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Mozilla Foundation Security Advisory 2007-01

Crashes with evidence of memory corruption (rv:

February 23, 2007
Mozilla developers and community
Firefox, SeaMonkey, Thunderbird
Fixed in
  • Firefox
  • Firefox
  • SeaMonkey 1.0.8
  • Thunderbird


As part of the Firefox and update releases we fixed several bugs to improve the stability of the product. Some of these were crashes that showed evidence of memory corruption and we presume that with enough effort at least some of these could be exploited to run arbitrary code.

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.


Upgrade to the fixed versions. Do not enable JavaScript in Thunderbird or the mail portions of SeaMonkey.


Jesse Ruderman, Martijn Wargers and Olli Pettay reported crashes in the layout engine

Tom Ferris reported a heap buffer overflow in SVG involving wide stroke widths. This flaw was introduced in Firefox 2 and does not affect earlier releases.

Brian Crowder, Igor Bukanov, Johnny Stenback, moz_bug_r_a4 and shutdown reported potential memory corruption in the JavaScript engine