cis-ubuntu1204-v110-6-2

name	cis-ubuntu1204-v110-6-2
description	Ensure Avahi Server is not enabled
category	cis-os-hardening
version	1.1.0
author	cyberstrike-official
tags	["cis","ubuntu",12.04,"linux","avahi","zeroconf","mdns","attack-surface"]
cis_id	6.2
cis_benchmark	CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

6.2 Ensure Avahi Server is not enabled (Scored)

Profile Applicability

• Level 1

Description

Avahi is a free zeroconf implementation, including a system for multicast DNS/DNS-SD service discovery. Avahi allows programs to publish and discover services and hosts running on a local network with no specific configuration. For example, a user can plug a computer into a network and Avahi automatically finds printers to print to, files to look at and people to talk to, as well as network services running on the machine.

Rationale

Since servers are not normally used for printing, this service is not needed unless dependencies require it. If this is the case, disable the service to reduce the potential attack surface.

Audit Procedure

Using Command Line

Ensure no start conditions listed for avahi-daemon:

initctl show-config avahi-daemon avahi-daemon

Expected Result

No start conditions should be listed for avahi-daemon.

Remediation

Using Command Line

Remove or comment out start lines in /etc/init/avahi-daemon.conf:

sed -i 's/^start/#start/' /etc/init/avahi-daemon.conf

Default Value

Enabled by default on Ubuntu 12.04 LTS Server.

References

• CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0

Profile

Level 1 - Scored