The nsObserverList::FillObserverArray function in xpcom/ds/nsObserverList.cpp in Mozilla Firefox before 3.5.7 allows remote attackers to cause a denial of service (application crash) via a crafted web site that triggers memory consumption and an accompanying Low Memory alert dialog, and also triggers attempted removal of an observer from an empty observers array.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A8292
https://exchange.xforce.ibmcloud.com/vulnerabilities/55550
http://www.mozilla.com/en-US/firefox/3.5.7/releasenotes/
http://www.mandriva.com/security/advisories?name=MDVSA-2010:000