Mozilla Foundation Security Advisory 2008-50
Title: Crash and remote code execution via proto tampering
Impact: Critical
Announced: November 12, 2008
Reporter: Jesse Ruderman
Products: Firefox, Thunderbird, SeaMonkey
Fixed in: Firefox 3.0.2
Firefox 2.0.0.18
Thunderbird 2.0.0.18
SeaMonkey 1.1.13
Description
Mozilla developer Jesse Ruderman demonstrated that by tampering with the window.proto.proto object, one can cause the browser to place a lock on a non-native object, leading to a crash. Although we have not demonstrated such control, a determined attacker might be able to exploit this crash to run arbitrary code on a victim's computer.
Thunderbird shares the browser engine with Firefox and could be vulnerable if JavaScript were to be enabled in mail. This is not the default setting and we strongly discourage users from running JavaScript in mail.
Workaround
Disable JavaScript until a version containing these fixes can be installed.
References
* https://bugzilla.mozilla.org/show_bug.cgi?id=436741
* CVE-2008-5014