I think you're talking about the MS06-001 vulnerability (http://technet.microsoft.com/en-us/security/bulletin/ms06-001 http://technet.microsoft.com/en-us/securi

I think you're talking about the MS06-001 vulnerability (http://technet.microsoft.com/en-us/security/bulletin/ms06-001 http://technet.microsoft.com/en-us/security/bulletin/ms06-00...) with Windows Metafile (WMF) files. This is a bug in the parser for TIFF files that allows for arbitrary code execution. MS06-001 was based on removing a "feature" of the WMF format (SETABORTPROC) that allowed for arbitrary code execution for legitimate, albeit antiquated, reasons.