Jonathan Watt

**Name of the Vulnerable Software and Affected Versions** Mozilla Firefox versions 4.x through 5 Thunderbird versions prior to 6 SeaMonkey versions 2.x prior to 2.3 **Description** The issue affects the browser engine, allowing remote attackers to cause a denial of service, which results in memory corruption and application crash, or possibly execute arbitrary code. The exact vectors used for the attack are unknown. **Recommendations** For Mozilla Firefox versions 4.x through 5, update to a version later than 5 to resolve the issue. For Thunderbird versions prior to 6, update to version 6 or later to resolve the issue. For SeaMonkey versions 2.x prior to 2.3, update to version 2.3 or later to resolve the issue.