cis-ubuntu1804-v220-2-2-10

name	cis-ubuntu1804-v220-2-2-10
description	Ensure IMAP and POP3 server are not installed
category	cis-networking
version	2.2.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-18.04","services","imap-pop3"]
cis_id	2.2.10
cis_benchmark	CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

2.2.10 Ensure IMAP and POP3 server are not installed (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 package be removed to reduce the potential attack surface.

Audit Procedure

Command Line

Run the following command to verify dovecot-imapd is not installed:

# dpkg-query -s dovecot-imapd &>/dev/null && echo "dovecot-imapd is installed"

Nothing should be returned.

Run the following command to verify dovecot-pop3d is not installed:

# dpkg-query -s dovecot-pop3d &>/dev/null && echo "dovecot-pop3d is installed"

Nothing should be returned.

Expected Result

No output (empty result) for both commands.

Remediation

Command Line

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

# apt purge dovecot-imapd dovecot-pop3d

References

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

Additional Information:

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.

CIS Controls

• v8: 4.8 - Uninstall or Disable Unnecessary Services on Enterprise Assets and Software
• v7: 9.2 - Ensure Only Approved Ports, Protocols and Services Are Running