Mozilla before 1.4.2 executes Javascript events in the context of a new page while it is being loaded, allowing it to interact with the previous page (zombie document) and enable cross-domain and cross-site scripting (XSS) attacks, as demonstrated using onmousemove events.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A937
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A874
https://exchange.xforce.ibmcloud.com/vulnerabilities/15322
http://www.securityfocus.com/bid/9747
http://www.redhat.com/support/errata/RHSA-2004-112.html
http://www.redhat.com/support/errata/RHSA-2004-110.html