The host is installed with Microsoft Windows XP or Windows server 2003 or Windows server 2008 or Windows Vista or Windows 7 or Windows server 2008 R2 and is prone to memory corruption vulnerability. A flaw is present in Client/Server Run-time Subsystem (CSRSS) where a NULL pointer is passed without validation to a function in the CSRSS. Successful exploitation allows remote attacker to execute arbitrary code in the system context.