Updated: Mozilla Firefox Two Critical Vulnerabilities

Friday, 13 May 2005 by Michel Roth

Two vulnerabilities have been discovered in Firefox, which can be exploited by malicious people to conduct cross-site scripting attacks and compromise a user's system.

1) The problem is that "IFRAME" JavaScript URLs are not properly protected from being executed in context of another URL in the history list. This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an arbitrary site.

2) Input passed to the "IconURL" parameter in "InstallTrigger.install()" is not properly verified before being used. This can be exploited to execute arbitrary JavaScript code with escalated privileges via a specially crafted JavaScript URL.

Exploit code is in the wild! At this point there is no hotfix to correct the issue but there is a workaround. Read about the workaround and more here. It is anticipated that the Mozilla Foundation will release a Firefox 1.0.4 update shortly.

Read the Secunia advisory here.

Update: the Mozilla Foundation has released the Firefox 1.0.4 update to (ao) fix the vulnerabilities mentioned.