You are here: Known Vulnerabilities in Mozilla Products (Firefox > MFSA 2006-29

Mozilla Foundation Security Advisory 2006-29

Title: Spoofing with translucent windows
Impact: Moderate
Date: April 13, 2006
Reporter: moz_bug_r_a4
Products: Firefox, SeaMonkey

Fixed in: Firefox
  SeaMonkey 1.0.1


An interaction between XUL content windows and the new faster history mechanism in Firefox 1.5 caused those windows to become translucent. This could be used to construct spoofs that could trick users into interacting with browser UI they can't see. It's possible a clever game-type presentation could persuade an unsuspicious user into some combination of actions that would result in running the attacker's code.

Firefox 1.0 and the Mozilla Suite 1.7 are not vulnerable.


Disable the faster back/forward history:

  1. Enter "about:config" into the location bar and hit Enter
  2. Enter "sessionhistory" into the "Filter" text box
  3. Double-click on browser.sessionhistory.max_total_viewers
  4. Change the default "-1" to "0" and hit the OK button


Exploit code and details embargoed during the active update period.