Mozilla Foundation Security Advisory 2008-34


Mozilla Foundation Security Advisory 2008-34 Title: Remote code execution by overflowing CSS reference counter Impact: Critical Announced: July 15, 2008 Reporter: TippingPoint Zero Day Initiative Products: Firefox, Thunderbird, SeaMonkey Fixed in: Firefox 3.0.1 Firefox Thunderbird SeaMonkey 1.1.11 Description An anonymous researcher, via TippingPoint's Zero Day Initiative program, reported a vulnerability in Mozilla's internal CSSValue array data structure. The vulnerability was caused by an insufficiently sized variable being used as a reference counter for CSS objects. By creating a very large number of references to a common CSS object, this counter could be overflowed which could cause a crash when the browser attempts to free the CSS object while still in use. An attacker could use this crash to run arbitrary code on the 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 Bug details embargoed until after the upgrade period * https://bugzilla.mozilla.org/show_bug.cgi?id=440230 * CVE-2008-2785