cis-ubuntu2004-v300-2-1-17

name	cis-ubuntu2004-v300-2-1-17
description	Ensure web proxy server services are not in use
category	cis-networking
version	3.0.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-20.04","services"]
cis_id	2.1.17
cis_benchmark	CIS Ubuntu Linux 20.04 LTS Benchmark v3.0.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

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:

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

If installed, run:

# 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:

# 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