Mozilla Firefox 2.0.0.5, Thunderbird 2.0.0.5 and before 1.5.0.13, and SeaMonkey 1.1.3 allows remote attackers to conduct cross-site scripting (XSS) attacks with chrome privileges via an addon that inserts a (1) javascript: or (2) data: link into an about:blank document loaded by chrome via (a) the window.open function or (b) a content.location assignment, aka "Cross Context Scripting." NOTE: this issue is caused by a CVE-2007-3089 regression.