A vulnerability that is based on improper handling of exceptions by the kernel in 32 bit versions of most 
versions of Windows (including Windows 7, Vista, XP, 2000 and Server 2003/2008) can give an attacker the ability to perform such tasks as creating new accounts, installing new programs or modifying user data. The good news is that this vulnerability affects only the 32 bit versions, so if you’re running 64 bit Windows, you should be safe. So far there have been no known exploits, but Microsoft is preparing a fix for it, and in the meantime there is a workaround – disabling the NTVDM subsystem (the Windows Virtual DOS Machine). Read the security bulletin, released yesterday, to find out more:
http://www.microsoft.com/technet/security/advisory/979682.mspx
