Security researcher Cody Crews discovered a method to append an iframe into an embedded PDF object rendered with the chrome privileged PDF.js. This can used to bypass security restrictions to load local or chrome privileged files and objects within the embedded PDF object. This can lead to information disclosure of local system files.

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/mfsa2013-99.html


Acknowledgements:

Red Hat would like to thank the Mozilla project for reporting this issue. Upstream acknowledges Cody Crews 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