xulrunner is vulnerable to arbitrary code execution. The vulnerability exists as a web page containing malicious content could cause Firefox to crash or, potentially, execute arbitrary code as the user running Firefox.
lists.opensuse.org/opensuse-security-announce/2009-05/msg00000.html
secunia.com/advisories/34758
secunia.com/advisories/34780
secunia.com/advisories/34843
secunia.com/advisories/34894
secunia.com/advisories/35042
secunia.com/advisories/35065
secunia.com/advisories/35602
sunsolve.sun.com/search/document.do?assetkey=1-66-264308-1
www.debian.org/security/2009/dsa-1797
www.debian.org/security/2009/dsa-1830
www.mandriva.com/security/advisories?name=MDVSA-2009:111
www.mandriva.com/security/advisories?name=MDVSA-2009:141
www.mozilla.org/security/announce/2009/mfsa2009-14.html
www.mozilla.org/security/known-vulnerabilities/firefox30.html#firefox3.0.9
www.redhat.com/security/updates/classification/#critical
www.redhat.com/support/errata/RHSA-2009-0436.html
www.securityfocus.com/bid/34656
www.securitytracker.com/id?1022090
www.slackware.com/security/viewer.php?l=slackware-security&y=2009&m=slackware-security.454275
www.vupen.com/english/advisories/2009/1125
access.redhat.com/errata/RHSA-2009:0436
bugzilla.mozilla.org/show_bug.cgi?id=428113
bugzilla.mozilla.org/show_bug.cgi?id=431260
bugzilla.mozilla.org/show_bug.cgi?id=432114
bugzilla.mozilla.org/show_bug.cgi?id=454276
bugzilla.mozilla.org/show_bug.cgi?id=461053
bugzilla.mozilla.org/show_bug.cgi?id=462517
bugzilla.mozilla.org/show_bug.cgi?id=467881
bugzilla.mozilla.org/show_bug.cgi?id=477775
bugzilla.mozilla.org/show_bug.cgi?id=483444
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10106
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5527
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6070
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6170
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A7030
usn.ubuntu.com/764-1/
www.redhat.com/archives/fedora-package-announce/2009-April/msg00683.html