firefox is vulnerable to arbitrary code execution. An attacker is able to exploit the vulnerability within the OS font implementation to execute arbitrary code using malformed OpenType fonts by verifying the font file prior to use.
code.google.com/p/ots/
lists.fedoraproject.org/pipermail/package-announce/2010-December/052022.html
lists.fedoraproject.org/pipermail/package-announce/2010-December/052032.html
lists.fedoraproject.org/pipermail/package-announce/2010-December/052110.html
lists.fedoraproject.org/pipermail/package-announce/2010-December/052220.html
lists.fedoraproject.org/pipermail/package-announce/2010-December/052502.html
lists.fedoraproject.org/pipermail/package-announce/2010-December/052504.html
lists.opensuse.org/opensuse-security-announce/2011-01/msg00002.html
secunia.com/advisories/42716
secunia.com/advisories/42818
support.avaya.com/css/P8/documents/100124650
www.mandriva.com/security/advisories?name=MDVSA-2010:251
www.mandriva.com/security/advisories?name=MDVSA-2010:258
www.mozilla.org/security/announce/2010/mfsa2010-78.html
www.mozilla.org/security/known-vulnerabilities/firefox36.html#firefox3.6.13
www.redhat.com/support/errata/RHSA-2010-0966.html
www.redhat.com/support/errata/RHSA-2010-0969.html
www.securityfocus.com/bid/45352
www.securitytracker.com/id?1024846
www.securitytracker.com/id?1024848
www.ubuntu.com/usn/USN-1019-1
www.ubuntu.com/usn/USN-1020-1
www.vupen.com/english/advisories/2011/0030
access.redhat.com/errata/RHSA-2010:0966
access.redhat.com/security/updates/classification/#critical
bugzilla.mozilla.org/show_bug.cgi?id=527276
bugzilla.redhat.com/show_bug.cgi?id=660420
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12533