Mozilla Developer Bobby Holley and Mozilla security researcher moz_bug_r_a4 discovered a mechanism where XBL scopes can be be used to circumvent XrayWrappers from within the Chrome on unprivileged objects. This allows web content to potentially confuse privileged code and weaken invariants and can lead to cross-site scripting (XSS) attacks. In general these flaws cannot be exploited through email in the Thunderbird and SeaMonkey products because scripting is disabled, but are potentially a risk in browser or browser-like contexts in those products. External Reference: http://www.mozilla.org/security/announce/2013/mfsa2013-70.html Acknowledgements: Red Hat would like to thank the Mozilla project for reporting this issue. Upstream acknowledges Bobby Holley and moz_bug_r_a4 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