Mozilla Foundation Security Advisory 2012-84

Spoofing and script injection through location.hash

October 9, 2012
Mariusz Mlynski
Firefox, Firefox ESR, SeaMonkey, Thunderbird, Thunderbird ESR
Fixed in
  • Firefox 16
  • Firefox ESR 10.0.8
  • SeaMonkey 2.13
  • Thunderbird 16
  • Thunderbird ESR 10.0.8


Security researcher Mariusz Mlynski reported an issue with spoofing of the location property. In this issue, writes to location.hash can be used in concert with scripted history navigation to cause a specific website to be loaded into the history object. The baseURI can then be changed to this stored site, allowing an attacker to inject a script or intercept posted data posted to a location specified with a relative path.

In general these flaws cannot be exploited through email in the Thunderbird and SeaMonkey products because scripting is disabled, but are potentially a risk in browser or browser-like contexts in those products.