firefox is vulnerable to information disclosure. The vulnerability exists as an attacker could create a malicious web page that, when viewed by a victim, could steal private data from a different website the victim has loaded with Firefox.
www.mozilla.org/security/announce/2010/mfsa2010-42.html
www.mozilla.org/security/known-vulnerabilities/firefox36.html#firefox3.6.7
www.redhat.com/security/updates/classification/#critical
access.redhat.com/errata/RHSA-2010:0547
bugzilla.mozilla.org/show_bug.cgi?id=568148
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11835