Details

The operating system must be configured so that the user will be prompted when Ctrl-Alt-Delete key sequence is entered.

Rationale:

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

Solution

Configure the system to disable the Ctrl-Alt_Delete sequence for the command line with the following command:

# systemctl mask ctrl-alt-del.target

If GNOME is active on the system, create a database to contain the system-wide setting (if it does not already exist) with the following command:

# touch /etc/dconf/db/local.d/00-disable-CAD

Add the setting to disable the Ctrl-Alt_Delete sequence for GNOME:

[org/gnome/settings-daemon/plugins/media-keys]
logout=”

Supportive Information

The following resource is also helpful.

• https://workbench.cisecurity.org/files/3636

This security hardening control applies to the following category of controls within NIST 800-53: Configuration Management.This control applies to the following type of system Unix.

References

• 800-53|CM-6b.
• CCI|CCI-000366
• CSCv6|9.1
• CSCv7|5.1
• Rule-ID|SV-204455r603261_rule
• STIG-ID|RHEL-07-020230

Source

• Tenable.com/audits