dom/base/nsJSEnvironment.cpp in Mozilla Firefox 3.5.x before 3.5.11 and 3.6.x before 3.6.7, Thunderbird 3.0.x before 3.0.6 and 3.1.x before 3.1.1, and SeaMonkey before 2.0.6 does not properly suppress a script's URL in certain circumstances involving a redirect and an error message, which allows remote attackers to obtain sensitive information about script parameters via a crafted HTML document, related to the window.onerror handler.