cyberstrikeus 2.2.4 Ensure telnet client is not installed (Automated)
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.
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.
Audit Procedure
Command Line
Verify telnet is not installed. Use the following command to provide the needed information:
dpkg -s telnet | grep -E '(Status:|not installed)'
Expected Result
dpkg-query: package 'telnet' is not installed and no information is available
Remediation
Command Line
Uninstall telnet:
apt purge telnet
Default Value
telnet is not installed on minimal server installations.
References
- CIS Controls v7 - 4.5 Use Multifactor Authentication For All Administrative Access
Profile
- Level 1 - Server
- Level 1 - Workstation