Vulnerability Discussion
If security personnel are not notified immediately when storage volume reaches 75 percent utilization, they are unable to plan for audit record storage capacity expansion.
Check
Verify RHEL 9 notifies the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity with the following command:
$ sudo grep -w space_left_action /etc/audit/auditd.conf
space_left_action = email
If the value of the "space_left_action" is not set to "email", or if the line is commented out, ask the SA to indicate how the system is providing real-time alerts to the SA and ISSO.
If there is no evidence that real-time alerts are configured on the system, this is a finding.
Fix
Configure RHEL 9 to initiate an action to notify the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity by adding/modifying the following line in the /etc/audit/auditd.conf file.
space_left_action = email