4.1.18 Ensure the audit configuration is immutable (Scored)
Profile Applicability
- Level 2 - Server
- Level 2 - Workstation
Description
Set system audit so that audit rules cannot be modified with auditctl. Setting the flag "-e 2" forces audit to be put in immutable mode. Audit changes can only be made on system reboot.
Rationale
In immutable mode, unauthorized users cannot execute changes to the audit system to potentially hide malicious activity and then put the audit rules back. Users would most likely notice a system reboot and that could alert administrators of an attempt to make unauthorized audit changes.
Audit Procedure
Run the following command and verify output matches:
grep "^\s*[^#]" /etc/audit/audit.rules | tail -1
Expected Result
-e 2
Remediation
Add the following line to the end of the /etc/audit/audit.rules file.
-e 2
Notes: This setting will ensure reloading the auditd config to set active settings requires a system reboot.
Default Value
Not configured by default.
References
- CIS Controls v6.1 - 3 Secure Configurations for Hardware and Software on Mobile Devices, Laptops, Workstations, and Servers
- CIS Controls v6.1 - 6 Maintenance, Monitoring, and Analysis of Audit Logs
Profile
- Level 2 - Server
- Level 2 - Workstation