Security researcher Fabián Cuchietti discovered that it was possible to bypass the restriction on JavaScript execution in mail by embedding an <iframe> with a data: URL within a message. If the victim replied or forwarded the mail after receiving it, quoting it "in-line" using Thunderbird's HTML mail editor, it would run the attached script. The running script would be restricted to the mail composition window where it could observe and potentially modify the content of the mail before it was sent. Scripts were not executed if the recipient merely viewed the mail, only if it was edited as HTML. Turning off HTML composition prevented the vulnerability and forwarding the mail "as attachment" prevented the forwarding variant. Ateeq ur Rehman Khan of Vulnerability Labs reported additional variants of this attack involving the use of the <object> tag and which could be used to attach object data types such as images, audio, or video. External Reference: http://www.mozilla.org/security/announce/2014/mfsa2014-14.html Acknowledgements: Red Hat would like to thank the Mozilla project for reporting this issue. Upstream acknowledges Fabián Cuchietti and Ateeq ur Rehman Khan as the original reporter.
Upstream notes the following: This affected the Thunderbird 17 branch. It was fixed in all versions based on Gecko 23 or later. Thunderbird 24 and later are not affected by this vulnerability.
Statement: This issue was resolved in the version of thunderbird as shipped with Red Hat Enterprise Linux 5 and 6 via RHSA-2013:1823.
Common Vulnerabilities and Exposures assigned an identifier CVE-2014-2018 to the following vulnerability: Name: CVE-2014-2018 URL: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-2018 Reference: MISC: http://www.vulnerability-lab.com/get_content.php?id=953 Reference: CONFIRM: http://www.mozilla.org/security/announce/2014/mfsa2014-14.html Reference: CONFIRM: https://bugzilla.mozilla.org/show_bug.cgi?id=875818 Reference: CERT-VN:VU#863369 Reference: URL: http://www.kb.cert.org/vuls/id/863369 Cross-site scripting (XSS) vulnerability in Mozilla Thunderbird 17.x through 17.0.8, Thunderbird ESR 17.x through 17.0.10, and SeaMonkey before 2.20 allows user-assisted remote attackers to inject arbitrary web script or HTML via an e-mail message containing a data: URL in a (1) OBJECT or (2) EMBED element, a related issue to CVE-2013-6674.