The Ubuntu operating system must be configured so that audit configuration files are not write-accessible by unauthorized users.

Without the capability to restrict which roles and individuals can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events.

Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.

Verify that "/etc/audit/audit.rules", "/etc/audit/rules.d/*", and "/etc/audit/auditd.conf" files have a mode of "0640" or less permissive by using the following command:

$ sudo ls -al /etc/audit/ /etc/audit/rules.d/ 

/etc/audit/:

-rw-r----- 1 root root 804 Nov 25 11:01 auditd.conf

-rw-r----- 1 root root 9128 Dec 27 09:56 audit.rules

-rw-r----- 1 root root 9373 Dec 27 09:56 audit.rules.prev

-rw-r----- 1 root root 127 Feb 7 2018 audit-stop.rules

drwxr-x--- 2 root root 4096 Dec 27 09:56 rules.d

/etc/audit/rules.d/:

-rw-r----- 1 root root 10357 Dec 27 09:56 stig.rules

If "/etc/audit/audit.rule","/etc/audit/rules.d/*", or "/etc/audit/auditd.conf" file have a mode more permissive than "0640", this is a finding.

Configure "/etc/audit/audit.rules", "/etc/audit/rules.d/*", and "/etc/audit/auditd.conf" files to have a mode of "0640" by using the following command:

$ sudo chmod -R 0640 /etc/audit/audit*.{rules,conf} /etc/audit/rules.d/*