# Cis Ubuntu1804 V220 2 2 1

> Ensure X Window System is not installed

- Skill: `cyberstrikeus/cis-ubuntu1804-v220-2-2-1` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-ubuntu1804-v220-2-2-1`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-ubuntu1804-v220-2-2-1/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/cis-ubuntu1804-v220-2-2-1

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# 2.2.1 Ensure X Window System is not installed (Automated)

## Profile

- Level 2 - Server

## Description

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.

## Rationale

Unless your organization specifically requires graphical login access via X Windows, remove it to reduce the potential attack surface.

## Impact

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, if provided by your distribution.

## Audit Procedure

### Command Line

Verify X Windows System is not installed:

```bash
dpkg-query -s xserver-xorg &>/dev/null && echo "xserver-xorg is installed"
```

Nothing should be returned.

## Expected Result

No output (empty result).

## Remediation

### Command Line

Remove the X Windows System packages:

```bash
apt purge xserver-xorg*
```

## References

1. NIST SP 800-53 Rev. 5: CM-11

## CIS Controls

- v8: 4.8 - Uninstall or Disable Unnecessary Services on Enterprise Assets and Software
- v7: 2.6 - Address unapproved software