firefox is vulnerable to arbitrary code execution. The vulnerability exists as a flaw was found in the way Firefox handled certain JavaScript cross-domain requests. If malicious content generated a large number of cross-domain JavaScript requests, it could cause Firefox to execute arbitrary code with the privileges of the user running Firefox.
blogs.oracle.com/sunsecurity/entry/multiple_vulnerabilities_in_thunderbird
downloads.avaya.com/css/P8/documents/100144158
www.debian.org/security/2011/dsa-2227
www.debian.org/security/2011/dsa-2228
www.debian.org/security/2011/dsa-2235
www.mandriva.com/security/advisories?name=MDVSA-2011:079
www.mandriva.com/security/advisories?name=MDVSA-2011:080
www.mozilla.org/security/announce/2011/mfsa2011-12.html
www.mozilla.org/security/known-vulnerabilities/firefox36.html#firefox3.6.17
www.securityfocus.com/bid/47656
access.redhat.com/errata/RHSA-2011:0471
access.redhat.com/security/updates/classification/#critical
bugzilla.mozilla.org/show_bug.cgi?id=644069
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A14065