The systemd Ctrl-Alt-Delete burst key sequence in RHEL 9 must be disabled.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-257784 | RHEL-09-211045 | SV-257784r1155651_rule | CCI-002235 | high |
| Description | ||||
| 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. Satisfies: SRG-OS-000324-GPOS-00125, SRG-OS-000480-GPOS-00227 | ||||
| STIG | Date | |||
| Red Hat Enterprise Linux 9 Security Technical Implementation Guide | 2026-02-05 | |||
Details
Check Text (C-257784r1155651_chk)
Verify RHEL 9 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 (F-61449r1155650_fix)
Configure RHEL 9 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