firefox is vulnerable to arbitrary javascript code execution. The vulnerability exists as a flaw was found in Firefox that could allow an applet to generate a drag and drop action from a mouse click. Such an action could be used to execute arbitrary JavaScript with the privileges of the user running Firefox.
lists.opensuse.org/opensuse-security-announce/2010-06/msg00001.html
secunia.com/advisories/39136
secunia.com/advisories/39240
secunia.com/advisories/39243
secunia.com/advisories/39308
secunia.com/advisories/39397
securitytracker.com/id?1023776
ubuntu.com/usn/usn-921-1
www.debian.org/security/2010/dsa-2027
www.mandriva.com/security/advisories?name=MDVSA-2010:070
www.mozilla.org/security/announce/2010/mfsa2010-20.html
www.mozilla.org/security/known-vulnerabilities/firefox30.html#firefox3.0.19
www.redhat.com/security/updates/classification/#critical
www.redhat.com/support/errata/RHSA-2010-0332.html
www.vupen.com/english/advisories/2010/0748
www.vupen.com/english/advisories/2010/0764
www.vupen.com/english/advisories/2010/0781
www.vupen.com/english/advisories/2010/0849
access.redhat.com/errata/RHSA-2010:0332
bugzilla.mozilla.org/show_bug.cgi?id=546909
exchange.xforce.ibmcloud.com/vulnerabilities/57391
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10460
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6975