cis-ubuntu1604-v200-2-1-11

name	cis-ubuntu1604-v200-2-1-11
description	Ensure IMAP and POP3 server are not installed
category	cis-networking
version	2.0.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-16.04","services"]
cis_id	2.1.11
cis_benchmark	CIS Ubuntu Linux 16.04 LTS Benchmark v2.0.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

2.1.11 Ensure IMAP and POP3 server are not installed (Automated)

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 package be removed 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 -s dovecot-imapd dovecot-pop3d | grep -E '(Status:|not installed)'

Expected Result

dpkg-query: package 'dovecot-imapd' is not installed and no information is available
dpkg-query: package 'dovecot-pop3d' is not installed and no information is available

Remediation

Command Line

Run one of the following commands to remove dovecot-imapd and dovecot-pop3d:

apt purge dovecot-imapd dovecot-pop3d

Default Value

dovecot-imapd and dovecot-pop3d are not installed on minimal server installations. Several IMAP/POP3 servers exist and can use other service names. courier-imap and cyrus-imap are example services that provide a mail server. These and other services should also be audited.

References

1. CIS Controls v7 - 9.2 Ensure Only Approved Ports, Protocols and Services Are Running

Profile

• Level 1 - Server
• Level 1 - Workstation