Mozilla Firefox 4.x through 13.0 and Firefox ESR 10.x before 10.0.6 do not have the same context-menu restrictions for data: URLs as for javascript: URLs, which allows remote attackers to conduct cross-site scripting (XSS) attacks via a crafted URL.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A17037
https://bugzilla.mozilla.org/show_bug.cgi?id=734076
http://www.ubuntu.com/usn/USN-1509-2
http://www.ubuntu.com/usn/USN-1509-1
http://www.securitytracker.com/id?1027256
http://www.securityfocus.com/bid/54577
http://www.mozilla.org/security/announce/2012/mfsa2012-46.html
http://www.debian.org/security/2012/dsa-2514
http://secunia.com/advisories/49992
http://secunia.com/advisories/49979
http://secunia.com/advisories/49972
http://secunia.com/advisories/49965
http://secunia.com/advisories/49964
http://rhn.redhat.com/errata/RHSA-2012-1088.html
http://lists.opensuse.org/opensuse-security-announce/2012-07/msg00013.html
http://lists.opensuse.org/opensuse-security-announce/2012-07/msg00012.html
http://lists.opensuse.org/opensuse-security-announce/2012-07/msg00011.html