Launching local programs through FileType handler

Issue
We are currently investigating an issue on Windows XP, where some urls for “web” protocols that contain %00 launch the wrong handler and appear to be able to launch local programs, with limited argument passing.

Impact
The impact to users is unknown at this point in time. We are working to verify this and in the meantime, advise users to be cautious when browsing unknown sites.

Status
We are currently working on a fix. You can follow our work and process at: https://bugzilla.mozilla.org/show_bug.cgi?id=389580

Credit
Billy Rios and Nate McFeters posted details about this issue publicly at:http://xs-sniper.com/blog/remote-command-exec-firefox-2005/