Multiple "missing security checks" in Firefox before 1.0.3 allow remote attackers to inject arbitrary Javascript into privileged pages using the _search target of the Firefox sidebar.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11734
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A100019
https://bugzilla.mozilla.org/show_bug.cgi?id=290079
http://www.securityfocus.com/bid/13231
http://www.redhat.com/support/errata/RHSA-2005-383.html