This attack could pose a moderate security threat. It does not require immediate action.
Mozilla Firefox, SeaMonkey, and Thunderbird are prone to a remote code-execution vulnerability; fixes are available.
Firefox is a browser. SeaMonkey is a suite of applications that includes a browser and an email client. Thunderbird is an email client. All three applications are available for multiple platforms.
An attacker can exploit this issue to execute arbitrary code in the context of the affected application. Failed exploit attempts will likely result in denial-of-service conditions.
NOTE: This issue was previously discussed in BID 48354 (Mozilla Firefox/Thunderbird/SeaMonkey MFSA 2011-19 through -28 Multiple Vulnerabilities) but has been given its own record to better document it.
Updates are available. Please see the references for more information.