InformationThis policy setting specifies whether to prevent the redirection of data to client COM ports from the remote computer in a Remote Desktop Services session.
The recommended state for this setting is: Enabled.
In a more security-sensitive environment, it is desirable to reduce the possible attack surface. The need for COM port redirection within a Remote Desktop session is very rare, so makes sense to reduce the number of unexpected avenues for data exfiltration and/or malicious code transfer.
Users in a Remote Desktop Services session will not be able to redirect server data to local (client) COM ports.
SolutionTo establish the recommended configuration via GP, set the following UI path to Enabled:
Computer Configuration\Policies\Administrative Templates\Windows Components\Remote Desktop Services\Remote Desktop Session Host\Device and Resource Redirection\Do not allow COM port redirection
Note: This Group Policy path is provided by the Group Policy template TerminalServer.admx/adml that is included with all versions of the Microsoft Windows Administrative Templates.
Disabled. (Remote Desktop Services allows COM port redirection.)