Cross-site scripting using .valueOf.call()
moz_bug_r_a4 discovered that .valueOf.call() and .valueOf.apply() when
called with no arguments were returning the Object class prototype rather
than the caller's global window object. When called on a reachable property
of another window this provides a hook to get around the same-origin
protection, allowing an attacker to inject script into another window.
Cross-site script injection can be used to steal confidential data such as
cookies or passwords, or perform actions on the user's behalf. It can also
be used to alter the content of the other window which could be used to fool
a user into trusting bogus information or downloaded content.
This issue also affects FC4
These issues have been resolved in FEDORA-2006-411 for FC5 and FEDORA-2006-410