Privilege escalation via unverified user-writable DLL loading

Improper access control in Microsoft Windows 11 Cross Device Service allows local users to elevate privileges through DLL replacement. A user process copies and loads CrossDevice.Streaming.Source.dll from a user-modifiable location without verifying its signature, so a substituted library runs in the loading user context. Exploitation requires low-privileged local access and user interaction, and the resulting code gains the privileges of the user who loads the DLL.