1.7.3 Ensure GDM disable-user-list option is enabled

Information

GDM is the GNOME Display Manager which handles graphical login for GNOME based systems.

The disable-user-list option controls if a list of users is displayed on the login screen

Displaying the user list eliminates half of the Userid/Password equation that an unauthorized person would need to log on.

Solution

- IF - A user profile exists run the following command to enable the disable-user-list :

# gsettings set org.gnome.login-screen disable-user-list true

Note:

- gsettings commands in this section MUST be done from a command window on a graphical desktop or an error will be returned.
- The system must be restarted after all gsettings configurations have been set in order for CIS-CAT Assessor to appropriately assess.

- OR/IF - A user profile does not exist:

- Create or edit the gdm profile in /etc/dconf/profile/gdm with the following lines:

user-db:user
system-db:gdm
file-db:/usr/share/gdm/greeter-dconf-defaults

Note: gdm is the name of a dconf database.

- Create a gdm keyfile for machine-wide settings in /etc/dconf/db/gdm.d/00-login-screen :

[org/gnome/login-screen]
# Do not show the user list
disable-user-list=true
- Update the system databases:

# dconf update

Note: When the user profile is created or changed, the user will need to log out and log in again before the changes will be applied.

See Also

https://workbench.cisecurity.org/benchmarks/24330

Item Details

Category: CONFIGURATION MANAGEMENT, IDENTIFICATION AND AUTHENTICATION

References: 800-53|CM-1, 800-53|CM-2, 800-53|CM-6, 800-53|CM-7, 800-53|IA-5

Plugin: Unix

Control ID: f7c24bb1368849c1f070a3f84d3d3ec7489e944c544e0ec4583f178c411133d8