Mozilla Thunderbird is a standalone mail and newsgroup client. Several flaws were found in the processing of malformed content. Malicious content could cause Thunderbird to crash or, potentially, execute arbitrary code with the privileges of the user running Thunderbird. A buffer overflow flaw was found in the way Thunderbird handled GIF images. Content containing a malicious GIF image could cause Thunderbird to crash or, possibly, execute arbitrary code with the privileges of the user running Thunderbird. A flaw was found in the way Thunderbird decoded the HZ-GB-2312 character encoding. Malicious content could cause Thunderbird to run JavaScript code with the permissions of different content. A flaw was found in the location object implementation in Thunderbird. Malicious content could possibly use this flaw to allow restricted content to be loaded by plug-ins. A flaw was found in the way cross-origin wrappers were implemented. Malicious content could use this flaw to perform cross-site scripting attacks. A flaw was found in the evalInSandbox implementation in Thunderbird. Malicious content could use this flaw to perform cross-site scripting attacks. Red Hat would like to thank the Mozilla project for reporting these issues. Upstream acknowledges Abhishek Arya, miaubiz, Jesse Ruderman, Andrew McCreight, Bob Clary, Kyle Huey, Atte Kettunen, Masato Kinugawa, Mariusz Mlynski, Bobby Holley, and moz_bug_r_a4 as the original reporters of these issues. Note: All issues except CVE-2012-4202 cannot be exploited by a specially-crafted HTML mail message as JavaScript is disabled by default for mail messages. They could be exploited another way in Thunderbird, for example, when viewing the full remote content of an RSS feed. All Thunderbird users should upgrade to this updated package, which contains Thunderbird version 10.0.11 ESR, which corrects these issues. After installing the update, Thunderbird must be restarted for the changes to take effect.