Security researcher regenrecht reported, via TippingPoint's Zero Day Initiative, a use-after-free during text layout when interacting with the setting of text direction. This results in a use-after-free which can lead to arbitrary code execution.

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


External Reference:

http://www.mozilla.org/security/announce/2014/mfsa2014-72.html


Acknowledgements:

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