Information
The X Windows 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 desktops where users login, but not on servers where users typically do not login.
Rationale:
Unless your organization specifically requires graphical login access via X Windows, remove it to reduce the potential attack surface.
Solution
Edit /etc/inittab set default runlevel as follows:
s/:5:/:3:/
Uninstall the X Windows System:
# yum groupremove 'X Window System'
Default Value:
OS Default: N/A