# Cis Ubuntu2004 V300 2 1 17

> Ensure web proxy server services are not in use

- Skill: `cyberstrikeus/cis-ubuntu2004-v300-2-1-17` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-ubuntu2004-v300-2-1-17`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-ubuntu2004-v300-2-1-17/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-ubuntu2004-v300-2-1-17

---


# 2.1.17 Ensure web proxy server services are not in use (Automated)

## Profile

- Level 1 - Server
- Level 1 - Workstation

## Description

Squid is a standard proxy server used in many distributions and environments.

## Rationale

If there is no need for a proxy server, it is recommended that the squid proxy software be disabled to reduce the potential attack surface.

## Audit Procedure

### Command Line

Run the following command to verify squid is not installed:

```bash
# dpkg-query -W -f='${binary:Package}\t${Status}\t${db:Status-Status}\n' squid
```

If installed, run:

```bash
# systemctl is-enabled squid.service
# systemctl is-active squid.service
```

Verify the service is not enabled and not active.

## Expected Result

squid should not be installed, or if installed, the service should be stopped and masked.

## Remediation

### Command Line

Run the following commands to stop, mask, and purge squid:

```bash
# systemctl stop squid.service
# systemctl mask squid.service
# apt purge squid
```

## Default Value

squid is not installed by default.

## References

1. NIST SP 800-53 Rev. 5: CM-7

## CIS Controls

| Controls Version | Control                                                                         | IG 1 | IG 2 | IG 3 |
| ---------------- | ------------------------------------------------------------------------------- | ---- | ---- | ---- |
| v8               | 4.8 Uninstall or Disable Unnecessary Services on Enterprise Assets and Software |      | x    | x    |
| v7               | 9.2 Ensure Only Approved Ports, Protocols and Services Are Running              |      | x    | x    |

MITRE ATT&CK Mappings: T1203, T1210, T1543, T1543.002 | TA0008 | M1042