An elevation of privilege vulnerability exists when Windows improperly handles calls to Advanced Local Procedure Call (ALPC).An attacker who successfully exploited this vulnerability could run arbitrary code in the security context of the local system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

The specific flaw exists within the implementation of the 0x138bd IOCTL in the webvrpcs process. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this functionality to execute code under the context of Administrator.