The systemd Ctrl-Alt-Delete burst key sequence in RHEL 8 must be disabled.

STIG ID: RHEL-08-040172  |  SRG: SRG-OS-000480-GPOS-00227 | Severity: high |  CCI: CCI-000366

Vulnerability Discussion

A locally logged-on user who presses Ctrl-Alt-Delete 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

Verify RHEL 8 is not configured to reboot the system when Ctrl-Alt-Delete is pressed seven times within two seconds with the following command:

$ sudo grep -i ctrl /etc/systemd/system.conf

CtrlAltDelBurstAction=none

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

Fix

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.

$ sudo systemctl daemon-reload