You are here: Known Vulnerabilities in Mozilla Products (Firefox > MFSA 2008-19

Mozilla Foundation Security Advisory 2008-19

Title: XUL popup spoofing variant (cross-tab popups)
Impact: High
Announced: March 25, 2008
Reporter: Chris Thomas
Products: Firefox, SeaMonkey

Fixed in: Firefox
  SeaMonkey 1.1.9


Mozilla contributor Chris Thomas demonstrated that it was possible to have a background tab create a borderless XUL pop-up in front of the active tab in the user's browser. This technique could be used by an attacker to spoof form elements such as a login prompt for a site opened in a different tab and steal the user's login credentials for that site.