cis-ubuntu1804-v220-2-3-2

name	cis-ubuntu1804-v220-2-3-2
description	Ensure rsh client is not installed
category	cis-networking
version	2.2.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-18.04","services","rsh-client"]
cis_id	2.3.2
cis_benchmark	CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

2.3.2 Ensure rsh client is not installed (Automated)

Profile

• Level 1 - Server
• Level 1 - Workstation

Description

The rsh-client package contains the client commands for the rsh services.

Rationale

These legacy clients contain numerous security exposures and have been replaced with the more secure SSH package. Even if the server is removed, it is best to ensure the clients are also removed to prevent users from inadvertently attempting to use these commands and therefore exposing their credentials. Note that removing the rsh-client package removes the clients for rsh, rcp and rlogin.

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 rsh-client is not installed. Use the following command to provide the needed information:

# dpkg-query -s rsh-client &>/dev/null && echo "rsh-client is installed"

Nothing should be returned.

Expected Result

No output (empty result).

Remediation

Command Line

Uninstall rsh:

# apt purge rsh-client

References

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

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