In Firefox, it is possible to make requests using IPv6 syntax (http://[example.com]/) via XMLHttpRequest objects. If an HTTP proxy has been configured, the request will be handled by the proxy. Depending on proxy implementations some errors may occur. Error messages from HTTP proxies often include sensitive network diagnostic information such as client IP addresses, internal hostnames, email addresses and possibly a copy of the HTTP request. Because http://example.com/ and http://[example.com]/ are same origin, the XMLHttpRequest object can be used to read this information from the response. A remote site may be able to construct such requests in order to reduce a user's privacy. Additionally, if a copy of the HTTP request is included in the error response, it may be possible to read cookies marked as HttpOnly in XSS situations. Reference: https://bugzilla.mozilla.org/show_bug.cgi?id=504014
Public now via: http://www.mozilla.org/security/announce/2012/mfsa2012-02.html
External References: http://www.mozilla.org/security/announce/2012/mfsa2012-02.html
This issue has been addressed in following products: Red Hat Enterprise Linux 6 Via RHSA-2012:0080 https://rhn.redhat.com/errata/RHSA-2012-0080.html
This issue has been addressed in following products: Red Hat Enterprise Linux 4 Red Hat Enterprise Linux 5 Red Hat Enterprise Linux 6 Via RHSA-2012:0079 https://rhn.redhat.com/errata/RHSA-2012-0079.html
This issue has been addressed in following products: Red Hat Enterprise Linux 4 Red Hat Enterprise Linux 5 Via RHSA-2012:0085 https://rhn.redhat.com/errata/RHSA-2012-0085.html
This issue has been addressed in following products: Red Hat Enterprise Linux 4 Via RHSA-2012:0084 https://rhn.redhat.com/errata/RHSA-2012-0084.html