Security researcher Masato Kinugawa found a flaw in which the displayed URL values within the addressbar can be spoofed by a page during loading. This allows for phishing attacks where a malicious page can spoof the identify of another site.

In general, browsing focused flaws cannot be exploited through email in the Thunderbird and SeaMonkey except in browser or browser-like contexts in those products where scripting is enabled.


External Reference:

http://www.mozilla.org/security/announce/2013/mfsa2013-04.html


Acknowledgements:

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