Secunia

Some vulnerabilities have been reported in Firefox 3, which can be exploited by malicious people to bypass certain security restrictions, potentially conduct spoofing attacks, or compromise a user's system.

1) A vulnerability can be exploited to launch e.g. "file" or "chrome:" URIs in Firefox.

For more information see:
SA31120

2) Input passed to XUL based error pages is not properly sanitised before being returned to a user and can be exploited to e.g. conduct spoofing attacks.

In combination with vulnerability #1 this can be exploited to inject arbitrary script code and execute arbitrary code in "chrome" context, but requires that a specially crafted URI is passed to Firefox and that Firefox is not running.

The vulnerabilities are reported in versions prior to 3.0.1.

Solution
Update to version 3.0.1.
Further details available in Customer Area

Provided and/or discovered by
The vendor credits:
1) Billy Rios
2) Ben Turner and Dan Veditz (Mozilla developers)

Changelog
Further details available in Customer Area

Original Advisory
MFSA 2008-35:
http://www.mozilla.org/security/announce/2008/mfsa2008-35.html

Other references
Further details available in Customer Area

Deep Links
Links available in Customer Area