Table of Contents

2.3.4 Ensure telnet client is not installed (Scored)

Profile Applicability

Level 1 - Server
Level 1 - Workstation 

Description

The telnet package contains the telnet client, which allows users to start connections to other systems via the telnet protocol.

Rationale

The telnet protocol is insecure and unencrypted. The use of an unencrypted transmission medium could allow an unauthorized user to steal credentials. The ssh package provides an encrypted session and stronger security and is included in most Linux distributions.

Audit

Run the following commands to verify telnet is not installed:

dpkg -s telnet

Remediation

Run the following command to uninstall telnet:

apt-get remove telnet

Impact

Many insecure service clients are used as troubleshooting tools and in testing environments. Uninstalling them can inhibit capability to test and troubleshoot. If they are required it is advisable to remove the clients after use to prevent accidental or intentional misuse.