Using the Address Sanitizer tool, security researcher Atte Kettunen from OUSPG found that the HTML5 Tree Builder does not properly store state when interacting with template elements. Because some stack information is incorrectly stored, the template insertion mode stack can be used when it is empty. This could possibly lead to code execution in some circumstances.

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/2013/mfsa2013-77.html


Acknowledgements:

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

Statement:

This issue does not affect the version of firefox and thunderbird as shipped with Red Hat Enterprise Linux 5 and 6