Vulnarability in Firefox

[crazydutch]

Please note that a vulnarability has been discovered in Firefox

Mozilla Firefox v2.0.0.11.
Prior versions and other Mozilla products may also be affected.

Mozilla Firefox displays an authentication dialog, whenever the visited web server returns 401 status code, and the "WWW-Authenticate" header. In order to specify basic authentication, the "WWW-Authenticate" header should have the value [Basic realm="XXX"] (without the brackets). The Realm value, which in this case is XXX, will be displayed in the authentication dialog window.

While Firefox does not display the characters in the "WWW-Authenticate" header Realm value after the last double-quotes ("), it fails to sanitize single-quotes (') and spaces. This makes it possible for an attacker to create a specially crafted Realm value which will look as if the authentication dialog came from a trusted web site.

Taken from here