Windows Server 2019 must not have the Telnet Client installed.

STIG ID: WN19-00-000360  |  SRG: SRG-OS-000096-GPOS-00050 | Severity: medium |  CCI: CCI-000382

Vulnerability Discussion

Unnecessary services increase the attack surface of a system. Some of these services may not support required levels of authentication or encryption or may provide unauthorized access to the system.

Check

Open "PowerShell".

Enter "Get-WindowsFeature | Where Name -eq Telnet-Client".

If "Installed State" is "Installed", this is a finding.

An Installed State of "Available" or "Removed" is not a finding.

Fix

Uninstall the "Telnet Client" feature.

Start "Server Manager".

Select the server with the feature.

Scroll down to "ROLES AND FEATURES" in the right pane.

Select "Remove Roles and Features" from the drop-down "TASKS" list.

Select the appropriate server on the "Server Selection" page and click "Next".

Deselect "Telnet Client" on the "Features" page.

Click "Next" and "Remove" as prompted.