All .Xauthority files must have mode 0600 or less permissive.

.Xauthority files ensure the user is authorized to access the specific X Windows host. Excessive permissions may permit unauthorized modification of these files, which could lead to Denial of Service to authorized access or allow unauthorized access to be obtained.

If X Display Manager (XDM) is not used on the system, this is not applicable.

Determine if XDM is running.

Procedure: # ps -ef | grep xdm

Check the file permissions for the .Xauthority files in the home directories of users of X. Procedure: # cd ~<X user> # ls -lL .Xauthority

If the file mode is more permissive than 0600, this is finding.

Change the mode of the .Xauthority files.

Procedure: # chmod 0600 .Xauthority