Mozilla Foundation Security Advisory 2005-55

Title: XHTML node spoofing
Severity: High
Reporter: moz_bug_r_a4
Products: Firefox, Mozilla Suite

Fixed in: Firefox 1.0.5
Mozilla Suite 1.7.9

Description

Parts of the browser UI relied too much on DOM node names without taking different namespaces into account and verifying that the node was really of the expected type. An XHTML document could be used, for example, to create fake elements with content-defined properties that will be accessed as if they were the trusted built-in properties of the expected HTML elements.

The severity of the vulnerability would depend on what the attacker could convince the victim to do, but could result in executing user-supplied script with elevated "chrome" privileges. This could be used to install malicious software on the victim's machine.

Workaround

Disable Javascript.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=298892