Information
The X Window System provides a Graphical User Interface (GUI) where users can have multiple windows in which to run programs and various add on. The X Windows system is typically used on workstations where users login, but not on servers where users typically do not login.
Unless your organization specifically requires graphical login access via X Windows, remove it to reduce the potential attack surface.
Solution
- IF - a Graphical Desktop Manager or X-Windows server is not required and approved by local site policy:
Run the following command to remove the X Windows Server package:
# apt purge xserver-common
Impact:
If a Graphical Desktop Manager (GDM) is in use on the system, there may be a dependency on the xorg-x11-server-common package. If the GDM is required and approved by local site policy, the package should not be removed.
Many Linux systems run applications which require a Java runtime. Some Linux Java packages have a dependency on specific X Windows xorg-x11-fonts. One workaround to avoid this dependency is to use the "headless" Java packages for your specific Java runtime.