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 with the following command:

$ sudo systemctl status ctrl-alt-del.target

ctrl-alt-del.target
Loaded: masked (Reason: Unit ctrl-alt-del.target is masked.)
Active: inactive (dead)

If the "ctrl-alt-del.target" is loaded and not masked, this is a finding.

Fix

Configure the system to disable the Ctrl-Alt-Delete sequence for the command line with the following commands:

$ sudo systemctl disable ctrl-alt-del.target

$ sudo systemctl mask ctrl-alt-del.target

Created symlink /etc/systemd/system/ctrl-alt-del.target -> /dev/null

Reload the daemon for this change to take effect.

$ sudo systemctl daemon-reload