The latest version of Thunderbird can be downloaded from Softpedia
On January 8, Canonical published details about Thunderbird vulnerabilities for its Ubuntu 12.10, Ubuntu 12.04 LTS, Ubuntu 11.10, and Ubuntu 10.04 LTS operating systems in a security notice.According to Canonical, several security issues have been fixed in Thunderbird, which allowed a remote attacker to cause a denial of service via application crash, or potentially execute code with the privileges of the user.
For a more detailed description of the security problems, you can visit Canonical's security notification.
Users can simply fix the security flaws by upgrading the operating systems to the Thunderbird package, specific to each distribution.
A normal system update, executed with the Update Manager, will implement all the necessary changes. A complete system restart is not necessary.
Users can also download Mozilla Thunderbird 17.0.2 right now from Softpedia.