Referenced CVEs: 
CVE-2009-0352, CVE-2009-0772, CVE-2009-0774, CVE-2009-0776
Description: 
=========================================================== Ubuntu Security Notice USN-741-1 March 19, 2009 mozilla-thunderbird, thunderbird vulnerabilities CVE-2009-0352, CVE-2009-0772, CVE-2009-0774, CVE-2009-0776 =========================================================== A security issue affects the following Ubuntu releases: Ubuntu 6.06 LTS Ubuntu 7.10 Ubuntu 8.04 LTS Ubuntu 8.10 This advisory also applies to the corresponding versions of Kubuntu, Edubuntu, and Xubuntu. The problem can be corrected by upgrading your system to the following package versions: Ubuntu 6.06 LTS: mozilla-thunderbird 1.5.0.13+1.5.0.15~prepatch080614k-0ubuntu0.6.06.1 Ubuntu 7.10: thunderbird 2.0.0.21+nobinonly-0ubuntu0.7.10.1 Ubuntu 8.04 LTS: thunderbird 2.0.0.21+nobinonly-0ubuntu0.8.04.1 Ubuntu 8.10: thunderbird 2.0.0.21+nobinonly-0ubuntu0.8.10.1 After a standard system upgrade you need to restart Thunderbird to effect the necessary changes. Details follow: Several flaws were discovered in the browser engine. If Javascript were enabled, an attacker could exploit these flaws to crash Thunderbird and possibly execute arbitrary code with user privileges. (CVE-2009-0352) Jesse Ruderman and Gary Kwong discovered flaws in the browser engine. If a user had Javascript enabled, these problems could allow a remote attacker to cause a denial of service or possibly execute arbitrary code with the privileges of the user invoking the program. (CVE-2009-0772, CVE-2009-0774) Georgi Guninski discovered a flaw when Thunderbird performed a cross-domain redirect. If a user had Javascript enabled, an attacker could bypass the same-origin policy in Thunderbird by utilizing nsIRDFService and steal private data from users authenticated to the redirected website. (CVE-2009-0776)