cis-gcp-cos-2.1.2

DevOps & Security

Ensure X Window System is not installed

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I want to install this Agent Skill for this project in Codex.

Source SKILL.md: https://github.com/CyberStrikeus/CyberStrike/blob/HEAD/.cyberstrike/skill/CIS_benchmarks/Cloud_Providers/Google_Cloud_Platform/CIS_Google_Container-Optimized_OS_Benchmark_v1.2.0/cis-gcp-cos-2.1.2/SKILL.md

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2.1.2 Ensure X Window System is not installed (Automated)

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

Verify X Windows System is not installed. The following command should return empty result.

# grep xorg /etc/cos-package-info.json

Expected Result

The command should return no output, confirming that X Window System packages are not installed.

Remediation

An OS image update that does not include X Window System is required.

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	2.3 Address Unauthorized Software - Ensure that unauthorized software is either removed from use on enterprise assets or receives a documented exception. Review monthly, or more frequently.	X	X	X
v7	2.6 Address unapproved software - Ensure that unauthorized software is either removed or the inventory is updated in a timely manner	X	X	X

Profile

Level 1 - Server