With the November 2024 security updates, Microsoft disclosed a vulnerability (CVE-2024-43639) in the Windows Server KDC Proxy service. This is a Remote Code Execution (RCE) vulnerability with a max severity rating of Critical. If you still use Microsoft DirectAccess for remote access, you’ll want to pay close attention to this bulletin.
KDC Proxy and DirectAccess
When DirectAccess is installed and configured, the KDC Proxy Service is enabled automatically and by default. By design, DirectAccess servers are exposed to the Internet, which significantly increases the risk of this vulnerability. Organizations that have deployed DirectAccess are encouraged to update their systems immediately.
Workaround
There is no known workaround available at this time. Apply the latest security updates to mitigate this risk.