Ubuntu OS must not have the "telnet" package installed.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
high	V-275577	SRG-OS-000074-GPOS-00042	RIIM-OS-215035	SV-275577r1147781_rule	2025-10-02	1

Description
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities are often overlooked and therefore, may remain unsecure. They increase the risk to the platform by providing additional attack vectors. Telnet is a client/server application protocol that provides an unencrypted remote access service that does not provide for the confidentiality and integrity of user passwords or the remote session. If users were allowed to log in to a system using Telnet, the privileged user passwords and communications could be compromised. Removing the "telnetd" package decreases the risk of accidental or intentional activation of the Telnet service.

Description

It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities are often overlooked and therefore, may remain unsecure. They increase the risk to the platform by providing additional attack vectors. Telnet is a client/server application protocol that provides an unencrypted remote access service that does not provide for the confidentiality and integrity of user passwords or the remote session. If users were allowed to log in to a system using Telnet, the privileged user passwords and communications could be compromised. Removing the "telnetd" package decreases the risk of accidental or intentional activation of the Telnet service.

ℹ️ Check
Verify the "telnetd" package is not installed on Ubuntu OS by using the following command: $ dpkg -l \| grep telnetd If the "telnetd" package is installed, this is a finding.

✔️ Fix
Remove the "telnetd" package by using the following command: $ sudo apt-get remove telnetd