|Mozilla Firefox before 3.0.9, Thunderbird, and SeaMonkey do not
properly implement the Same Origin Policy for (1) XMLHttpRequest,
involving a mismatch for a document's principal, and (2)
XPCNativeWrapper.toString, involving an incorrect __proto__ scope,
which allows remote attackers to conduct cross-site scripting (XSS)
attacks and possibly other attacks via a crafted document.