Security researcher Muneaki Nishimura discovered that Content Security Policy (CSP) violation reports triggered by a redirect did not remove path information as required by the CSP specification. This potentially reveals information about the redirect that would not otherwise be known to the original site. This could be used by a malicious site to obtain sensitive information such as usernames or single-sign-on tokens encoded within the target URLs. 

External Reference:

http://www.mozilla.org/security/announce/2014/mfsa2014-86.html


Acknowledgements:

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