Information
This policy setting controls packet level privacy for Remote Procedure Call (RPC) incoming connections.
The recommended state for this setting is: Enabled
A security bypass vulnerability (
CVE-2021-1678 | Windows Print Spooler Spoofing Vulnerability
) exists in the way the Printer RPC binding handles authentication for the remote Winspool interface. Enabling the RPC packet level privacy setting for incoming connections enforces the server-side to increase the authentication level to minimize this vulnerability.
Solution
To establish the recommended configuration via GP, set the following UI path to Enabled :
Computer Configuration\Policies\Administrative Templates\MS Security Guide\Configure RPC packet level privacy setting for incoming connections
Note: This Group Policy path does not exist by default. An additional Group Policy template ( SecGuide.admx/adml ) is required - it is available from Microsoft at
this link
.
Impact:
None - this is default behavior.