Title

The systemd Ctrl-Alt-Delete burst key sequence in RHEL 8 must be disabled. (Cat I impact)

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 Content

Verify RHEL 8 is configured to not reboot the system when Ctrl-Alt-Delete is pressed seven times within two seconds with the following command: $ sudo grep -iR CtrlAltDelBurstAction /etc/systemd/system* /etc/systemd/system.conf.d/55-CtrlAltDel-BurstAction:CtrlAltDelBurstAction=none If the "CtrlAltDelBurstAction" is not set to "none", commented out, or is missing, this is a finding.

Fix Text

Configure RHEL 8 to disable the CtrlAltDelBurstAction by adding it to a drop file in a "/etc/systemd/system.conf.d/" configuration file: If no drop file exists, create one with the following command: $ sudo mkdir -p /etc/systemd/system.conf.d && sudo vi /etc/systemd/system.conf.d/55-CtrlAltDel-BurstAction Edit the file to contain the setting by adding the following text: CtrlAltDelBurstAction=none Reload the daemon for this change to take effect. $ sudo systemctl daemon-reload

Additional Identifiers

Rule ID: SV-230531r1155396_rule

Vulnerability ID: V-230531

Group Title: SRG-OS-000480-GPOS-00227

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