Mozilla Foundation Security Advisory 2008-42

Crashes with evidence of memory corruption (rv:

September 23, 2008
Mozilla developers and community
Firefox, SeaMonkey, Thunderbird
Fixed in
  • Firefox
  • Firefox 3.0.2
  • SeaMonkey 1.1.12
  • Thunderbird


Mozilla developers identified and fixed several stability bugs in the browser engine used in Firefox and other Mozilla-based products. Some of these crashes showed evidence of memory corruption under certain circumstances and we presume that with enough effort at least some of these could be exploited to run arbitrary code.

Drew Yao of Apple Product Security reported two crashes in Mozilla image rendering code. This vulnerability only affected Firefox 3.

David Maciejak of Fortinet's FortiGuard Global Security Research Team also reported a crash in graphics rendering which only affected Firefox 3.

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. Without further investigation we cannot rule out the possibility that for some of these an attacker might be able to prepare memory for exploitation through some means other than JavaScript such as large images.


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


Jesse Ruderman reported a crash in the layout engine.

Igor Bukanov, Philip Taylor, Georgi Guninski, and Antoine Labour reported crashes in the JavaScript engine.

Jesse Ruderman, Bob Clary, and Martijn Wargers reported crashes in the layout engine which only affected Firefox 3.

David Maciejak and Drew Yao reported crashes in graphics rendering which only affected Firefox 3.