UBTU-24-900960 Ubuntu 24.04 LTS must immediately notify the system administrator (SA) and information system security officer (ISSO) (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity.
All changes in this version
Maps to AU-5(1) via CCI-001855
Title
Ubuntu 24.04 LTS must immediately notify the system administrator (SA) and information system security officer (ISSO) (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity.
Control
Verify Ubuntu 24.04 LTS 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: Note: If the space_left_action is set to "email", an email package must be available. $ sudo grep ^space_left_action /etc/audit/auditd.conf space_left_action email $ sudo grep ^space_left /etc/audit/auditd.conf space_left 250000 If the "space_left" parameter is set to "syslog", is missing, set to blanks, or set to a value less than 25 percent of the space free in the allocated audit record storage, this is a finding. If the "space_left_action" parameter is missing or set to blanks, this is a finding. If the "space_left_action" is set to "email", check the value of the "action_mail_acct" parameter with the following command: $ sudo grep ^action_mail_acct /etc/audit/auditd.conf action_mail_acct root@localhost The "action_mail_acct" parameter, if missing, defaults to "root". If the "action_mail_acct parameter" is not set to the email address of the SA(s) and/or ISSO, this is a finding. If the "space_left_action" is set to "exec", the system executes a designated script. If this script informs the SA of the event, this is not a finding.
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.
Related controls
CCI-001855
Fix
Edit "/etc/audit/auditd.conf" and set the "space_left_action" parameter to "exec" or "email". If the "space_left_action" parameter is set to "email", set the "action_mail_acct" parameter to an email address for the SA and ISSO. If the "space_left_action" parameter is set to "exec", ensure the command being executed notifies the SA and ISSO. Edit "/etc/audit/auditd.conf" and set the "space_left" parameter to be at least 25 percent of the repository maximum audit record storage capacity.