when: '"kernel" in ansible_facts.packages'
tags:
- journald_compress
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
if [ -e "/etc/systemd/journald.conf" ] ; then
LC_ALL=C sed -i "/^\s*Compress\s*=\s*/d" "/etc/systemd/journald.conf"
else
touch "/etc/systemd/journald.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/systemd/journald.conf"
cp "/etc/systemd/journald.conf" "/etc/systemd/journald.conf.bak"
# Insert before the line matching the regex '^#\s*Compress'.
line_number="$(LC_ALL=C grep -n "^#\s*Compress" "/etc/systemd/journald.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
# There was no match of '^#\s*Compress', insert at
# the end of the file.
printf '%s\n' "Compress=yes" >> "/etc/systemd/journald.conf"
else
head -n "$(( line_number - 1 ))" "/etc/systemd/journald.conf.bak" > "/etc/systemd/journald.conf"
printf '%s\n' "Compress=yes" >> "/etc/systemd/journald.conf"
tail -n "+$(( line_number ))" "/etc/systemd/journald.conf.bak" >> "/etc/systemd/journald.conf"
fi
# Clean up after ourselves.
rm "/etc/systemd/journald.conf.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- journald_forward_to_syslog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Setting unquoted shell-style assignment of 'ForwardToSyslog' to 'yes' in '/etc/systemd/journald.conf'
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/systemd/journald.conf
create: true
regexp: (?i)^\s*ForwardToSyslog=
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/systemd/journald.conf
ansible.builtin.lineinfile:
path: /etc/systemd/journald.conf
create: true
regexp: (?i)^\s*ForwardToSyslog=
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/systemd/journald.conf
ansible.builtin.lineinfile:
path: /etc/systemd/journald.conf
create: true
regexp: (?i)^\s*ForwardToSyslog=
line: ForwardToSyslog=yes
state: present
insertbefore: ^# ForwardToSyslog
validate: /usr/bin/bash -n %s
when: '"kernel" in ansible_facts.packages'
tags:
- journald_forward_to_syslog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
if [ -e "/etc/systemd/journald.conf" ] ; then
LC_ALL=C sed -i "/^\s*ForwardToSyslog\s*=\s*/d" "/etc/systemd/journald.conf"
else
touch "/etc/systemd/journald.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/systemd/journald.conf"
cp "/etc/systemd/journald.conf" "/etc/systemd/journald.conf.bak"
# Insert before the line matching the regex '^#\s*ForwardToSyslog'.
line_number="$(LC_ALL=C grep -n "^#\s*ForwardToSyslog" "/etc/systemd/journald.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
# There was no match of '^#\s*ForwardToSyslog', insert at
# the end of the file.
printf '%s\n' "ForwardToSyslog=yes" >> "/etc/systemd/journald.conf"
else
head -n "$(( line_number - 1 ))" "/etc/systemd/journald.conf.bak" > "/etc/systemd/journald.conf"
printf '%s\n' "ForwardToSyslog=yes" >> "/etc/systemd/journald.conf"
tail -n "+$(( line_number ))" "/etc/systemd/journald.conf.bak" >> "/etc/systemd/journald.conf"
fi
# Clean up after ourselves.
rm "/etc/systemd/journald.conf.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- journald_storage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Setting unquoted shell-style assignment of 'Storage' to 'persistent' in '/etc/systemd/journald.conf'
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/systemd/journald.conf
create: true
regexp: (?i)^\s*Storage=
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/systemd/journald.conf
ansible.builtin.lineinfile:
path: /etc/systemd/journald.conf
create: true
regexp: (?i)^\s*Storage=
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/systemd/journald.conf
ansible.builtin.lineinfile:
path: /etc/systemd/journald.conf
create: true
regexp: (?i)^\s*Storage=
line: Storage=persistent
state: present
insertbefore: ^# Storage
validate: /usr/bin/bash -n %s
when: '"kernel" in ansible_facts.packages'
tags:
- journald_storage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
if [ -e "/etc/systemd/journald.conf" ] ; then
LC_ALL=C sed -i "/^\s*Storage\s*=\s*/d" "/etc/systemd/journald.conf"
else
touch "/etc/systemd/journald.conf"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/systemd/journald.conf"
cp "/etc/systemd/journald.conf" "/etc/systemd/journald.conf.bak"
# Insert before the line matching the regex '^#\s*Storage'.
line_number="$(LC_ALL=C grep -n "^#\s*Storage" "/etc/systemd/journald.conf.bak" | LC_ALL=C sed 's/:.*//g')"
if [ -z "$line_number" ]; then
# There was no match of '^#\s*Storage', insert at
# the end of the file.
printf '%s\n' "Storage=persistent" >> "/etc/systemd/journald.conf"
else
head -n "$(( line_number - 1 ))" "/etc/systemd/journald.conf.bak" > "/etc/systemd/journald.conf"
printf '%s\n' "Storage=persistent" >> "/etc/systemd/journald.conf"
tail -n "+$(( line_number ))" "/etc/systemd/journald.conf.bak" >> "/etc/systemd/journald.conf"
fi
# Clean up after ourselves.
rm "/etc/systemd/journald.conf.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- result_systemd_unit_files.stdout_lines is search("systemd-journal-remote.socket")
tags:
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- socket_systemd-journal-remote_disabled
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
Ensure rsyslog is Installed
[ref]ruleRsyslog is installed by default. The rsyslog package can be installed with the following command: $ sudo dnf install rsyslog Rationale:The rsyslog package provides the rsyslog daemon, which provides
system logging services. 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, 1409 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_rsyslog
class install_rsyslog {
package { 'rsyslog':
ensure => 'installed',
}
}
Remediation script: (show)
[[packages]]
name = "rsyslog"
version = "*"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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 TencentOS Server 4.
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. 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, 1409 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 script: (show)
[customizations.services]
enabled = ["rsyslog"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- 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" in ansible_facts.packages'
|
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 33 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 TencentOS Server 4 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 dnf 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.
TencentOS Server 4 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)." Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_firewalld
class install_firewalld {
package { 'firewalld':
ensure => 'installed',
}
}
Remediation script: (show)
[[packages]]
name = "firewalld"
version = "*"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- NIST-800-53-CM-6(a)
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_firewalld_installed
- name: Ensure firewalld is installed
ansible.builtin.package:
name: firewalld
state: present
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-53-CM-6(a)
- 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. 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, AC-4, CM-7(b), CA-3(5), SC-7(21), CM-6(a), 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, SYS.1.6.A5, SYS.1.6.A21, 1409, 1.2.1, 1.2 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include enable_firewalld
class enable_firewalld {
service {'firewalld':
enable => true,
ensure => 'running',
}
}
Remediation script: (show)
[customizations.services]
enabled = ["firewalld"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- NIST-800-171-3.1.3
- NIST-800-171-3.4.7
- NIST-800-53-AC-4
- NIST-800-53-CA-3(5)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(21)
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_firewalld_enabled
- name: Verify firewalld Enabled - Enable service firewalld
block:
- name: Gather the package facts
ansible.builtin.package_facts:
manager: auto
- name: Verify firewalld Enabled - Enable Service firewalld
ansible.builtin.systemd:
name: firewalld
enabled: true
state: started
masked: false
when:
- '"firewalld" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.3
- NIST-800-171-3.4.7
- NIST-800-53-AC-4
- NIST-800-53-CA-3(5)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(21)
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_firewalld_enabled
- special_service_block
when:
- '"kernel" in ansible_facts.packages'
- '"firewalld" in ansible_facts.packages'
|
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. 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, 1416, 1.3.1, 1.3 |
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. 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 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_ra
- name: Configure Accepting Router Advertisements on All IPv6 Interfaces - Find all
files that set net.ipv6.conf.all.accept_ra to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.all.accept_ra\s*=\s*{{ sysctl_net_ipv6_conf_all_accept_ra_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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. 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, R13 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_redirects
- name: Disable Accepting ICMP Redirects for All IPv6 Interfaces - Find all files
that set net.ipv6.conf.all.accept_redirects to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.all.accept_redirects\s*=\s*{{ sysctl_net_ipv6_conf_all_accept_redirects_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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. 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, R13 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces
- Find all files that set net.ipv6.conf.all.accept_source_route to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.all.accept_source_route\s*=\s*{{ sysctl_net_ipv6_conf_all_accept_source_route_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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. 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 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_all_forwarding
- name: Disable Kernel Parameter for IPv6 Forwarding - Find all files that set net.ipv6.conf.all.forwarding
to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.all.forwarding\s*=\s*{{ sysctl_net_ipv6_conf_all_forwarding_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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. 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 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_ra
- name: Disable Accepting Router Advertisements on all IPv6 Interfaces by Default
- Find all files that set net.ipv6.conf.default.accept_ra to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.default.accept_ra\s*=\s*{{ sysctl_net_ipv6_conf_default_accept_ra_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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. 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, R13 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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_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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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_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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_redirects
- name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces
- Find all files that set net.ipv6.conf.default.accept_redirects to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.default.accept_redirects\s*=\s*{{ sysctl_net_ipv6_conf_default_accept_redirects_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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_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" 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:
- 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_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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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_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. 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, R13, 1.4.2, 1.4 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(b)
- NIST-800-53-CM-6.1(iv)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv6_conf_default_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces
by Default - Find all files that set net.ipv6.conf.default.accept_source_route
to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv6.conf.default.accept_source_route\s*=\s*{{ sysctl_net_ipv6_conf_default_accept_source_route_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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 16 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 13 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." 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, R12 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CJIS-5.10.1.1
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_redirects
- name: Disable Accepting ICMP Redirects for All IPv4 Interfaces - Find all files
that set net.ipv4.conf.all.accept_redirects to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.accept_redirects\s*=\s*{{ sysctl_net_ipv4_conf_all_accept_redirects_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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" 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:
- CJIS-5.10.1.1
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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. 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, R12 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces
- Find all files that set net.ipv4.conf.all.accept_source_route to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.accept_source_route\s*=\s*{{ sysctl_net_ipv4_conf_all_accept_source_route_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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
|
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. 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 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_all_log_martians
- unknown_severity
- name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces - Find
all files that set net.ipv4.conf.all.log_martians to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.log_martians\s*=\s*{{ sysctl_net_ipv4_conf_all_log_martians_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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
|
Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
[ref]ruleTo set the runtime status of the net.ipv4.conf.all.rp_filter kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.all.rp_filter=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.rp_filter = 1 Rationale:Enabling reverse path filtering drops packets with source addresses
that should not have been able to be received on the interface they were
received on. It should not be used on systems which are routers for
complicated networks, but is helpful for end hosts and routers serving small
networks. References:
1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, 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), 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.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227, R12, 1.4.3, 1.4 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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_rp_filter
- name: XCCDF Value sysctl_net_ipv4_conf_all_rp_filter_value # promote to variable
set_fact:
sysctl_net_ipv4_conf_all_rp_filter_value: !!str 1
tags:
- always
- name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
- Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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_rp_filter
- name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
- Find all files that contain net.ipv4.conf.all.rp_filter
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.rp_filter\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_rp_filter
- name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
- Find all files that set net.ipv4.conf.all.rp_filter to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.rp_filter\s*=\s*{{ sysctl_net_ipv4_conf_all_rp_filter_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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_rp_filter
- name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
- Comment out any occurrences of net.ipv4.conf.all.rp_filter from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.all.rp_filter
replace: '#net.ipv4.conf.all.rp_filter'
loop: '{{ find_all_values.stdout_lines }}'
when:
- '"kernel" 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:
- 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_rp_filter
- name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
- Ensure sysctl net.ipv4.conf.all.rp_filter is set
ansible.posix.sysctl:
name: net.ipv4.conf.all.rp_filter
value: '{{ sysctl_net_ipv4_conf_all_rp_filter_value }}'
sysctl_file: /etc/sysctl.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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_rp_filter
|
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. 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, R12, 1.4.3, 1.4 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_secure_redirects
- name: Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces
- Find all files that set net.ipv4.conf.all.secure_redirects to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.secure_redirects\s*=\s*{{ sysctl_net_ipv4_conf_all_secure_redirects_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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. 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, R12, 1.4.3, 1.4 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CJIS-5.10.1.1
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_redirects
- name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces
- Find all files that set net.ipv4.conf.default.accept_redirects to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.accept_redirects\s*=\s*{{ sysctl_net_ipv4_conf_default_accept_redirects_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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" 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:
- CJIS-5.10.1.1
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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. 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, R12 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_accept_source_route
- name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces
by Default - Find all files that set net.ipv4.conf.default.accept_source_route
to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.accept_source_route\s*=\s*{{ sysctl_net_ipv4_conf_default_accept_source_route_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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
- 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" 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:
- 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
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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
- 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. 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 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(3)(a)
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_conf_default_log_martians
- unknown_severity
- name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces by Default
- Find all files that set net.ipv4.conf.default.log_martians to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.log_martians\s*=\s*{{ sysctl_net_ipv4_conf_default_log_martians_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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
|
Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces by Default
[ref]ruleTo set the runtime status of the net.ipv4.conf.default.rp_filter kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.default.rp_filter=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.rp_filter = 1 Rationale:Enabling reverse path filtering drops packets with source addresses
that should not have been able to be received on the interface they were
received on. It should not be used on systems which are routers for
complicated networks, but is helpful for end hosts and routers serving small
networks. References:
1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, 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), 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.PT-4, SRG-OS-000480-GPOS-00227, R12 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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_default_rp_filter
- name: XCCDF Value sysctl_net_ipv4_conf_default_rp_filter_value # promote to variable
set_fact:
sysctl_net_ipv4_conf_default_rp_filter_value: !!str 1
tags:
- always
- name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
by Default - Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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_default_rp_filter
- name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
by Default - Find all files that contain net.ipv4.conf.default.rp_filter
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.rp_filter\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_rp_filter
- name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
by Default - Find all files that set net.ipv4.conf.default.rp_filter to correct
value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.rp_filter\s*=\s*{{ sysctl_net_ipv4_conf_default_rp_filter_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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_default_rp_filter
- name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
by Default - Comment out any occurrences of net.ipv4.conf.default.rp_filter from
config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*net.ipv4.conf.default.rp_filter
replace: '#net.ipv4.conf.default.rp_filter'
loop: '{{ find_all_values.stdout_lines }}'
when:
- '"kernel" 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:
- 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_default_rp_filter
- name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
by Default - Ensure sysctl net.ipv4.conf.default.rp_filter is set
ansible.posix.sysctl:
name: net.ipv4.conf.default.rp_filter
value: '{{ sysctl_net_ipv4_conf_default_rp_filter_value }}'
sysctl_file: /etc/sysctl.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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_default_rp_filter
|
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. 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, R12 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_secure_redirects
- name: Configure Kernel Parameter for Accepting Secure Redirects By Default - Find
all files that set net.ipv4.conf.default.secure_redirects to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.secure_redirects\s*=\s*{{ sysctl_net_ipv4_conf_default_secure_redirects_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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. 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, 1.4.2, 1.4 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_icmp_echo_ignore_broadcasts
- name: Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces
- Find all files that set net.ipv4.icmp_echo_ignore_broadcasts to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.icmp_echo_ignore_broadcasts\s*=\s*{{ sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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. 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, R12, 1.4.2, 1.4 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- PCI-DSS-Req-1.4.3
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.2
- disable_strategy
- low_complexity
- medium_disruption
- reboot_required
- sysctl_net_ipv4_icmp_ignore_bogus_error_responses
- unknown_severity
- name: Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces
- Find all files that set net.ipv4.icmp_ignore_bogus_error_responses to correct
value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.icmp_ignore_bogus_error_responses\s*=\s*{{ sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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. 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, R12, 1.4.3, 1.4 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CJIS-5.10.1.1
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5(1)
- NIST-800-53-SC-5(2)
- NIST-800-53-SC-5(3)(a)
- PCI-DSS-Req-1.4.1
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_tcp_syncookies
- name: Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces - Find
all files that set net.ipv4.tcp_syncookies to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.tcp_syncookies\s*=\s*{{ sysctl_net_ipv4_tcp_syncookies_value
}}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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" 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:
- CJIS-5.10.1.1
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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. 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, R12, 1.4.5, 1.4 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CJIS-5.10.1.1
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_all_send_redirects
- name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
- Find all files that set net.ipv4.conf.all.send_redirects to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.all.send_redirects\s*=\s*0$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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" 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:
- CJIS-5.10.1.1
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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. 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, R12, 1.4.5, 1.4 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CJIS-5.10.1.1
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.5
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_conf_default_send_redirects
- name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
by Default - Find all files that set net.ipv4.conf.default.send_redirects to correct
value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.conf.default.send_redirects\s*=\s*0$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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" 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:
- CJIS-5.10.1.1
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.10.1.1
- 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. 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-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), 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, R12, 1.4.3, 1.4 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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-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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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-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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.20
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- NIST-800-53-SC-5
- NIST-800-53-SC-7(a)
- PCI-DSS-Req-1.3.1
- PCI-DSS-Req-1.3.2
- PCI-DSSv4-1.4
- PCI-DSSv4-1.4.3
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_net_ipv4_ip_forward
- name: Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces - Find all files
that set net.ipv4.ip_forward to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*net.ipv4.ip_forward\s*=\s*0$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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-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" 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:
- 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-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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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-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 4 rules |
Install nftables Package
[ref]rulenftables provides a new in-kernel packet classification framework that is based on a
network-specific Virtual Machine (VM) and a new nft userspace command line tool.
nftables reuses the existing Netfilter subsystems such as the existing hook infrastructure,
the connection tracking system, NAT, userspace queuing and logging subsystem.
The nftables package can be installed with the following command:
$ sudo dnf install nftables Rationale:nftables is a subsystem of the Linux kernel that can protect against threats
originating from within a corporate network to include malicious mobile code and poorly
configured software on a host. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_nftables
class install_nftables {
package { 'nftables':
ensure => 'installed',
}
}
Remediation script: (show)
[[packages]]
name = "nftables"
version = "*"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_nftables_installed
- name: Ensure nftables is installed
ansible.builtin.package:
name: nftables
state: present
when: ( "kernel" in ansible_facts.packages )
tags:
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.1
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_nftables_installed
|
Verify nftables Service is Enabled
[ref]ruleThe nftables service allows for the loading of nftables rulesets during boot,
or starting on the nftables service
The nftables service can be enabled with the following command:
$ sudo systemctl enable nftables.service Rationale:The nftables service restores the nftables rules from the rules files referenced
in the /etc/sysconfig/nftables.conf file during boot or the starting of
the nftables service Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include enable_nftables
class enable_nftables {
service {'nftables':
enable => true,
ensure => 'running',
}
}
Remediation script: (show)
[customizations.services]
enabled = ["nftables"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_nftables_enabled
- name: Verify nftables Service is Enabled - Enable service nftables
block:
- name: Gather the package facts
ansible.builtin.package_facts:
manager: auto
- name: Verify nftables Service is Enabled - Enable Service nftables
ansible.builtin.systemd:
name: nftables
enabled: true
state: started
masked: false
when:
- '"nftables" in ansible_facts.packages'
tags:
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_nftables_enabled
- special_service_block
when: ( "nftables" in ansible_facts.packages and "kernel" in ansible_facts.packages
)
|
Ensure nftables Default Deny Firewall Policy
[ref]ruleBase chain policy is the default verdict that will be applied to packets reaching the end of
the chain. There are two policies: accept (Default) and drop. If the policy is set to accept,
the firewall will accept any packet that is not configured to be denied and the packet will
continue traversing the network stack.
Run the following commands and verify that base chains contain a policy of DROP.
$ nft list ruleset | grep 'hook input'
type filter hook input priority 0; policy drop;
$ nft list ruleset | grep 'hook forward'
type filter hook forward priority 0; policy drop;
$ nft list ruleset | grep 'hook output'
type filter hook output priority 0; policy drop;
Warning:
Changing firewall settings while connected over network can result in being locked out
of the system. Rationale:It is easier to allow acceptable usage than to block unacceptable usage.
|
Set nftables Configuration for Loopback Traffic
[ref]ruleConfigure the loopback interface to accept traffic.
Configure all other interfaces to deny traffic to the loopback
network. Warning:
Changing firewall settings while connected over network can
result in being locked out of the system.
Keep in mind the remediation makes changes only to the running
system, in order to keep the changes need to take care to save
the nft settings to the relvant configutation files. Rationale:Loopback traffic is generated between processes on machine and is
typically critical to operation of the system. The loopback interface
is the only place that loopback network traffic should be seen,
all other interfaces should ignore traffic on this network as an
anti-spoofing measure. Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- PCI-DSS-Req-1.4.1
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- set_nftables_loopback_traffic
- name: Implement Loopback Rules
ansible.builtin.command: nft add rule inet filter input iif lo accept
when: ( "nftables" in ansible_facts.packages )
tags:
- PCI-DSS-Req-1.4.1
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- set_nftables_loopback_traffic
- name: Create Rule to Drop Input IP Address from Loopback
ansible.builtin.command: nft add rule inet filter input ip saddr 127.0.0.0/8 counter
drop
when: ( "nftables" in ansible_facts.packages )
tags:
- PCI-DSS-Req-1.4.1
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- set_nftables_loopback_traffic
- name: Check if IPv6 is Disabled in grub Configuration
ansible.builtin.shell: |
[ -z "$(grep "^\s*linux" /boot/grub2/grub.cfg | grep -v ipv6.disabled=1)" ]
register: ipv6_status
changed_when: false
check_mode: false
when: ( "nftables" in ansible_facts.packages )
tags:
- PCI-DSS-Req-1.4.1
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- set_nftables_loopback_traffic
- name: Check sysctl value of net.ipv6.conf.all.disable_ipv6
ansible.posix.sysctl:
name: net.ipv6.conf.all.disable_ipv6
state: present
value: '1'
check_mode: true
register: sysctl_ipv6_all
when: ( "nftables" in ansible_facts.packages )
tags:
- PCI-DSS-Req-1.4.1
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- set_nftables_loopback_traffic
- name: Check sysctl value of net.ipv6.conf.default.disable_ipv6
ansible.posix.sysctl:
name: net.ipv6.conf.default.disable_ipv6
state: present
value: '1'
check_mode: true
register: sysctl_ipv6_default
when: ( "nftables" in ansible_facts.packages )
tags:
- PCI-DSS-Req-1.4.1
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- set_nftables_loopback_traffic
- name: Implement IPv6 loopback rules
ansible.builtin.command: nft add rule inet filter input ip6 saddr ::1 counter drop
when:
- ( "nftables" in ansible_facts.packages )
- ipv6_status is not skipped
- sysctl_ipv6_default is not skipped
- sysctl_ipv6_all is not skipped
- ipv6_status.rc == 0 or sysctl_ipv6_all.found > 0 or sysctl_ipv6_default.found
> 0
tags:
- PCI-DSS-Req-1.4.1
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- set_nftables_loopback_traffic
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ( rpm --quiet -q nftables && ! (systemctl is-active firewalld &>/dev/null) ) ); then
grubfile="/boot/grub2/grub.cfg"
# Implement the loopback rules:
nft add rule inet filter input iif lo accept
nft add rule inet filter input ip saddr 127.0.0.0/8 counter drop
# Check IPv6 is disabled, if false implement IPv6 loopback rules
disabled="false"
[ -f "$grubfile" ] && ! grep "^\s*linux" "$grubfile" | grep -vq "ipv6.disable=1" && disabled="true"
grep -Eq "^\s*net\.ipv6\.conf\.all\.disable_ipv6\s*=\s*1\b(\s+#.*)?$" \
/etc/sysctl.conf /etc/sysctl.d/*.conf && \
grep -Eq "^\s*net\.ipv6\.conf\.default\.disable_ipv6\s*=\s*1\b(\s+#.*)?$" \
/etc/sysctl.conf /etc/sysctl.d/*.conf && sysctl net.ipv6.conf.all.disable_ipv6 | \
grep -Eq "^\s*net\.ipv6\.conf\.all\.disable_ipv6\s*=\s*1\b(\s+#.*)?$" && \
sysctl net.ipv6.conf.default.disable_ipv6 | \
grep -Eq "^\s*net\.ipv6\.conf\.default\.disable_ipv6\s*=\s*1\b(\s+#.*)?$" && disabled="true"
# Is IPv6 Disabled? (true/false)
if [ "$disabled" = false ] ; then
nft add rule inet filter input ip6 saddr ::1 counter drop
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 2 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. 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, 1.4.2, 1.4 |
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. 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, 1.4.2, 1.4 |
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 1 rule |
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 1 rule |
Deactivate Wireless Network Interfaces
[ref]ruleDeactivating wireless network interfaces should prevent normal usage of the wireless
capability.
Configure the system to disable all wireless network interfaces with the following command:
$ sudo nmcli radio all off 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. 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, 1315, 1319, 1.3.3, 1.3 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | false |
|---|
| Strategy: | unknown |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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: Deactivate Wireless Network Interfaces - Service facts
ansible.builtin.service_facts: null
when: ( not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman",
"container"] ) )
tags:
- 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: Deactivate Wireless Network Interfaces - Ensure NetworkManager is installed
ansible.builtin.package:
name: '{{ item }}'
state: present
with_items:
- NetworkManager
when: ( not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman",
"container"] ) )
tags:
- 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: Deactivate Wireless Network Interfaces - 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:
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if ( ( ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) ); then
if ! rpm -q --quiet "NetworkManager" ; then
dnf install -y "NetworkManager"
fi
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
|
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 TencentOS Server 4
installations:
$ mount -t xfs | awk '{print $3}'
For any systems that use a different
local filesystem type, modify this command as appropriate. |
| contains 44 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 29 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 24 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 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:
- 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:
- 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:
- 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
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
|
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 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:
- 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:
- 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:
- 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
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
|
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 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:
- 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:
- 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:
- 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
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
|
Verify User Who Owns Backup shadow File
[ref]rule To properly set the group owner of /etc/shadow-, run the command:
$ sudo chgrp 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 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: '0'
tags:
- 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:
- 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:
- 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
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 "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/shadow-" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/shadow-
fi
fi
|
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. 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, R50, 2.2.6, 2.2 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:
- 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:
- 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:
- 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
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
|
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. 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, R50 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:
- 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:
- 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:
- 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
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
|
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. 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, R50, 2.2.6, 2.2 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:
- 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:
- 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:
- 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
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
|
Verify Group Who Owns shadow File
[ref]rule To properly set the group owner of /etc/shadow, run the command:
$ sudo chgrp root /etc/shadow
Rationale:The /etc/shadow file stores password hashes. Protection of this file is
critical for system security. 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, R50, 2.2.6, 2.2 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: '0'
tags:
- 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:
- 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:
- 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
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 "${newgroup}" ]]; then
>&2 echo "0 is not a defined group on the system"
else
if ! stat -c "%g %G" "/etc/shadow" | grep -E -w -q "0"; then
chgrp --no-dereference "$newgroup" /etc/shadow
fi
fi
|
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 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:
- 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:
- 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:
- 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
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
|
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 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:
- 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:
- 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:
- 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
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
|
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 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:
- 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:
- 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:
- 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
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
|
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 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:
- 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:
- 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:
- 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
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
|
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. 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, R50, 2.2.6, 2.2 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:
- 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:
- 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:
- 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
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
|
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. 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, R50 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:
- 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:
- 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:
- 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
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
|
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. 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, R50, 2.2.6, 2.2 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:
- 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:
- 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:
- 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
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
|
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. 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, R50, 2.2.6, 2.2 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:
- 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:
- 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:
- 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
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
|
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 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:
- 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:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/group-
|
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 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:
- 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:
- NIST-800-53-AC-6 (1)
- configure_strategy
- file_permissions_backup_etc_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xwrs,g-xwrs,o-xwrt /etc/gshadow-
|
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 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:
- 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:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/passwd-
|
Verify Permissions on Backup shadow File
[ref]rule
To properly set the permissions of /etc/shadow-, run the command:
$ sudo chmod 0000 /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 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:
- 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-xwrs,g-xwrs,o-xwrt on /etc/shadow-
ansible.builtin.file:
path: /etc/shadow-
mode: u-xwrs,g-xwrs,o-xwrt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xwrs,g-xwrs,o-xwrt /etc/shadow-
|
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. 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, R50, 2.2.6, 2.2 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:
- 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:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/group
|
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. 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, R50 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:
- 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:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xwrs,g-xwrs,o-xwrt /etc/gshadow
|
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. 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, R50, 2.2.6, 2.2 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:
- 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:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xs,g-xws,o-xwt /etc/passwd
|
Verify Permissions on shadow File
[ref]rule
To properly set the permissions of /etc/shadow, run the command:
$ sudo chmod 0000 /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. 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, R50, 2.2.6, 2.2 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:
- 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-xwrs,g-xwrs,o-xwrt on /etc/shadow
ansible.builtin.file:
path: /etc/shadow
mode: u-xwrs,g-xwrs,o-xwrt
when: file_exists.stat is defined and file_exists.stat.exists
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
chmod u-xwrs,g-xwrs,o-xwrt /etc/shadow
|
Ensure All SGID Executables Are Authorized
[ref]ruleThe SGID (set group id) bit should be set only on files that were installed via authorized
means. A straightforward means of identifying unauthorized SGID files is determine if any were
not installed as part of an RPM package, which is cryptographically verified. Investigate the
origin of any unpackaged SGID files. This configuration check considers authorized SGID 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 SGID 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 SGID permission run with the privileges of the owner of the file.
SGID files of uncertain provenance could allow for unprivileged users to elevate privileges.
The presence of these files should be strictly controlled on the system. 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, R56, 1409 |
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. 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, R56, 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. 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, R54, 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 Group
[ref]ruleIf any file is not group-owned by a valid defined group, the cause of the lack of
group-ownership must be investigated. Following this, those files should be deleted or
assigned to an appropriate group. The groups need to be defined in /etc/group
or in /usr/lib/group if nss-altfiles are configured to be used
in /etc/nsswitch.conf.
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 group using the following command:
$ sudo find MOUNTPOINT -xdev -nogroup 2>/dev/null Warning:
This rule only considers local groups as valid groups.
If you have your groups defined outside /etc/group or /usr/lib/group, the rule won't consider those. 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. References:
1, 11, 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, 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, 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, CM-6(a), AC-6(1), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, PR.PT-3, SRG-OS-000480-GPOS-00227, R53, 2.2.6, 2.2 |
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. 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, R53, 2.2.6, 2.2 |
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 3 rules |
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. 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 |
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. 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 |
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. 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, 3.4.2, 3.4 |
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 5 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. 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, 1409 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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'
ansible.builtin.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:
- 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() | map(''lower'') | list }}'
- '{{ 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:
- 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:
- 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 |
default(''''))~('','' if (mount_info.options | default('''')) else '''')~''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 | default(''))
tags:
- 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'
ansible.posix.mount:
path: /dev/shm
src: '{{ mount_info.source | default('''') }}'
opts: '{{ mount_info.options | default('''') }}'
state: mounted
fstype: '{{ mount_info.fstype | default('''') }}'
register: mount_result
failed_when:
- mount_result is failed
- '''target is busy'' not in (mount_result.msg | default(''''))'
- '''already mounted'' not in (mount_result.msg | default(''''))'
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:
- 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
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
|
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. 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, 1409 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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'
ansible.builtin.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:
- 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() | map(''lower'') | list }}'
- '{{ 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:
- 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:
- 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 |
default(''''))~('','' if (mount_info.options | default('''')) else '''')~''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 | default(''))
tags:
- 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'
ansible.posix.mount:
path: /dev/shm
src: '{{ mount_info.source | default('''') }}'
opts: '{{ mount_info.options | default('''') }}'
state: mounted
fstype: '{{ mount_info.fstype | default('''') }}'
register: mount_result
failed_when:
- mount_result is failed
- '''target is busy'' not in (mount_result.msg | default(''''))'
- '''already mounted'' not in (mount_result.msg | default(''''))'
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:
- 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
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
|
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. 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, 1409 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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'
ansible.builtin.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:
- 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() | map(''lower'') | list }}'
- '{{ 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:
- 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:
- 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 |
default(''''))~('','' if (mount_info.options | default('''')) else '''')~''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 | default(''))
tags:
- 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'
ansible.posix.mount:
path: /dev/shm
src: '{{ mount_info.source | default('''') }}'
opts: '{{ mount_info.options | default('''') }}'
state: mounted
fstype: '{{ mount_info.fstype | default('''') }}'
register: mount_result
failed_when:
- mount_result is failed
- '''target is busy'' not in (mount_result.msg | default(''''))'
- '''already mounted'' not in (mount_result.msg | default(''''))'
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:
- 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
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
|
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. 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 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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'
ansible.builtin.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:
- 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() | map(''lower'') | list }}'
- '{{ 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:
- 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:
- 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 |
default(''''))~('','' if (mount_info.options | default('''')) else '''')~''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 | default(''))
tags:
- 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'
ansible.posix.mount:
path: /tmp
src: '{{ mount_info.source | default('''') }}'
opts: '{{ mount_info.options | default('''') }}'
state: mounted
fstype: '{{ mount_info.fstype | default('''') }}'
register: mount_result
failed_when:
- mount_result is failed
- '''target is busy'' not in (mount_result.msg | default(''''))'
- '''already mounted'' not in (mount_result.msg | default(''''))'
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:
- 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
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
|
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. 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, R28 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | high |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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'
ansible.builtin.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:
- 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() | map(''lower'') | list }}'
- '{{ 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:
- 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:
- 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 |
default(''''))~('','' if (mount_info.options | default('''')) else '''')~''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 | default(''))
tags:
- 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'
ansible.posix.mount:
path: /tmp
src: '{{ mount_info.source | default('''') }}'
opts: '{{ mount_info.options | default('''') }}'
state: mounted
fstype: '{{ mount_info.fstype | default('''') }}'
register: mount_result
failed_when:
- mount_result is failed
- '''target is busy'' not in (mount_result.msg | default(''''))'
- '''already mounted'' not in (mount_result.msg | default(''''))'
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:
- 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
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
|
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 7 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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
- '"systemd" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- '"systemd" in ansible_facts.packages'
tags:
- 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" 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:
- 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" in ansible_facts.packages'
- '"systemd" in ansible_facts.packages'
- count_of_systemd_dropin_files_with_section | int == 0
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { 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 "(?m)^[[:space:]]*\[Coredump\]([^\n\[]*\n+)+?[[:space:]]*ProcessSizeMax" "$f"; then
if ! grep -qzosP "(?m)^[[:space:]]*ProcessSizeMax[[:space:]]*=[[:space:]]*0" "$f"; then
sed -i "/^[[:space:]]*ProcessSizeMax/s/\([[:blank:]]*=[[:blank:]]*\).*/\10/" "$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
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
- '"systemd" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- '"systemd" in ansible_facts.packages'
tags:
- 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" 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:
- 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" in ansible_facts.packages'
- '"systemd" in ansible_facts.packages'
- count_of_systemd_dropin_files_with_section | int == 0
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { 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 "(?m)^[[:space:]]*\[Coredump\]([^\n\[]*\n+)+?[[:space:]]*Storage" "$f"; then
if ! grep -qzosP "(?m)^[[:space:]]*Storage[[:space:]]*=[[:space:]]*none" "$f"; then
sed -i "/^[[:space:]]*Storage/s/\([[:blank:]]*=[[:blank:]]*\).*/\1none/" "$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" >> "$file"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Disable Core Dumps for All Users
[ref]ruleTo disable core dumps for all users, add the following line to
/etc/security/limits.conf, or to a file within the
/etc/security/limits.d/ directory:
* hard core 0 Rationale:A core dump includes a memory image taken at the time the operating system
terminates an application. The memory image could contain sensitive data and is generally useful
only for developers trying to debug problems. References:
1, 12, 13, 15, 16, 2, 7, 8, APO13.01, BAI04.04, DSS01.03, DSS03.05, DSS05.07, SR 6.2, SR 7.1, SR 7.2, A.12.1.3, A.17.2.1, CM-6, SC-7(10), DE.CM-1, PR.DS-4, SRG-OS-000480-GPOS-00227, 3.3.1.1, 3.3.1, 3.3 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- NIST-800-53-CM-6
- NIST-800-53-SC-7(10)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_users_coredumps
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Disable Core Dumps for All Users - Set dirs, files and regex variables
ansible.builtin.set_fact:
limits_dropin_dir: /etc/security/limits.d
limits_dropin_file: /etc/security/limits.d/10-ssg-hardening.conf
limits_main_file: /etc/security/limits.conf
limits_correct_regex: ^\s*\*\s+hard\s+core\s+0\s*$
when:
- '"kernel" in ansible_facts.packages'
- '"pam" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- '"pam" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- '"pam" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- '"pam" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- '"pam" in ansible_facts.packages'
- invalid_dropins | length > 0
tags:
- 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" in ansible_facts.packages'
- '"pam" in ansible_facts.packages'
- not (valid_dropins.matched | default(0) > 0)
tags:
- 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" in ansible_facts.packages'
- '"pam" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- '"pam" in ansible_facts.packages'
- not core_limit_valid
tags:
- 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" in ansible_facts.packages'
- '"pam" in ansible_facts.packages'
- not core_limit_valid
tags:
- 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. 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), R14, 3.3.1.1, 3.3.1, 3.3 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-53-SI-11(a)
- NIST-800-53-SI-11(b)
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_fs_suid_dumpable
- name: Disable Core Dumps for SUID programs - Find all files that set fs.suid_dumpable
to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*fs.suid_dumpable\s*=\s*0$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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 2 rules |
Restrict Exposed Kernel Pointer Addresses Access
[ref]ruleTo set the runtime status of the kernel.kptr_restrict kernel parameter, run the following command: $ sudo sysctl -w kernel.kptr_restrict=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: kernel.kptr_restrict = 1 Rationale:Exposing kernel pointers (through procfs or seq_printf()) exposes kernel
writeable structures which may contain functions pointers. If a write vulnerability
occurs in the kernel, allowing write access to any of this structure, the kernel can
be compromised. This option disallow any program without the CAP_SYSLOG capability
to get the addresses of kernel pointers by replacing them with 0. References:
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), SC-30(5), CM-6(a), FMT_SMF_EXT.1, SRG-OS-000132-GPOS-00067, SRG-OS-000433-GPOS-00192, SRG-OS-000480-GPOS-00227, R9, 1409 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-30
- NIST-800-53-SC-30(2)
- NIST-800-53-SC-30(5)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_kernel_kptr_restrict
- name: XCCDF Value sysctl_kernel_kptr_restrict_value # promote to variable
set_fact:
sysctl_kernel_kptr_restrict_value: !!str 1
tags:
- always
- name: Restrict Exposed Kernel Pointer Addresses Access - Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-30
- NIST-800-53-SC-30(2)
- NIST-800-53-SC-30(5)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_kernel_kptr_restrict
- name: Restrict Exposed Kernel Pointer Addresses Access - Find all files that contain
kernel.kptr_restrict
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*kernel.kptr_restrict\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-30
- NIST-800-53-SC-30(2)
- NIST-800-53-SC-30(5)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_kernel_kptr_restrict
- name: Restrict Exposed Kernel Pointer Addresses Access - Find all files that set
kernel.kptr_restrict to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*kernel.kptr_restrict\s*=\s*{{ sysctl_kernel_kptr_restrict_value }}$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-30
- NIST-800-53-SC-30(2)
- NIST-800-53-SC-30(5)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_kernel_kptr_restrict
- name: Restrict Exposed Kernel Pointer Addresses Access - Comment out any occurrences
of kernel.kptr_restrict from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*kernel.kptr_restrict
replace: '#kernel.kptr_restrict'
loop: '{{ find_all_values.stdout_lines }}'
when:
- '"kernel" 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:
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-30
- NIST-800-53-SC-30(2)
- NIST-800-53-SC-30(5)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_kernel_kptr_restrict
- name: Restrict Exposed Kernel Pointer Addresses Access - Ensure sysctl kernel.kptr_restrict
is set
ansible.posix.sysctl:
name: kernel.kptr_restrict
value: '{{ sysctl_kernel_kptr_restrict_value }}'
sysctl_file: /etc/sysctl.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-30
- NIST-800-53-SC-30(2)
- NIST-800-53-SC-30(5)
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_kernel_kptr_restrict
|
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. 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, R9, 1409, 3.3.1.1, 3.3.1, 3.3 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- 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*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.7
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-30
- NIST-800-53-SC-30(2)
- PCI-DSS-Req-2.2.1
- PCI-DSSv4-3.3
- PCI-DSSv4-3.3.1
- PCI-DSSv4-3.3.1.1
- disable_strategy
- low_complexity
- medium_disruption
- medium_severity
- reboot_required
- sysctl_kernel_randomize_va_space
- name: Enable Randomized Layout of Virtual Address Space - Find all files that set
kernel.randomize_va_space to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*kernel.randomize_va_space\s*=\s*2$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- 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" 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:
- 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.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- 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
|
Restrict Access to Kernel Message Buffer
[ref]ruleTo set the runtime status of the kernel.dmesg_restrict kernel parameter, run the following command: $ sudo sysctl -w kernel.dmesg_restrict=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: kernel.dmesg_restrict = 1 Rationale:Unprivileged access to the kernel syslog can expose sensitive kernel
address information. References:
3.1.5, 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), FMT_SMF_EXT.1, SRG-OS-000132-GPOS-00067, SRG-OS-000138-GPOS-00069, SRG-APP-000243-CTR-000600, R9, 1546 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | medium |
|---|
| Reboot: | true |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- NIST-800-171-3.1.5
- NIST-800-53-SI-11(a)
- NIST-800-53-SI-11(b)
- disable_strategy
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- sysctl_kernel_dmesg_restrict
- name: Restrict Access to Kernel Message Buffer - Set fact for sysctl paths
ansible.builtin.set_fact:
sysctl_paths:
- /etc/sysctl.d/
- /run/sysctl.d/
- /usr/local/lib/sysctl.d/
- /usr/lib/sysctl.d/
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.5
- NIST-800-53-SI-11(a)
- NIST-800-53-SI-11(b)
- disable_strategy
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- sysctl_kernel_dmesg_restrict
- name: Restrict Access to Kernel Message Buffer - Find all files that contain kernel.dmesg_restrict
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*kernel.dmesg_restrict\s*=\s*.*$'
register: find_all_values
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.5
- NIST-800-53-SI-11(a)
- NIST-800-53-SI-11(b)
- disable_strategy
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- sysctl_kernel_dmesg_restrict
- name: Restrict Access to Kernel Message Buffer - Find all files that set kernel.dmesg_restrict
to correct value
ansible.builtin.shell:
cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
-HP '^\s*kernel.dmesg_restrict\s*=\s*1$'
register: find_correct_value
check_mode: false
changed_when: false
failed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.5
- NIST-800-53-SI-11(a)
- NIST-800-53-SI-11(b)
- disable_strategy
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- sysctl_kernel_dmesg_restrict
- name: Restrict Access to Kernel Message Buffer - Comment out any occurrences of
kernel.dmesg_restrict from config files
ansible.builtin.replace:
path: '{{ item | split(":") | first }}'
regexp: ^[\s]*kernel.dmesg_restrict
replace: '#kernel.dmesg_restrict'
loop: '{{ find_all_values.stdout_lines }}'
when:
- '"kernel" 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:
- NIST-800-171-3.1.5
- NIST-800-53-SI-11(a)
- NIST-800-53-SI-11(b)
- disable_strategy
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- sysctl_kernel_dmesg_restrict
- name: Restrict Access to Kernel Message Buffer - Ensure sysctl kernel.dmesg_restrict
is set to 1
ansible.posix.sysctl:
name: kernel.dmesg_restrict
value: '1'
sysctl_file: /etc/sysctl.conf
state: present
reload: true
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.5
- NIST-800-53-SI-11(a)
- NIST-800-53-SI-11(b)
- disable_strategy
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- sysctl_kernel_dmesg_restrict
|
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 TencentOS Server 4, 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 TencentOS Server 4 system, unless that
system has unusual requirements which make a stronger policy
appropriate. |
| contains 5 rules |
Ensure SELinux Not Disabled in /etc/default/grub
[ref]ruleSELinux can be disabled at boot time by an argument in
/etc/default/grub.
Remove any instances of selinux=0 from the kernel arguments in that
file to prevent SELinux from being disabled at boot. Rationale:Disabling a major host protection feature, such as SELinux, at boot time prevents
it from confining system services at boot time. Further, it increases
the chances that it will remain off during system operation. References:
1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9, APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01, 3.1.2, 3.7.2, 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), 4.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 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, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 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 2.10, 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.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.12.7.1, 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.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, 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-3(3)(a), DE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4, 1.2.6, 1.2 |
Ensure No Daemons are Unconfined by SELinux
[ref]ruleDaemons for which the SELinux policy does not contain rules will inherit the
context of the parent process. Because daemons are launched during
startup and descend from the init process, they inherit the unconfined_service_t context.
To check for unconfined daemons, run the following command:
$ sudo ps -eZ | grep "unconfined_service_t"
It should produce no output in a well-configured system.Warning:
Automatic remediation of this control is not available. Remediation
can be achieved by amending SELinux policy or stopping the unconfined
daemons as outlined above. Rationale:Daemons which run with the unconfined_service_t context may cause AVC denials,
or allow privileges that the daemon does not require. References:
1, 11, 12, 13, 14, 15, 16, 18, 3, 5, 6, 9, APO01.06, APO11.04, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, MEA02.01, 3.1.2, 3.1.5, 3.7.2, 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), 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 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 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-3(3)(a), AC-6, PR.AC-4, PR.DS-5, PR.IP-1, PR.PT-1, PR.PT-3, 1.2.6, 1.2 |
Ensure SELinux is Not Disabled
[ref]ruleThe SELinux state should be set to enforcing or permissive at system boot
time. In the file /etc/selinux/config, add or correct the following line to configure
the system to boot into enforcing or permissive mode:
SELINUX=enforcing
OR
SELINUX=permissive
Ensure that all files have correct SELinux labels by running:
fixfiles onboot
Then reboot the system.Warning:
In case the SELinux is "disabled", the automated remediation will adopt a more
conservative approach and set it to "permissive" in order to avoid any system disruption
and give the administrator the opportunity to assess the impact and necessary efforts
before setting it to "enforcing", which is strongly recommended. Rationale:Running SELinux in disabled mode is strongly discouraged. It prevents enforcing the SELinux
controls without a system reboot. It also avoids labeling any persistent objects such as
files, making it difficult to enable SELinux in the future. Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- high_severity
- low_complexity
- low_disruption
- reboot_required
- restrict_strategy
- selinux_not_disabled
- name: Ensure SELinux is Not Disabled - Check current SELinux state
ansible.builtin.command:
cmd: getenforce
register: current_selinux_state
check_mode: false
changed_when: false
when: '"kernel" in ansible_facts.packages'
tags:
- high_severity
- low_complexity
- low_disruption
- reboot_required
- restrict_strategy
- selinux_not_disabled
- name: Ensure SELinux is Not Disabled
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/selinux/config
create: true
regexp: (?i)^SELINUX=
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/selinux/config
ansible.builtin.lineinfile:
path: /etc/selinux/config
create: true
regexp: (?i)^SELINUX=
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/selinux/config
ansible.builtin.lineinfile:
path: /etc/selinux/config
create: true
regexp: (?i)^SELINUX=
line: SELINUX=permissive
state: present
when: '"kernel" in ansible_facts.packages'
tags:
- high_severity
- low_complexity
- low_disruption
- reboot_required
- restrict_strategy
- selinux_not_disabled
- name: Ensure SELinux is Not Disabled - Mark system to relabel SELinux on next boot
ansible.builtin.file:
path: /.autorelabel
state: touch
access_time: preserve
modification_time: preserve
when:
- '"kernel" in ansible_facts.packages'
- current_selinux_state.stdout | lower != "permissive"
tags:
- high_severity
- low_complexity
- low_disruption
- reboot_required
- restrict_strategy
- selinux_not_disabled
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
if [ -e "/etc/selinux/config" ] ; then
LC_ALL=C sed -i "/^SELINUX=/Id" "/etc/selinux/config"
else
touch "/etc/selinux/config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/selinux/config"
cp "/etc/selinux/config" "/etc/selinux/config.bak"
# Insert at the end of the file
printf '%s\n' "SELINUX=permissive" >> "/etc/selinux/config"
# Clean up after ourselves.
rm "/etc/selinux/config.bak"
fixfiles onboot
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Configure SELinux Policy
[ref]ruleThe SELinux targeted policy is appropriate for
general-purpose desktops and servers, as well as systems in many other roles.
To configure the system to use this policy, add or correct the following line
in /etc/selinux/config:
SELINUXTYPE=targeted
Other policies, such as mls, provide additional security labeling
and greater confinement but are not compatible with many general-purpose
use cases.Rationale:Setting the SELinux policy to targeted or a more specialized policy
ensures the system will confine processes that are likely to be
targeted for exploitation, such as network or system services.
Note: During the development or debugging of SELinux modules, it is common to
temporarily place non-production systems in permissive mode. In such
temporary cases, SELinux policies should be developed, and once work
is completed, the system should be reconfigured to
targeted. References:
1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9, APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01, 3.1.2, 3.7.2, 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), 4.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 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, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 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 2.10, 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.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.12.7.1, 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.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, CIP-003-8 R5.1.1, CIP-003-8 R5.2, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-004-6 R3.3, 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, CIP-007-3 R6.5, AC-3, AC-3(3)(a), AU-9, SC-7(21), DE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4, FMT_MOF_EXT.1, SRG-OS-000445-GPOS-00199, SRG-APP-000233-CTR-000585, R46, R64, APP.4.4.A4, SYS.1.6.A3, SYS.1.6.A18, SYS.1.6.A21, 1409, 1.2.6, 1.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- NIST-800-171-3.1.2
- NIST-800-171-3.7.2
- NIST-800-53-AC-3
- NIST-800-53-AC-3(3)(a)
- NIST-800-53-AU-9
- NIST-800-53-SC-7(21)
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.6
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- selinux_policytype
- name: XCCDF Value var_selinux_policy_name # promote to variable
set_fact:
var_selinux_policy_name: !!str targeted
tags:
- always
- name: Configure SELinux Policy
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/selinux/config
create: true
regexp: (?i)^SELINUXTYPE=
state: absent
check_mode: true
changed_when: false
register: dupes
- name: Deduplicate values from /etc/selinux/config
ansible.builtin.lineinfile:
path: /etc/selinux/config
create: true
regexp: (?i)^SELINUXTYPE=
state: absent
when: dupes.found is defined and dupes.found > 1
- name: Insert correct line to /etc/selinux/config
ansible.builtin.lineinfile:
path: /etc/selinux/config
create: true
regexp: (?i)^SELINUXTYPE=
line: SELINUXTYPE={{ var_selinux_policy_name }}
state: present
when: '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.2
- NIST-800-171-3.7.2
- NIST-800-53-AC-3
- NIST-800-53-AC-3(3)(a)
- NIST-800-53-AU-9
- NIST-800-53-SC-7(21)
- PCI-DSSv4-1.2
- PCI-DSSv4-1.2.6
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- selinux_policytype
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
var_selinux_policy_name='targeted'
if [ -e "/etc/selinux/config" ] ; then
LC_ALL=C sed -i "/^SELINUXTYPE=/Id" "/etc/selinux/config"
else
touch "/etc/selinux/config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/selinux/config"
cp "/etc/selinux/config" "/etc/selinux/config.bak"
# Insert at the end of the file
printf '%s\n' "SELINUXTYPE=$var_selinux_policy_name" >> "/etc/selinux/config"
# Clean up after ourselves.
rm "/etc/selinux/config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Ensure SELinux State is Enforcing
[ref]ruleThe SELinux state should be set to enforcing at
system boot time. In the file /etc/selinux/config, add or correct the
following line to configure the system to boot into enforcing mode:
SELINUX=enforcing
Ensure that all files have correct SELinux labels by running:
fixfiles onboot
Then reboot the system.Rationale:Setting the SELinux state to enforcing ensures SELinux is able to confine
potentially compromised processes to the security policy, which is designed to
prevent them from causing damage to the system or further elevating their
privileges. References:
1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9, APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01, 3.1.2, 3.7.2, 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), 4.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 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, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 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 2.10, 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.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.12.7.1, 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.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, CIP-003-8 R5.1.1, CIP-003-8 R5.2, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-004-6 R3.3, 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, CIP-007-3 R6.5, AC-3, AC-3(3)(a), AU-9, SC-7(21), DE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4, FMT_MOF_EXT.1, SRG-OS-000445-GPOS-00199, SRG-OS-000134-GPOS-00068, R37, R79, APP.4.4.A4, SYS.1.6.A3, SYS.1.6.A18, SYS.1.6.A21, 1409, 1.2.6, 1.2 |
Services
[ref]groupThe best protection against vulnerable software is running less software. This section describes how to review
the software which TencentOS Server 4 installs on a system and disable software which is not needed. It
then enumerates the software packages installed on a default TencentOS Server 4 system and provides guidance about which
ones can be safely disabled.
TencentOS Server 4 provides a convenient minimal install option that essentially installs the bare necessities for a functional
system. When building TencentOS Server 4 systems, it is highly recommended to select the minimal packages and then build up
the system from there. |
| contains 87 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 1 rule |
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 1 rule |
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. 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 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_avahi
class remove_avahi {
package { 'avahi':
ensure => 'purged',
}
}
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:
- 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
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!
if rpm -q --quiet "avahi" ; then
dnf remove -y --noautoremove "avahi"
fi
|
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 8 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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
if [[ -f /etc/at.deny ]]; then
rm /etc/at.deny
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
if [[ -f /etc/cron.deny ]]; then
rm /etc/cron.deny
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- file_exists.stat is defined and file_exists.stat.exists
tags:
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_groupowner_at_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- file_exists.stat is defined and file_exists.stat.exists
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- file_exists.stat is defined and file_exists.stat.exists
tags:
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_owner_at_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- file_exists.stat is defined and file_exists.stat.exists
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- file_exists.stat is defined and file_exists.stat.exists
tags:
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_at_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
chmod u-xs,g-xws,o-xwrt /etc/at.allow
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- file_exists.stat is defined and file_exists.stat.exists
tags:
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- configure_strategy
- file_permissions_cron_allow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
chmod u-xs,g-xws,o-xwrt /etc/cron.allow
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 crond service can be enabled with the following command:
$ sudo systemctl enable crond.service Rationale:Due to its usage for maintenance and security-supporting tasks,
enabling the cron daemon is essential. 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 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include enable_crond
class enable_crond {
service {'crond':
enable => true,
ensure => 'running',
}
}
Remediation script: (show)
[customizations.services]
enabled = ["crond"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- NIST-800-53-CM-6(a)
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_crond_enabled
- name: Enable cron Service - Enable service crond
block:
- name: Gather the package facts
ansible.builtin.package_facts:
manager: auto
- name: Enable cron Service - Enable Service crond
ansible.builtin.systemd:
name: crond
enabled: true
state: started
masked: false
when:
- '"cronie" in ansible_facts.packages'
tags:
- NIST-800-53-CM-6(a)
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_crond_enabled
- special_service_block
when: '"kernel" 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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- file_exists.stat is defined and file_exists.stat.exists
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
Verify Owner on cron.daily
[ref]rule
To properly set the owner of /etc/cron.daily, run the command:
$ sudo chown 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 user to prevent unauthorized changes. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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_daily
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Set the file_owner_cron_daily_newown variable if represented by uid
ansible.builtin.set_fact:
file_owner_cron_daily_newown: '0'
when: '"kernel" in ansible_facts.packages'
tags:
- 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_daily
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure owner on directory /etc/cron.daily/
ansible.builtin.file:
path: /etc/cron.daily/
follow: false
state: directory
owner: '{{ file_owner_cron_daily_newown }}'
when: '"kernel" in ansible_facts.packages'
tags:
- 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_daily
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
newown=""
if id "0" >/dev/null 2>&1; then
newown="0"
fi
if [[ -z "$newown" ]]; then
>&2 echo "0 is not a defined user on the system"
else
find -P /etc/cron.daily/ -maxdepth 0 -type d ! -user 0 -exec chown --no-dereference "$newown" {} \;
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- file_exists.stat is defined and file_exists.stat.exists
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
Verify Permissions on crontab
[ref]rule
To properly set the permissions of /etc/crontab, run the command:
$ sudo chmod 0600 /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 have the
correct access rights to prevent unauthorized changes. 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, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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_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" in ansible_facts.packages'
tags:
- 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_crontab
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- name: Ensure permission u-xs,g-xwrs,o-xwrt on /etc/crontab
ansible.builtin.file:
path: /etc/crontab
mode: u-xs,g-xwrs,o-xwrt
when:
- '"kernel" in ansible_facts.packages'
- file_exists.stat is defined and file_exists.stat.exists
tags:
- 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_crontab
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
chmod u-xs,g-xwrs,o-xwrt /etc/crontab
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 2 rules |
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 package can be removed with the following command:
$ sudo dnf remove dhcp Rationale:Removing the DHCP server ensures that it cannot be easily or
accidentally reactivated and disrupt network operation. 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, R62, 2.2.4, 2.2 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_dhcp
class remove_dhcp {
package { 'dhcp':
ensure => 'purged',
}
}
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall DHCP Server Package: Ensure dhcp is removed'
ansible.builtin.package:
name: dhcp
state: absent
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove dhcp
# from the system, and may remove any packages
# that depend on dhcp. Execute this
# remediation AFTER testing on a non-production
# system!
if rpm -q --quiet "dhcp" ; then
dnf remove -y --noautoremove "dhcp"
fi
|
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. 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 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 script: (show)
[customizations.services]
masked = ["dhcpd"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- 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" 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 2 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 TencentOS Server 4 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 dnf remove bind Rationale:If there is no need to make DNS server software available,
removing it provides a safeguard against its activation. 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 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_bind
class remove_bind {
package { 'bind':
ensure => 'purged',
}
}
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:
- 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
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!
if rpm -q --quiet "bind" ; then
dnf remove -y --noautoremove "bind"
fi
|
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. 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 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 script: (show)
[customizations.services]
masked = ["named"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- 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" 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 2 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 dnf remove vsftpd Rationale:Removing the vsftpd package decreases the risk of its
accidental activation. 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 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_vsftpd
class remove_vsftpd {
package { 'vsftpd':
ensure => 'purged',
}
}
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:
- 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
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!
if rpm -q --quiet "vsftpd" ; then
dnf remove -y --noautoremove "vsftpd"
fi
|
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. 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 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 script: (show)
[customizations.services]
masked = ["vsftpd"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- 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" in ansible_facts.packages'
|
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 dnf remove httpd Rationale:If there is no need to make the web server software available,
removing it provides a safeguard against its activation. 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 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_httpd
class remove_httpd {
package { 'httpd':
ensure => 'purged',
}
}
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:
- 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
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!
if rpm -q --quiet "httpd" ; then
dnf remove -y --noautoremove "httpd"
fi
|
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. 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 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 script: (show)
[customizations.services]
masked = ["httpd"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- 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" 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 2 rules |
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 dnf 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 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:
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- package_dovecot_removed
- unknown_severity
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!
if rpm -q --quiet "dovecot" ; then
dnf remove -y --noautoremove "dovecot"
fi
|
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 Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_dovecot
class disable_dovecot {
service {'dovecot':
enable => false,
ensure => 'stopped',
}
}
Remediation script: (show)
[customizations.services]
masked = ["dovecot"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- service_dovecot_disabled
- special_service_block
- unknown_severity
when: '"kernel" in ansible_facts.packages'
|
LDAP is a popular directory service, that is, a
standardized way of looking up information from a central database.
TencentOS Server 4 includes software that enables a system to act as both
an LDAP client and server. |
| contains 1 rule |
Configure OpenLDAP Server
[ref]groupThis section details some security-relevant settings
for an OpenLDAP server. |
| contains 1 rule |
Uninstall openldap-servers Package
[ref]ruleThe openldap-servers package is not installed by default on a TencentOS Server 4
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. 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 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_openldap-servers
class remove_openldap-servers {
package { 'openldap-servers':
ensure => 'purged',
}
}
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall openldap-servers Package: Ensure openldap-servers is removed'
ansible.builtin.package:
name: openldap-servers
state: absent
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove openldap-servers
# from the system, and may remove any packages
# that depend on openldap-servers. Execute this
# remediation AFTER testing on a non-production
# system!
if rpm -q --quiet "openldap-servers" ; then
dnf remove -y --noautoremove "openldap-servers"
fi
|
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 2 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 1 rule |
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 1 rule |
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 Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_rpcbind
class disable_rpcbind {
service {'rpcbind':
enable => false,
ensure => 'stopped',
}
}
Remediation script: (show)
[customizations.services]
masked = ["rpcbind"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- 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" 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. 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 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 script: (show)
[customizations.services]
masked = ["nfs-server"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- 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" in ansible_facts.packages'
|
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 4 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 dnf 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 Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_chrony
class install_chrony {
package { 'chrony':
ensure => 'installed',
}
}
Remediation script: (show)
[[packages]]
name = "chrony"
version = "*"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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 Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include enable_chronyd
class enable_chronyd {
service {'chronyd':
enable => true,
ensure => 'running',
}
}
Remediation script: (show)
[customizations.services]
enabled = ["chronyd"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- enable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_chronyd_enabled
- special_service_block
when:
- '"kernel" in ansible_facts.packages'
- '"chrony" 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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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.pool.ntp.org,1.pool.ntp.org,2.pool.ntp.org,3.pool.ntp.org
tags:
- always
- name: XCCDF Value var_multiple_time_pools # promote to variable
set_fact:
var_multiple_time_pools: !!str 0.pool.ntp.org,1.pool.ntp.org,2.pool.ntp.org,3.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" in ansible_facts.packages'
- '"chrony" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- '"chrony" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { rpm --quiet -q chrony; }; then
var_multiple_time_servers='0.pool.ntp.org,1.pool.ntp.org,2.pool.ntp.org,3.pool.ntp.org'
var_multiple_time_pools='0.pool.ntp.org,1.pool.ntp.org,2.pool.ntp.org,3.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
|
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 && { 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
|
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 TencentOS Server 4
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 TencentOS Server 4. |
| contains 2 rules |
Uninstall xinetd Package
[ref]ruleThe xinetd package can be removed with the following command:
$ sudo dnf remove xinetd Rationale:Removing the xinetd package decreases the risk of the
xinetd service's accidental (or intentional) activation. 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, R62, 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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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!
if rpm -q --quiet "xinetd" ; then
dnf remove -y --noautoremove "xinetd"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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. 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, 1409 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 script: (show)
[customizations.services]
masked = ["xinetd"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- 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" 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 2 rules |
Uninstall ypserv Package
[ref]ruleThe ypserv package can be removed with the following command:
$ sudo dnf remove ypserv Rationale:The NIS service provides an unencrypted authentication service which does
not provide for the confidentiality and integrity of user passwords or the
remote session.
Removing the ypserv package decreases the risk of the accidental
(or intentional) activation of NIS or NIS+ services. 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), IA-5(1)(c), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, Req-2.2.2, SRG-OS-000095-GPOS-00049, R62, 2.2.4, 2.2 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_ypserv
class remove_ypserv {
package { 'ypserv':
ensure => 'purged',
}
}
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall ypserv Package: Ensure ypserv is removed'
ansible.builtin.package:
name: ypserv
state: absent
tags:
- 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)
- 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_ypserv_removed
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove ypserv
# from the system, and may remove any packages
# that depend on ypserv. Execute this
# remediation AFTER testing on a non-production
# system!
if rpm -q --quiet "ypserv" ; then
dnf remove -y --noautoremove "ypserv"
fi
|
Disable ypserv Service
[ref]ruleThe ypserv service, which allows the system to act as a client in
a NIS or NIS+ domain, should be disabled.
The ypserv service can be disabled with the following command:
$ sudo systemctl mask --now ypserv.service Rationale:Disabling the ypserv service ensures the system is not acting
as a client in a NIS or NIS+ domain. This service should be disabled
unless in use. Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_ypserv
class disable_ypserv {
service {'ypserv':
enable => false,
ensure => 'stopped',
}
}
Remediation script: (show)
[customizations.services]
masked = ["ypserv"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_ypserv_disabled
- name: Disable ypserv Service - Disable service ypserv
block:
- name: Disable ypserv 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 ypserv Service - Ensure ypserv.service is Masked
ansible.builtin.systemd:
name: ypserv.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("ypserv.service", multiline=True)
- name: Unit Socket Exists - ypserv.socket
ansible.builtin.command: systemctl -q list-unit-files ypserv.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable ypserv Service - Disable Socket ypserv
ansible.builtin.systemd:
name: ypserv.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("ypserv.socket", multiline=True)
tags:
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- service_ypserv_disabled
- special_service_block
when: '"kernel" in ansible_facts.packages'
|
Rlogin, Rsh, and Rexec
[ref]groupThe Berkeley r-commands are legacy services which
allow cleartext remote access and have an insecure trust
model. |
| contains 2 rules |
Uninstall rsh Package
[ref]rule
The rsh package contains the client commands
for the rsh services Rationale:These legacy clients contain numerous security exposures and have
been replaced with the more secure SSH package. Even if the server is removed,
it is best to ensure the clients are also removed to prevent users from
inadvertently attempting to use these commands and therefore exposing
their credentials. Note that removing the rsh package removes
the clients for rsh,rcp, and rlogin. 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, R62, 2.2.4, 2.2 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_rsh
class remove_rsh {
package { 'rsh':
ensure => 'purged',
}
}
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: 'Uninstall rsh Package: Ensure rsh is removed'
ansible.builtin.package:
name: rsh
state: absent
tags:
- NIST-800-171-3.1.13
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- package_rsh_removed
- unknown_severity
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
# CAUTION: This remediation script will remove rsh
# from the system, and may remove any packages
# that depend on rsh. Execute this
# remediation AFTER testing on a non-production
# system!
if rpm -q --quiet "rsh" ; then
dnf remove -y --noautoremove "rsh"
fi
|
Disable rsh Service
[ref]ruleThe rsh service, which is available with
the rsh-server package and runs as a service through xinetd or separately
as a systemd socket, should be disabled.
If using xinetd, set disable to yes in /etc/xinetd.d/rsh.
The rsh socket can be disabled with the following command:
$ sudo systemctl mask --now rsh.socket Rationale:The rsh service uses unencrypted network communications, 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. 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 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_rsh
class disable_rsh {
service {'rsh':
enable => false,
ensure => 'stopped',
}
}
Remediation script: (show)
[customizations.services]
masked = ["rsh"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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_rsh_disabled
- name: Disable rsh Service - Disable service rsh
block:
- name: Disable rsh 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 rsh Service - Ensure rsh.service is Masked
ansible.builtin.systemd:
name: rsh.service
state: stopped
enabled: false
masked: true
when: service_exists.stdout_lines is search("rsh.service", multiline=True)
- name: Unit Socket Exists - rsh.socket
ansible.builtin.command: systemctl -q list-unit-files rsh.socket
register: socket_file_exists
changed_when: false
failed_when: socket_file_exists.rc not in [0, 1]
check_mode: false
- name: Disable rsh Service - Disable Socket rsh
ansible.builtin.systemd:
name: rsh.socket
enabled: false
state: stopped
masked: true
when: socket_file_exists.stdout_lines is search("rsh.socket", multiline=True)
tags:
- 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_rsh_disabled
- special_service_block
when: '"kernel" in ansible_facts.packages'
|
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 2 rules |
Uninstall telnet-server Package
[ref]ruleThe telnet-server package can be removed with the following command:
$ sudo dnf 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. 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, R62, 1409, 2.2.4, 2.2 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 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:
- 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
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!
if rpm -q --quiet "telnet-server" ; then
dnf remove -y --noautoremove "telnet-server"
fi
|
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 TencentOS Server 4. 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, R62, 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 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:
- 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
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!
if rpm -q --quiet "telnet" ; then
dnf remove -y --noautoremove "telnet"
fi
|
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 dnf 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. 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, 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 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:
- 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
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!
if rpm -q --quiet "tftp-server" ; then
dnf remove -y --noautoremove "tftp-server"
fi
|
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 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:
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- package_tftp_removed
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!
if rpm -q --quiet "tftp" ; then
dnf remove -y --noautoremove "tftp"
fi
|
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. 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 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 script: (show)
[customizations.services]
masked = ["tftp"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- 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" 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 dnf 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 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:
- disable_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- package_rsync_removed
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!
if rpm -q --quiet "rsync" ; then
dnf remove -y --noautoremove "rsync"
fi
|
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 Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_rsyncd
class disable_rsyncd {
service {'rsyncd':
enable => false,
ensure => 'stopped',
}
}
Remediation script: (show)
[customizations.services]
masked = ["rsyncd"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- 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" 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 dnf 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. 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 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
include remove_cups
class remove_cups {
package { 'cups':
ensure => 'purged',
}
}
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:
- 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
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!
if rpm -q --quiet "cups" ; then
dnf remove -y --noautoremove "cups"
fi
|
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. 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 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 script: (show)
[customizations.services]
masked = ["cups"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- 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" 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 1 rule |
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 1 rule |
Uninstall squid Package
[ref]ruleThe squid package can be removed with the following command: $ sudo dnf 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 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:
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- package_squid_removed
- unknown_severity
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!
if rpm -q --quiet "squid" ; then
dnf remove -y --noautoremove "squid"
fi
|
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 dnf 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 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:
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- package_samba_removed
- unknown_severity
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!
if rpm -q --quiet "samba" ; then
dnf remove -y --noautoremove "samba"
fi
|
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 Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include disable_smb
class disable_smb {
service {'smb':
enable => false,
ensure => 'stopped',
}
}
Remediation script: (show)
[customizations.services]
masked = ["smb"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | disable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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:
- disable_strategy
- low_complexity
- low_disruption
- low_severity
- no_reboot_needed
- service_smb_disabled
- special_service_block
when: '"kernel" 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 1 rule |
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 1 rule |
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 dnf 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 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:
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.4
- disable_strategy
- low_complexity
- low_disruption
- no_reboot_needed
- package_net-snmp_removed
- unknown_severity
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!
if rpm -q --quiet "net-snmp" ; then
dnf remove -y --noautoremove "net-snmp"
fi
|
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 23 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 20 rules |
Set SSH Client Alive Interval
[ref]ruleSSH allows administrators to set a network responsiveness timeout interval.
After this interval has passed, the unresponsive client will be automatically logged out.
To set this timeout interval, edit the following line in /etc/ssh/sshd_config as
follows:
ClientAliveInterval 900
The timeout interval is given in seconds. For example, have a timeout
of 10 minutes, set interval to 600.
If a shorter timeout has already been set for the login shell, that value will
preempt any SSH setting made in /etc/ssh/sshd_config. Keep in mind that
some processes may stop SSH from correctly detecting that the user is idle.Warning:
SSH disconnecting unresponsive clients will not have desired effect without also
configuring ClientAliveCountMax in the SSH service configuration. Warning:
Following conditions may prevent the SSH session to time out:
- Remote processes on the remote machine generates output. As the output has to be transferred over the network to the client, the timeout is reset every time such transfer happens.
- Any
scp or sftp activity by the same user to the host resets the timeout.
Rationale:Terminating an idle ssh 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 let unattended. References:
1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, 5.5.6, APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.11, 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, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.3, 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.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, 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 R2.2.3, 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, CM-6(a), AC-17(a), AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2, Req-8.1.8, SRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109, SRG-OS-000395-GPOS-00175, 8.2.8, 8.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CJIS-5.5.6
- NIST-800-171-3.1.11
- NIST-800-53-AC-12
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-2(5)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-10
- PCI-DSS-Req-8.1.8
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.8
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_set_idle_timeout
- name: XCCDF Value sshd_idle_timeout_value # promote to variable
set_fact:
sshd_idle_timeout_value: !!str 900
tags:
- always
- name: Set SSH Client Alive Interval
block:
- name: Check for duplicate values
ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
create: true
regexp: (?i)(?i)^\s*ClientAliveInterval\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*ClientAliveInterval\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*ClientAliveInterval\s+
line: ClientAliveInterval {{ sshd_idle_timeout_value }}
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.5.6
- NIST-800-171-3.1.11
- NIST-800-53-AC-12
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-2(5)
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-6(a)
- NIST-800-53-SC-10
- PCI-DSS-Req-8.1.8
- PCI-DSSv4-8.2
- PCI-DSSv4-8.2.8
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_set_idle_timeout
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
sshd_idle_timeout_value='900'
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*ClientAliveInterval\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' "ClientAliveInterval $sshd_idle_timeout_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
|
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. 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, 0421, 0422, 0484, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, 8.3.1, 8.3 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 1483 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
- '"openssh-server" in ansible_facts.packages and (((((ansible_facts.packages["openssh-server"]
| last)["epoch"]) != None) | ternary((ansible_facts.packages["openssh-server"]
| last)["epoch"] ~ ":", "0:")) + ((ansible_facts.packages["openssh-server"] |
last)["version"] | split("-") | first)) is version("0:7.0", "<")'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel && { ( rpm --quiet -q openssh-server && { real="$(epoch=$(rpm -q --queryformat '%{EPOCH}' openssh-server); version=$(rpm -q --queryformat '%{VERSION}' openssh-server); [ "$epoch" = "(none)" ] && echo "0:$version" || echo "$epoch:$version")"; expected="0:7.0"; [[ "$real" != "$expected" ]] && printf "%s\n%s" "$real" "$expected" | sort -VC; } ); }; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*Protocol\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$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
|
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. 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, AC-17(a), CM-7(a), CM-7(b), CM-6(a), 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, 1546, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CJIS-5.5.6
- NIST-800-171-3.1.1
- NIST-800-171-3.1.5
- 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-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" in ansible_facts.packages'
tags:
- CJIS-5.5.6
- NIST-800-171-3.1.1
- NIST-800-171-3.1.5
- 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-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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, 1546, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, R33, 1546, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CJIS-5.5.6
- 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" in ansible_facts.packages'
tags:
- CJIS-5.5.6
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_tcp_forwarding
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- NIST-800-53-CM-6(b)
- 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" in ansible_facts.packages'
tags:
- NIST-800-53-CM-6(b)
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_disable_x11_forwarding
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.IP-1, Req-2.2.4, SRG-OS-000480-GPOS-00229, 1546, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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-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" in ansible_facts.packages'
tags:
- 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-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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_enable_pam
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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.net
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. References:
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, SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CJIS-5.5.6
- 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)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_enable_warning_banner_net
- 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.net
state: present
insertbefore: BOF
validate: /usr/sbin/sshd -t -f %s
when: '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.5.6
- 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)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_enable_warning_banner_net
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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.net" > "/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
|
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. 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, 2.2.6, 2.2 |
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. References:
0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_set_max_sessions
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- PCI-DSSv4-2.2
- PCI-DSSv4-2.2.6
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_set_maxstartups
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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 $var_sshd_set_maxstartups" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Use Only Strong Ciphers
[ref]ruleLimit the ciphers to strong algorithms.
Counter (CTR) mode is also preferred over cipher-block chaining (CBC) mode.
The following line in /etc/ssh/sshd_config
demonstrates use of those ciphers:
Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
The man page sshd_config(5) contains a list of supported ciphers.Rationale:Based on research conducted at various institutions, it was determined that the symmetric
portion of the SSH Transport Protocol (as described in RFC 4253) has security weaknesses
that allowed recovery of up to 32 bits of plaintext from a block of ciphertext that was
encrypted with the Cipher Block Chaining (CBD) method. From that research, new Counter
mode algorithms (as described in RFC4344) were designed that are not vulnerable to these
types of attacks and these algorithms are now recommended for standard use. Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
if [ -e "/etc/ssh/sshd_config" ] ; then
LC_ALL=C sed -i "/^\s*Ciphers\s\+/Id" "/etc/ssh/sshd_config"
else
touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$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 ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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 ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-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" in ansible_facts.packages'
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
sshd_strong_kex='ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-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
|
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,hmac-sha2-512-etm@openssh.com,hmac-sha2-256,hmac-sha2-256-etm@openssh.com 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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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,hmac-sha2-512-etm@openssh.com,hmac-sha2-256,hmac-sha2-256-etm@openssh.com
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" in ansible_facts.packages'
tags:
- NIST-800-53-AC-17 (2)
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- sshd_use_strong_macs
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
sshd_strong_macs='hmac-sha2-512,hmac-sha2-512-etm@openssh.com,hmac-sha2-256,hmac-sha2-256-etm@openssh.com'
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
|
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. 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, R50 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- file_exists.stat is defined and file_exists.stat.exists
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, R50 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- file_exists.stat is defined and file_exists.stat.exists
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; 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
|
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. 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, R50, 2.2.6, 2.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- file_exists.stat is defined and file_exists.stat.exists
tags:
- 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
Remediation Shell script: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel; then
chmod u-xs,g-xwrs,o-xwrt /etc/ssh/sshd_config
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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 70 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 56 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. 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-10.5.5, 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, R73, 0582, 10.3.4, 10.3 |
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. 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-10.5.5, 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, R73, 0582, 10.3.4, 10.3 |
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. 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-10.5.5, 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, R73, 10.3.4, 10.3 |
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. 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-10.5.5, 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, R73, 10.3.4, 10.3 |
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. 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-10.5.5, 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, R73, 10.3.4, 10.3 |
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. 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-10.5.5, 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, R73, 10.3.4, 10.3 |
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. 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-10.5.5, 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, R73, 10.3.4, 10.3 |
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. 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-10.5.5, 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, R73, 10.3.4, 10.3 |
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. 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-10.5.5, 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, R73, 10.3.4, 10.3 |
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. 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-10.5.5, 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, R73, 10.3.4, 10.3 |
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. 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-10.5.5, 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, R73, 10.3.4, 10.3 |
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. 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-10.5.5, 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, R73, 10.3.4, 10.3 |
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. 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-10.5.5, 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, R73, 10.3.4, 10.3 |
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 17 rules |
Record Successful Permission Changes to Files - 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 lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S chmod -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S chmod -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
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 chmod -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S chmod -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change 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:File permission changes could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Ownership Changes to Files - chown
[ref]ruleAt a minimum, the audit system should collect file ownership 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 lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S chown -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S chown -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
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 chown -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S chown -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change 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:File ownership attempts could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Permission Changes to Files - 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 lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchmod -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S fchmod -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
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 fchmod -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S fchmod -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change 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:File permission changes could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Permission Changes to Files - 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 lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchmodat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S fchmodat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
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 fchmodat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S fchmodat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change 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:File permission changes could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Ownership Changes to Files - fchown
[ref]ruleAt a minimum, the audit system should collect file ownership 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 lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchown -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S fchown -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
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 fchown -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S fchown -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change 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:File ownership attempts could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Ownership Changes to Files - fchownat
[ref]ruleAt a minimum, the audit system should collect file ownership 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 lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchownat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S fchownat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
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 fchownat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S fchownat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change 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:File ownership attempts could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Permission Changes to Files - 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 lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fremovexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S fremovexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
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 fremovexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S fremovexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change 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:File permission changes could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Permission Changes to Files - 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 lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fsetxattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S fsetxattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
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 fsetxattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S fsetxattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change 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:File permission changes could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Permission Changes to Files - 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 lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S lremovexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S lremovexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
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 lremovexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S lremovexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change 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:File permission changes could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Permission Changes to Files - 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 lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S lsetxattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S lsetxattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
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 lsetxattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S lsetxattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change 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:File permission changes could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Permission Changes to Files - 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 lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S removexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S removexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
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 removexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S removexattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change 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:File permission changes could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Delete Attempts to Files - rename
[ref]ruleAt a minimum, the audit system should collect file
deletion 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 rename -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S rename -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
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 rename -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S rename -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete 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:File deletion attempts could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Delete Attempts to Files - renameat
[ref]ruleAt a minimum, the audit system should collect file
deletion 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 renameat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S renameat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
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 renameat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S renameat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete 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:File deletion attempts could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Permission Changes to Files - 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 lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S setxattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S setxattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
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 setxattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S setxattr -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-perm-change 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:File deletion attempts could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Delete Attempts to Files - unlink
[ref]ruleAt a minimum, the audit system should collect file
deletion 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 unlink -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S unlink -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
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 unlink -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S unlink -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete 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:File deletion attempts could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Record Successful Delete Attempts to Files - unlinkat
[ref]ruleAt a minimum, the audit system should collect file
deletion 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 unlinkat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S unlinkat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
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 unlinkat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete
If the system is 64 bit then also add the following lines:
-a always,exit -F arch=b64 -S unlinkat -F success=1 -F auid>=1000 -F auid!=unset -F key=successful-delete 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:File deletion attempts could be an indicator of malicious activity on a system. Auditing
these events could serve as evidence of potential system compromise. |
Ensure auditd Collects Unauthorized Access Attempts to Files (unsuccessful)
[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,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 the system is 64 bit then also add the following lines:
-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
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,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 the system is 64 bit then also add the following lines:
-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 Warning:
This rule checks for multiple syscalls related to unsuccessful file modification;
it was written with DISA STIG in mind. Other policies should use a
separate rule for each syscall that needs to be checked. For example:
audit_rules_unsuccessful_file_modification_openaudit_rules_unsuccessful_file_modification_ftruncateaudit_rules_unsuccessful_file_modification_creat
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. 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), 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 |
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. 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, 0582 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; 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
|
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. 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-10.2.7, 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, R73 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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_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" 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:
- 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_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" in ansible_facts.packages'
tags:
- 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_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" in ansible_facts.packages'
- audit_arch == "b64"
tags:
- 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_delete
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; 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
|
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. 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-10.2.7, 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, R73 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | configure |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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_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" 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:
- 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_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" in ansible_facts.packages'
tags:
- 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_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" in ansible_facts.packages'
- audit_arch == "b64"
tags:
- 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_init
- configure_strategy
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; 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
|
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 (N/A) -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 (N/A) -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 Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- audit_rules_login_events_faillog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - faillog - Search /etc/audit/rules.d
for other rules with specified key logins
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)logins$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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" 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:
- 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" 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:
- 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" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- audit_rules_login_events_faillog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - faillog - Add watch rule
for /var/log/faillog in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /var/log/faillog -p wa -k logins
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- audit_rules_login_events_faillog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$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
|
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. 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, R73, 0582, 10.2.1.3, 10.2.1, 10.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_lastlog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - lastlog - Search /etc/audit/rules.d
for other rules with specified key logins
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)logins$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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" 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:
- 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" 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:
- 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" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; 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
|
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. 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, 0582, 10.2.1.3, 10.2.1, 10.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.7
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.3
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.3
- audit_rules_login_events_tallylog
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Attempts to Alter Logon and Logout Events - tallylog - Search /etc/audit/rules.d
for other rules with specified key logins
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)logins$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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" 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:
- 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" 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:
- 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" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; 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
|
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 4 rules |
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. 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, R73 |
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. 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, R73 |
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. |
Ensure auditd Collects Information on the Use of Privileged Commands - sudo
[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/sudo -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/sudo -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. 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-OS-000466-GPOS-00210, SRG-APP-000029-CTR-000085, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-OS-000755-GPOS-00220, R33 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; then
# Retrieve hardware architecture of the underlying system
OTHER_FILTERS="-F path=/usr/bin/sudo"
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
|
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. 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, R73, 0582, 10.6.3, 10.6 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" 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:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- audit_arch == "b64"
tags:
- 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 clock_settime
[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 clock_settime -F a0=0x0 -F key=time-change
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S clock_settime -F a0=0x0 -F key=time-change
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 clock_settime -F a0=0x0 -F key=time-change
If the system is 64 bit then also add the following line:
-a always,exit -F arch=b64 -S clock_settime -F a0=0x0 -F key=time-change
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. 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, R73, 0582, 10.6.3, 10.6 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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_clock_settime
- 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" 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:
- 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_clock_settime
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Perform remediation of Audit rules for clock_settime for 32bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- clock_settime
syscall_grouping: []
- name: Check existence of clock_settime 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 a0=0x0 (-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/time-change.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/time-change.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 a0=0x0 (?:-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 a0=0x0 -F
key=time-change
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- clock_settime
syscall_grouping: []
- name: Check existence of clock_settime 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 a0=0x0 (-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 a0=0x0 (?:-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 a0=0x0 -F
key=time-change
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- 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_clock_settime
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Perform remediation of Audit rules for clock_settime for 64bit platform
block:
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- clock_settime
syscall_grouping: []
- name: Check existence of clock_settime 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 a0=0x0 (-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/time-change.rules
ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/time-change.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 a0=0x0 (?:-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 a0=0x0 -F
key=time-change
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
- name: Declare list of syscalls
ansible.builtin.set_fact:
syscalls:
- clock_settime
syscall_grouping: []
- name: Check existence of clock_settime 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 a0=0x0 (-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 a0=0x0 (?:-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 a0=0x0 -F
key=time-change
create: true
mode: g-rwx,o-rwx
state: present
when: syscalls_found | length == 0
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- audit_arch == "b64"
tags:
- 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_clock_settime
- 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. 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, 0582, 10.6.3, 10.6 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" 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:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- audit_arch == "b64"
tags:
- 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. 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, R73, 0582, 10.6.3, 10.6 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
- ( not ( ansible_architecture == "aarch64" ) and not ( ansible_architecture ==
"s390x" ) )
tags:
- 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
|
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. 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, R73, 10.3.2, 10.3 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | true |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- item.stat.exists
tags:
- 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$', multiline=True)
| list
| length == 2
}}
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.3.1
- NIST-800-171-3.4.3
- NIST-800-53-AC-6(9)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.2
- PCI-DSSv4-10.3
- PCI-DSSv4-10.3.2
- audit_rules_immutable
- low_complexity
- low_disruption
- medium_severity
- reboot_required
- restrict_strategy
- name: Make the auditd Configuration Immutable - Remove any existing -e option from
all Audit config files
ansible.builtin.lineinfile:
path: '{{ item }}'
regexp: ^\s*-e\s+.*$
state: absent
loop: '{{ find_rules_d.files | map(attribute=''path'') | list + [''/etc/audit/audit.rules'']
}}'
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- not immutable_correctly_set
tags:
- 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" in ansible_facts.packages'
- not immutable_correctly_set
tags:
- 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" in ansible_facts.packages'
- not immutable_correctly_set
tags:
- 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. 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, R73, 10.3.4, 10.3 |
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. 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 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- NIST-800-171-3.1.8
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.5.5
- audit_rules_mac_modification_usr_share
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify the System's Mandatory Access Controls in usr/share
- Search /etc/audit/rules.d for other rules with specified key MAC-policy
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)MAC-policy$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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" 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:
- 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" 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:
- 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" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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" in ansible_facts.packages'
tags:
- 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" in ansible_facts.packages'
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; 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
|
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. 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, R73, 0582, 10.3.4, 10.3 |
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. 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 |
Ensure auditd Collects System Administrator Actions - /etc/sudoers
[ref]ruleAt a minimum, the audit system should collect administrator actions
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 /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 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.
Editing the sudoers file may be sign of an attacker trying to
establish persistent methods to a system, auditing the editing of the sudoers
files mitigates this risk. References:
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 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- audit_rules_sudoers
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - /etc/sudoers - 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|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- audit_rules_sudoers
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - /etc/sudoers - Search
/etc/audit/rules.d for other rules with specified key actions
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)actions$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- audit_rules_sudoers
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - /etc/sudoers - 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" 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:
- audit_rules_sudoers
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - /etc/sudoers - 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" 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:
- audit_rules_sudoers
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - /etc/sudoers - 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" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- audit_rules_sudoers
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - /etc/sudoers - 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|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- audit_rules_sudoers
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - /etc/sudoers - Add watch
rule for /etc/sudoers in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/sudoers -p wa -k actions
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- audit_rules_sudoers
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; then
# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
# Create a list of audit *.rules files that should be inspected for presence and correctness
# of a particular audit rule. The scheme is as follows:
#
# -----------------------------------------------------------------------------------------
# Tool used to load audit rules | Rule already defined | Audit rules file to inspect |
# -----------------------------------------------------------------------------------------
# auditctl | Doesn't matter | /etc/audit/audit.rules |
# -----------------------------------------------------------------------------------------
# augenrules | Yes | /etc/audit/rules.d/*.rules |
# augenrules | No | /etc/audit/rules.d/$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
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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. 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, AC-2(7)(b), 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-10.2.2, 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, R73, 0582, 10.2.1.5, 10.2.1, 10.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- 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
- 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|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Add watch rule for /etc/sudoers
in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/sudoers -p wa -k actions
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Check if watch rule
for /etc/sudoers already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/sudoers\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- 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
- 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" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- 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
- 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" 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:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- 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
- 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" 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:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- 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
- 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" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- 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
- 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|$)+
patterns: audit.rules
register: find_existing_watch_audit_rules
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Add watch rule for /etc/sudoers.d/
in /etc/audit/audit.rules
ansible.builtin.lineinfile:
line: -w /etc/sudoers.d/ -p wa -k actions
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.2
- PCI-DSS-Req-10.2.5.b
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_sysadmin_actions
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Ensure auditd Collects System Administrator Actions - Check if watch rule
for /etc/sudoers.d/ already exists in /etc/audit/rules.d/
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^\s*-w\s+/etc/sudoers.d/\s+-p\s+wa(\s|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- 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
- 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" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- 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
- 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" 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:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- 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
- 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" 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:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- 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
- 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" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(7)(b)
- 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
- 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. 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, R73, 0582, 10.2.1.5, 10.2.1, 10.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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-10.2.5
- 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|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_group
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/group - Search /etc/audit/rules.d
for other rules with specified key audit_rules_usergroup_modification
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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-10.2.5
- 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" 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:
- 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-10.2.5
- 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" 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:
- 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-10.2.5
- 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" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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-10.2.5
- 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" in ansible_facts.packages'
tags:
- 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-10.2.5
- 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" in ansible_facts.packages'
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- 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-10.2.5
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; 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
|
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. 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, R73, 0582, 10.2.1.5, 10.2.1, 10.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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-10.2.5
- 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|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_gshadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/gshadow - Search /etc/audit/rules.d
for other rules with specified key audit_rules_usergroup_modification
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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-10.2.5
- 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" 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:
- 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-10.2.5
- 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" 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:
- 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-10.2.5
- 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" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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-10.2.5
- 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" in ansible_facts.packages'
tags:
- 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-10.2.5
- 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" in ansible_facts.packages'
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- 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-10.2.5
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; 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
|
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. 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-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000503-CTR-001275, R73, 0582, 10.2.1.5, 10.2.1, 10.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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-10.2.5
- 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|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_opasswd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/security/opasswd -
Search /etc/audit/rules.d for other rules with specified key audit_rules_usergroup_modification
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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-10.2.5
- 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" 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:
- 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-10.2.5
- 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" 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:
- 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-10.2.5
- 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" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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-10.2.5
- 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" in ansible_facts.packages'
tags:
- 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-10.2.5
- 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" in ansible_facts.packages'
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- 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-10.2.5
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; 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
|
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. 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, R73, 0582, 10.2.1.5, 10.2.1, 10.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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-10.2.5
- 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|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_passwd
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/passwd - Search /etc/audit/rules.d
for other rules with specified key audit_rules_usergroup_modification
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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-10.2.5
- 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.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" 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:
- 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-10.2.5
- 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" 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:
- 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-10.2.5
- 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
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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-10.2.5
- 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" in ansible_facts.packages'
tags:
- 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-10.2.5
- 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
state: present
dest: /etc/audit/audit.rules
create: true
mode: '0600'
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- 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-10.2.5
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; 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 $audit_rules_file file
# with proper key
echo "-w /etc/passwd -p wa -k audit_rules_usergroup_modification" >> "$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/$key.rules |
# -----------------------------------------------------------------------------------------
files_to_inspect=()
# If the audit is 'augenrules', then check if rule is already defined
# If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
# If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.
readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/passwd" /etc/audit/rules.d/*.rules)
# For each of the matched entries
for match in "${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 [ "${#files_to_inspect[@]}" -eq "0" ]
then
# Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
# If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
if [ ! -e "$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/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 $audit_rules_file file
# with proper key
echo "-w /etc/passwd -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"
fi
done
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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. 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, R73, 0582, 10.2.1.5, 10.2.1, 10.2 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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-10.2.5
- 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|$)+
patterns: '*.rules'
register: find_existing_watch_rules_d
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- CJIS-5.4.1.1
- NIST-800-171-3.1.7
- NIST-800-53-AC-2(4)
- NIST-800-53-AC-6(9)
- NIST-800-53-AU-12(c)
- NIST-800-53-AU-2(d)
- NIST-800-53-CM-6(a)
- PCI-DSS-Req-10.2.5
- PCI-DSSv4-10.2
- PCI-DSSv4-10.2.1
- PCI-DSSv4-10.2.1.5
- audit_rules_usergroup_modification_shadow
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: Record Events that Modify User/Group Information - /etc/shadow - Search /etc/audit/rules.d
for other rules with specified key audit_rules_usergroup_modification
ansible.builtin.find:
paths: /etc/audit/rules.d
contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
patterns: '*.rules'
register: find_watch_key
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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-10.2.5
- 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" 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:
- 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-10.2.5
- 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" 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:
- 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-10.2.5
- 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" in ansible_facts.packages'
- find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
== 0
tags:
- 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-10.2.5
- 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" in ansible_facts.packages'
tags:
- 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-10.2.5
- 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" in ansible_facts.packages'
- find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
== 0
tags:
- 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-10.2.5
- 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
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; 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
|
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 9 rules |
Configure audispd's Plugin disk_full_action When Disk Is Full
[ref]ruleConfigure the action the operating system takes if the disk the audit records
are written to becomes full. Edit the file /etc/audit/audisp-remote.conf.
Add or modify the following line, substituting ACTION appropriately:
disk_full_action = ACTION
Set this value to single to cause the system to switch to single user
mode for corrective action. Acceptable values also include syslog and
halt. For certain systems, the need for availability
outweighs the need to log all actions, and a different setting should be
determined.Rationale:Taking appropriate action in case of a filled audit storage volume will
minimize the possibility of losing audit records. |
Configure auditd Disk Error Action on Disk Error
[ref]ruleThe auditd service can be configured to take an action
when there is a disk error.
Edit the file /etc/audit/auditd.conf. Add or modify the following line,
substituting ACTION appropriately:
disk_error_action = ACTION
Set this value to single to cause the system to switch to single-user
mode for corrective action. Acceptable values also include
syslog, exec, single, 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:Taking appropriate action in case of disk errors will minimize the possibility of
losing audit records. References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 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, 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, SRG-OS-000047-GPOS-00023, SRG-APP-000098-CTR-000185, SRG-APP-000099-CTR-000190, SRG-APP-000100-CTR-000195, SRG-APP-000100-CTR-000200, SRG-APP-000109-CTR-000215, SRG-APP-000290-CTR-000670, SRG-APP-000357-CTR-000800 |
Configure auditd Disk Full Action when Disk Space Is Full
[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:
disk_full_action = ACTION
Set this value to single to cause the system to switch to single-user
mode for corrective action. Acceptable values also include
syslog, exec, single, 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:Taking appropriate action in case of a filled audit storage volume will minimize
the possibility of losing audit records. References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 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, 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, SRG-OS-000047-GPOS-00023 |
Configure auditd admin_space_left 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 PERCENTAGE appropriately:
admin_space_left = PERCENTAGE%
Set this value to 50
to cause the system to perform an action.Rationale:Notifying administrators of an impending disk space problem may allow them to
take corrective action prior to any disruption. References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 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, 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 Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | restrict |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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_admin_space_left_percentage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
- name: XCCDF Value var_auditd_admin_space_left_percentage # promote to variable
set_fact:
var_auditd_admin_space_left_percentage: !!str 50
tags:
- always
- name: Configure auditd admin_space_left on Low Disk Space
ansible.builtin.lineinfile:
dest: /etc/audit/auditd.conf
line: admin_space_left = {{ var_auditd_admin_space_left_percentage }}%
regexp: ^\s*admin_space_left\s*=\s*.*$
state: present
create: true
when:
- '"audit" in ansible_facts.packages'
- '"kernel" in ansible_facts.packages'
tags:
- 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_admin_space_left_percentage
- low_complexity
- low_disruption
- medium_severity
- no_reboot_needed
- restrict_strategy
Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; then
var_auditd_admin_space_left_percentage='50'
grep -q "^admin_space_left[[:space:]]*=.*$" /etc/audit/auditd.conf && \
sed -i "s/^admin_space_left[[:space:]]*=.*$/admin_space_left = $var_auditd_admin_space_left_percentage%/g" /etc/audit/auditd.conf || \
echo "admin_space_left = $var_auditd_admin_space_left_percentage%" >> /etc/audit/auditd.conf
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
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. 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 |
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. 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 |
Configure auditd Number of Logs Retained
[ref]ruleDetermine how many log files
auditd should retain when it rotates logs.
Edit the file /etc/audit/auditd.conf. Add or modify the following
line, substituting NUMLOGS with the correct value of 5:
num_logs = NUMLOGS
Set the value to 5 for general-purpose systems.
Note that values less than 2 result in no log rotation.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. 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, 3.3.1, 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 Remediation Shell script: (show)
# Remediation is applicable only in certain platforms
if rpm --quiet -q audit && rpm --quiet -q kernel; then
var_auditd_num_logs='5'
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' <<< "^num_logs")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "$var_auditd_num_logs"
# 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 "^num_logs\\>" "$AUDITCONFIG"; then
escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
LC_ALL=C sed -i --follow-symlinks "s/^num_logs\\>.*/$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
printf '%s\n' "$formatted_output" >> "$AUDITCONFIG"
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
|
Configure auditd space_left 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 SIZE_in_MB appropriately:
space_left = SIZE_in_MB
Set this value to the appropriate size in Megabytes cause the system to
notify the user of an issue.Rationale:Notifying administrators of an impending disk space problem may allow them to
take corrective action prior to any disruption. References:
1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 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, 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, 10.5.1, 10.5 |
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. 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, 10.5.1, 10.5 |
Ensure the audit-libs package as a part of audit Subsystem is Installed
[ref]ruleThe audit-libs 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. 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 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_audit-libs
class install_audit-libs {
package { 'audit-libs':
ensure => 'installed',
}
}
Remediation script: (show)
[[packages]]
name = "audit-libs"
version = "*"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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 audit-libs is installed
ansible.builtin.package:
name: audit-libs
state: present
when: '"kernel" in ansible_facts.packages'
tags:
- 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. 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, R33, R73, 0582, 0846, 10.2.1, 10.2 Remediation Puppet snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
include install_audit
class install_audit {
package { 'audit':
ensure => 'installed',
}
}
Remediation script: (show)
[[packages]]
name = "audit"
version = "*"
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- 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" in ansible_facts.packages'
tags:
- 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. 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, R33, R73, 1409, 10.2.1, 10.2 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 script: (show)
[customizations.services]
enabled = ["auditd"]
Remediation Ansible snippet: (show)
| Complexity: | low |
|---|
| Disruption: | low |
|---|
| Reboot: | false |
|---|
| Strategy: | enable |
|---|
- name: Gather the package facts
package_facts:
manager: auto
tags:
- CJIS-5.4.1.1
- 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:
- CJIS-5.4.1.1
- 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" 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 "$(grub2-editenv - list | grep kernelopts) audit=1" Rationale:Each process on the system carries an "auditable" flag which indicates whether
its activities can be audited. Although auditd takes care of enabling
this for all processes which launch after it does, adding the kernel argument
ensures it is set for every process during boot. References:
1, 11, 12, 13, 14, 15, 16, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.02, DSS05.03, DSS05.04, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, 3.3.1, 164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(C), 164.310(a)(2)(iv), 164.310(d)(2)(iii), 164.312(b), 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 7.1, SR 7.6, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2, AC-17(1), AU-14(1), AU-10, CM-6(a), IR-5(1), DE.AE-3, DE.AE-5, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, FAU_GEN.1, Req-10.3, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000473-GPOS-00218, SRG-OS-000254-GPOS-00095, 10.7.2, 10.7 |
Extend Audit Backlog Limit for the Audit Daemon
[ref]ruleTo improve the kernel capacity to queue all log events, even those which occurred
prior to the audit daemon, add the argument audit_backlog_limit=8192 to the default
GRUB 2 command line for the Linux operating system.
Configure the default Grub2 kernel command line to contain audit_backlog_limit=8192 as follows:
# grub2-editenv - set "$(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. 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, 10.7.2, 10.7 |