Mozilla Thunderbird is a standalone mail and newsgroup client.
Several flaws were found in the way in which Thunderbird displayed malformed HTML mail content. An HTML mail message containing specially-crafted content could potentially trick a user into surrendering sensitive information. (CVE-2007-1095, CVE-2007-3844, CVE-2007-3511, CVE-2007-5334)
A flaw was found in the Thunderbird sftp protocol handler. A malicious HTML mail message could access data from a remote sftp site, possibly stealing sensitive user data. (CVE-2007-5337)
A request-splitting flaw was found in the way in which Thunderbird generates a digest authentication request. If a user opened a specially-crafted URL, it was possible to perform cross-site scripting attacks, web cache poisoning, or other, similar exploits. (CVE-2007-2292)
Users of Thunderbird are advised to upgrade to these erratum packages, which contain backported patches that correct these issues.