Security researcher Nils used the Address Sanitizer tool while fuzzing to discover a memory corruption issue with the JavaScript engine when using workers with direct proxies. This results in a potentially exploitable crash.

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


External Reference:

http://www.mozilla.org/security/announce/2013/mfsa2013-101.html


Acknowledgements:

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