The ScribeFire Firefox extension provides an interface for users to post to their blogs from any website. It allows users to drag images from a website into the editing pane, which publishes that image as part of their blog post.
ScribeFire is vulnerable to multiple injection vulnerabilities which can be exploited through a malicious image. Cross-Site Scripting and HTML injection vulnerabilities were discovered within the DOM event handlers of tags. ScribeFire directly evaluates remotely supplied content, within the privileged chrome context. This can allow an image on a website to exploit users who share it, and may lead to the complete compromise of the host.
Vulnerable Systems:
* ScribeFire Firefox Extension version 3.4.1
Immune Systems:
* ScribeFire Firefox Extension version 3.4.2
This vulnerability can be exploited in several ways. As the injection point is in the chrome privileged browser zone, it is possible to bypass Same Origin Policy (SOP) protections, and also access Mozilla built-in XPCOM components. XPCOM components can be used to read and write from the file system, as well as execute arbitrary commands, steal stored passwords, or modify other Firefox extensions.
