A weakness and a vulnerability have been reported in Mozilla Firefox, which can be exploited by malicious people to cause a DoS (Denial of Service) or compromise a user's system.

1) The weakness is caused due to the improper handling of errors encountered when transforming an XML document. This can be exploited to trigger the handling of a temporary, corrupted stack variable as an evaluation context object via specially crafted XSLT code.

Successful exploitation crashes the browser. However, even though code execution has not been proven, it cannot be completely ruled out.

NOTE: Secunia normally does not classify a browser crash as a vulnerability nor issue an advisory about it. However, the potential impact of this issue may be more severe than currently believed.

2) An error in the processing of the XUL tree method "_moveToEdgeShift()" can be exploited to trigger garbage collection on objects, which are still in use.

Successful exploitation of the vulnerability allows execution of arbitrary code.

Solution
Update to version 3.0.8.

Provided and/or discovered by
1) Guido Landi
2) Nils, reported via ZDI.

Changelog
Further details available in Customer Area

Original Advisory
Mozilla:
http://www.mozilla.org/security/announce/2009/mfsa2009-12.html
http://www.mozilla.org/security/announce/2009/mfsa2009-13.html

milw0rm:
http://milw0rm.com/exploits/8285

ZDI:
http://www.zerodayinitiative.com/advisories/ZDI-09-015/

Deep Links
Links available in Customer Area