__Summary

Even though Firefox 1.0.1 patched one of the key bugs behind my 
firescrolling exploit (the ability of plugins to load chrome files in a 
hidden frame) the ability to hijack a drag and drop operation and open a 
privileged xul file is still available.

The demo opens "chrome://global/content/alerts/alert.xul" when dragging the 
scrollbar the first time. This XUL file automaticly runs an inline script to 
turn the window into a tray notification alert. This demo is just an example 
of an annoying usage, but if the browser or an extension contains an inline 
script that uses an eval/setTimeout with a parameter an attacker can 
influence it turns into an arbitrary code execution bug. Also update or 
uninstall scripts could be a valuable target. I doubt most extension 
developers think about problems that could occure if a XUL file in their 
extensions is opened directly.

__Proof-of-Concept

http://www.mikx.de/firescrolling2/

__Status

The bug is fixed in Firefox 1.0.2.

2005-03-09 Vendor informed (bugzilla.mozilla.org #285438)
2005-03-11 Vendor confirmed bug
2005-03-23 Vendor published fixed version and advisory
2005-03-24 Public disclosure

The Common Vulnerabilities and Exposures project (cve.mitre.org) has 
assigned the name CAN-2005-0401 to this issue.

__Affected Software

Tested with Firefox 1.0.1

__Contact Informations

Michael Krax <mikx@mikx.de>
http://www.mikx.de/?p=12

mikx