18.9.103.1 Ensure 'Allow Remote Shell Access' is set to 'Disabled'

Information

This policy setting allows you to manage configuration of remote access to all supported shells to execute scripts and commands.

The recommended state for this setting is: Disabled.

Note: The GPME help text for this setting is incorrectly worded, implying that configuring it to Enabled will reject new Remote Shell connections, and setting it to Disabled will allow Remote Shell connections. The opposite is true (and is consistent with the title of the setting). This is a wording mistake by Microsoft in the Administrative Template.

Rationale:

Any feature is a potential avenue of attack, those that enable inbound network connections are particularly risky. Only enable the use of the Windows Remote Shell on trusted networks and when feasible employ additional controls such as IPsec.

Impact:

New Remote Shell connections are not allowed and are rejected by the server.

Note: On Server 2012 (non-R2) and newer, due to design changes in the OS after Server 2008 R2, configuring this setting as prescribed will prevent the ability to add or remove Roles and Features (even locally) via the GUI. We therefore recommend that the necessary Roles and Features be installed prior to configuring this setting on a Level 2 server. Alternatively, Roles and Features can still be added or removed using the PowerShell commands Add-WindowsFeature or Remove-WindowsFeature in the Server Manager module, even with this setting configured.

Solution

To establish the recommended configuration via GP, set the following UI path to Disabled:

Computer Configuration\Administrative Templates\Windows Components\Windows Remote Shell\Allow Remote Shell Access

Note: This Group Policy path is provided by the Group Policy template WindowsRemoteShell.admx/adml that is included with all versions of the Microsoft Windows Administrative Templates.

Default Value:

Enabled. (New Remote Shell connections are allowed.)

See Also

https://workbench.cisecurity.org/files/4022