Updated thunderbird packages that fix various bugs are now available. This update has been rated as having critical security impact by the Red Hat Security Response Team.
Mozilla Thunderbird is a standalone mail and newsgroup client. A buffer overflow bug was found in the way Thunderbird processes GIF images. It is possible for an attacker to create a specially crafted GIF image, which when viewed by a victim will execute arbitrary code as the victim. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2005-0399 to this issue. A bug was found in the Thunderbird string handling functions. If a malicious website is able to exhaust a system's memory, it becomes possible to execute arbitrary code. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2005-0255 to this issue. Users of Thunderbird are advised to upgrade to this updated package which contains Thunderbird version 1.0.2 and is not vulnerable to these issues.