Proof-of-concept exploit code for a privilege escalation vulnerability affecting all versions of Windows—including Vista—has been posted on a Russian hacker forum, forcing Microsoft to activate its emergency response process.
Reavey, operations manager of the Microsoft Security Response Center, confirmed that the company is "closely monitoring" the public posting, which first appeared on a Russian language forum on Dec. 15. It affects "csrss.exe," which is the main executable for the Microsoft Client/Server Runtime Server
EWeek