ProSecurity 1.40 Beta 2 does not properly validate certain parameters to System Service Descriptor Table (SSDT) function handlers, which allows local users to cause a denial of service (crash) and possibly gain privileges via kernel SSDT hooks for Windows Native API functions including (1) NtCreateKey, (2) NtDeleteFile, (3) NtLoadDriver, (4) NtOpenSection, and (5) NtSetSystemTime.
http://www.securityfocus.com/bid/25718
http://www.securityfocus.com/archive/1/479830/100/0/threaded
http://www.matousec.com/info/advisories/plague-in-security-software-drivers.php