Multiple elevation of privilege vulnerabilities exist when the Windows Virtual Hard Disk Driver fails to properly handle user access to certain files. An attacker who successfully exploited the vulnerabilities could manipulate files in locations not intended to be available to the user.
To exploit the vulnerabilities, an attacker would need access to the local system and the ability to execute a specially crafted application on the system.
The security update addresses the vulnerabilities by correcting how the kernel API restricts access to these files.

Further information on this exploit is available at : MS16-138