Mozilla Foundation Security Advisory 2008-24

Chrome script loading from fastload file

Announced
July 1, 2008
Reporter
moz_bug_r_a4
Impact
Critical
Products
Firefox, SeaMonkey, Thunderbird
Fixed in
  • Firefox 2.0.0.15
  • Firefox 3
  • SeaMonkey 1.1.10
  • Thunderbird 2.0.0.16

Description

Mozilla security researcher moz_bug_r_a4 reported that when non-priviliged XUL documents include scripts from chrome: URIs used in the browser it was possible to take advantage of the privilege level stored in the pre-compiled "fastload" file. This could allow an attacker to run arbitrary JavaScript code with chrome privileges.

Thunderbird users are not at risk when JavaScript is disabled in mail. This is the default setting and we strongly discourage users from enabling JavaScript in mail.

Workaround

Disable JavaScript until a version containing these fixes can be installed.

References