CVE 2011-2990

The implementation of Content Security Policy (CSP) violation reports in Mozilla Firefox 4.x through 5, SeaMonkey 2.x before 2.3, and possibly other products does not remove proxy-authorization credentials from the listed request headers, which allows attackers to obtain sensitive information by reading a report, related to incorrect host resolution that occurs with certain redirects.

See the CVE page on Mitre.org for more details.