Use-after-free vulnerability in win32k.sys in the kernel-mode drivers in Microsoft Windows Server 2008 R2 SP1 and Windows 7 SP1 on 64-bit platforms allows local users to gain privileges via a crafted application, aka "Win32k Use After Free Vulnerability."
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2013/ms13-101