Security researcher Masato Kinugawa reported a cross-origin information leak through web workers' error messages. This violates same-origin policy and the leaked information could potentially be used to gather authentication tokens and other data from third-party websites.

In general this flaw cannot be exploited through email in the Thunderbird and Seamonkey products because scripting is disabled in mail, but is potentially a risk in browser or browser-like contexts.


External Reference:

http://www.mozilla.org/security/announce/2014/mfsa2014-09.html


Acknowledgements:

Red Hat would like to thank the Mozilla project for reporting this issue. Upstream acknowledges Masato Kinugawa as the original reporter.