NVIDIA UNIX graphics driver before 295.71 and before 304.32 allows local users to write to arbitrary physical memory locations and gain privileges by modifying the VGA window using /dev/nvidia0.
http://www.openwall.com/lists/oss-security/2012/08/08/4
http://www.openwall.com/lists/oss-security/2012/08/01/1
http://security.gentoo.org/glsa/glsa-201304-01.xml
http://seclists.org/fulldisclosure/2012/Aug/76