Title

RHEL 9 must not have the telnet-server package installed. (Cat II impact)

Discussion

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. The telnet service provides an unencrypted remote access service, which does not provide for the confidentiality and integrity of user passwords or the remote session. If a privileged user were to login using this service, the privileged user password could be compromised. Removing the "telnet-server" package decreases the risk of accidental (or intentional) activation of the telnet service.

Check Content

Verify that the telnet-server package is not installed with the following command: $ dnf list --installed telnet-server Error: No matching Packages to list If the "telnet-server" package is installed, this is a finding.

Fix Text

Remove the telnet-server package with the following command: $ sudo dnf remove telnet-server

Additional Identifiers

Rule ID: SV-257831r1044898_rule

Vulnerability ID: V-257831

Group Title: SRG-OS-000095-GPOS-00049

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.