Microsoft is warning Windows XP and Server 2003 users that exploit code has been posted online showing attackers how to break into these operating systems remotely via a newly-discovered security flaw.
The security flaw has to do with a weakness in the way the Windows Help and Support Center processes links. Both Windows XP and Server 2003 retrieve help and support information from a fixed set of Web pages that are included on a whitelist maintained by Windows. But Google security research Tavis Ormandy discovered that it was possible to add URLs to that whitelist.