cyberstrikeus 6.3.4.5 Ensure audit configuration files mode is configured (Automated)
Profile Applicability
- Level 2 - Server
- Level 2 - Workstation
Description
Audit configuration files control auditd and what events are audited.
Rationale
Access to the audit configuration files could allow unauthorized personnel to prevent the auditing of critical events.
Misconfigured audit configuration files may prevent the auditing of critical events or impact the system's performance by overwhelming the audit log. Misconfiguration of the audit configuration files may also make it more difficult to establish and investigate events relating to an incident.
Audit
Run the following script to verify that the audit configuration files are mode 0640 or more restrictive:
#!/usr/bin/env bash
{
l_output="" l_output2="" l_perm_mask="0137"
l_maxperm="$( printf '%o' $(( 0777 & ~$l_perm_mask )) )"
while IFS= read -r -d $'\0' l_fname; do
l_mode="$( stat -Lc '%#a' "$l_fname" )"
if [ $(( $l_mode & $l_perm_mask )) -gt 0 ]; then
l_output2="$l_output2\n - file: \"$l_fname\" is mode: \"$l_mode\" (should be mode: \"$l_maxperm\" or more restrictive)"
else
l_output="$l_output\n - file: \"$l_fname\" is correctly configured to mode: \"$l_mode\""
fi
done < <(find /etc/audit/ -type f \( -name '*.conf' -o -name '*.rules' \) -print0)
if [ -z "$l_output2" ]; then
echo -e "\n- Audit Result:\n ** PASS **\n - All audit configuration files are mode: \"$l_maxperm\" or more restrictive"
else
echo -e "\n- Audit Result:\n ** FAIL **\n$l_output2"
fi
}
Remediation
Run the following command to remove more permissive mode than 0640 from the audit configuration files:
find /etc/audit/ -type f \( -name '*.conf' -o -name '*.rules' \) -exec chmod u-x,g-wx,o-rwx {} +
References
- NIST SP 800-53 Rev. 5: AU-3
CIS Controls
- v8: 3.3 Configure Data Access Control Lists
- v7: 14.6 Protect Information through Access Control Lists
MITRE ATT&CK Mappings
- Techniques: T1070, T1070.002, T1083, T1083.000
- Tactics: TA0007
- Mitigations: M1022