cis-ubuntu2004-v300-2-1-8

name	cis-ubuntu2004-v300-2-1-8
description	Ensure message access 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	2.1.8
cis_benchmark	CIS Ubuntu Linux 20.04 LTS Benchmark v3.0.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

2.1.8 Ensure message access server services are not in use (Automated)

Profile

• Level 1 - Server
• Level 1 - Workstation

Description

dovecot-imapd and dovecot-pop3d are an open source IMAP and POP3 server for Linux based systems.

Rationale

Unless POP3 and/or IMAP servers are to be provided by this system, it is recommended that the services be disabled to reduce the potential attack surface.

Audit Procedure

Command Line

Run the following command to verify dovecot-imapd and dovecot-pop3d are not installed:

# dpkg-query -W -f='${binary:Package}\t${Status}\t${db:Status-Status}\n' dovecot-imapd dovecot-pop3d

If installed, run:

# systemctl is-enabled dovecot.socket dovecot.service
# systemctl is-active dovecot.socket dovecot.service

Verify the services are not enabled and not active.

Expected Result

dovecot-imapd and dovecot-pop3d should not be installed, or if installed, the services should be stopped and masked.

Remediation

Command Line

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

# systemctl stop dovecot.socket dovecot.service
# systemctl mask dovecot.socket dovecot.service
# apt purge dovecot-imapd dovecot-pop3d

Default Value

dovecot-imapd and dovecot-pop3d are 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