Security researcher Cody Crews reported a method to trigger chrome level XML Binding Language (XBL) bindings through web content. This was possible because some chrome accessible CSS stylesheets had their primary namespace improperly declared. When this occurred, it was possible to use these stylesheets to manipulate XBL bindings, allowing web content to bypass security restrictions. This issue was limited to a specific set of stylesheets.



External Reference:

http://www.mozilla.org/security/announce/2014/mfsa2014-84.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, 6 and 7.