Privilege escalation 0-day in almost all Windows versions

Today proof of concept code (source code, with a compiled binary) of a 0-day privilege escalation vulnerability in almost all Windows operating system versions (Windows XP, Vista, 7, Server 2008 ...) has been posted on a popular programming web site. The vulnerability is a buffer overflow in kernel (win32k.sys) and, due to its nature allows an attacker to bypass User Access Control (UAC) on