CVE-2012-1893 — Improper Input Validation in Microsoft Windows Server 2008

win32k.sys in the kernel-mode drivers in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 does not properly validate callback parameters during creation of a hook procedure, which allows local users to gain privileges via a crafted application, aka "Win32k Incorrect Type Handling Vulnerability."