cis-ubuntu2004-v300-2-1-4

name	cis-ubuntu2004-v300-2-1-4
description	Ensure dns 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	2.1.4
cis_benchmark	CIS Ubuntu Linux 20.04 LTS Benchmark v3.0.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

2.1.4 Ensure dns server services are not in use (Automated)

Profile

• Level 1 - Server
• Level 1 - Workstation

Description

The Domain Name System (DNS) is a hierarchical naming system that maps names to IP addresses for computers, services and other resources connected to a network.

Rationale

Unless a system is specifically designated to act as a DNS server, it is recommended that the service be disabled to reduce the potential attack surface.

Audit Procedure

Command Line

Run the following command to verify bind9 is not installed:

# dpkg-query -W -f='${binary:Package}\t${Status}\t${db:Status-Status}\n' bind9

If installed, run:

# systemctl is-enabled named.service
# systemctl is-active named.service

Verify the service is not enabled and not active.

Expected Result

bind9 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 bind9:

# systemctl stop named.service
# systemctl mask named.service
# apt purge bind9

Default Value

bind9 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