| name | CIS Ubuntu 14.04 LTS - 2.3.4 Ensure telnet client is not installed |
| description | Verify that the telnet client package is not installed |
| category | cis-os-hardening |
| version | 2.1.0 |
| author | cyberstrike-official |
| tags | ["cis","ubuntu","ubuntu-14.04","level-1","scored","service-clients"] |
| cis_id | 2.3.4 |
| cis_benchmark | CIS Ubuntu Linux 14.04 LTS Benchmark v2.1.0 |
| tech_stack | ["ubuntu","linux"] |
| cwe_ids | [] |
| chains_with | [] |
| prerequisites | [] |
| severity_boost | high |
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 Procedure
Run the following command and verify telnet is not installed:
dpkg -s telnet
Expected Result
The command should indicate that the package is not installed (e.g., dpkg-query: package 'telnet' is not installed).
Remediation
Run the following command to uninstall telnet:
apt-get remove telnet
Default Value
telnet client may be installed by default.
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.
References
- CIS Controls: 3.4 Use Only Secure Channels For Remote System Administration
Profile
- Level 1 - Server
- Level 1 - Workstation
