Worst Windows security flaw yet (updated)

Michael Geary | Mon, 2006-01-02 20:18

Update: Microsoft has now released their official patch for the Windows Metafile security flaw. For detailed information, see the ISC report.

(outdated content from 2006-01-03)

In case you don’t already know about it, the new Windows Metafile security flaw is a nasty one. Do not wait for the Microsoft patch due next week. Protect your system now with Ilfak Guilfanov’s unofficial patch. After installing the patch, you can test your system to confirm that the bug is fixed. (Click on the Kevin Gennuso link on that page to open a .wmf file that attempts to start calc.exe. If you get a normal Windows Picture and Fax Viewer window instead of calc.exe, you are good to go.)

After Microsoft’s official patch is released, you can uninstall the unofficial patch.

I didn’t review the code for the unofficial patch, but people who did review it describe how it works in the WMF FAQ. The patch works just the way I would have coded it myself.

The FAQ also recommends unregistering shimgvw.dll in addition to the patch. I don’t think this is necessary, but it wouldn’t hurt.