The systemd Ctrl-Alt-Delete burst key sequence in AlmaLinux OS 9 must be disabled.

STIG ID: ALMA-09-006620 |  SRG: SRG-OS-000324-GPOS-00125 |  Severity: high |  CCI:  | Vulnerability Id: V-269140

Vulnerability Discussion

A locally logged-on user who presses Ctrl-Alt-Delete in quick succession when at the console can reboot the system.

If accidentally pressed, as could happen in the case of a mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot.

In a graphical user environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken.

Check

Configure the system to disable the CtrlAltDelBurstAction by added or modifying the following line in the "/etc/systemd/system.conf" configuration file:

CtrlAltDelBurstAction=none

Reload the daemon for this change to take effect.

$ systemctl daemon-reexec

Fix

Verify AlmaLinux OS 9 is configured to not reboot the system when Ctrl-Alt-Delete is pressed seven times within two seconds with the following command:

$ systemd-analyze cat-config systemd/system.conf | grep -v '#' | grep CtrlAltDel

CtrlAltDelBurstAction=none

If "CtrlAltDelBurstAction" is not set to "none", is commented out, or is missing, this is a finding.