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 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.

Check

Note: If a graphical user interface is not installed, this requirement is Not Applicable.

Verify the SUSE operating system is not configured to reboot the system when Ctrl-Alt-Delete is pressed in the graphical user interface.

Check that the dconf setting was disabled to allow the Ctrl-Alt-Delete sequence in the graphical user interface with the following command:

Check the default logout key sequence:

> sudo gsettings get org.gnome.settings-daemon.plugins.media-keys logout
''

Check that the value is not writable and cannot be changed by the user:

> sudo gsettings writable org.gnome.settings-daemon.plugins.media-keys logout
false

If the logout value is not [''] and the writable status is not false, this is a finding.

Fix

Configure the system to disable the Ctrl-Alt-Delete sequence for the graphical user interface.

Create a database to contain the system-wide setting (if it does not already exist) with the following steps:

1. Create a user profile and with the listed content:

/etc/dconf/profile/user
user-db:user
system-db:local

2. Create the following directories:

> sudo mkdir -p /etc/dconf/db/local.d/
> sudo mkdir -p /etc/dconf/db/local.d/locks/

3. Add the following files with the listed content:

/etc/dconf/db/local.d/01-fips-settings
[org/gnome/settings-daemon/plugins/media-keys]
logout=''

/etc/dconf/db/local.d/locks/01-fips-locks
/org/gnome/settings-daemon/plugins/media-keys/logout

4. Update the dconf database:

> sudo dconf update