Buffer overflow in the JavaScript engine in Mozilla Firefox before 3.5.17 and 3.6.x before 3.6.14, and SeaMonkey before 2.0.12, might allow remote attackers to execute arbitrary code via vectors involving non-local JavaScript variables, aka an "upvarMap" issue.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A14018
https://bugzilla.mozilla.org/show_bug.cgi?id=615657
http://www.securityfocus.com/bid/46648
http://www.mozilla.org/security/announce/2011/mfsa2011-04.html
http://www.mandriva.com/security/advisories?name=MDVSA-2011:041