The Content Security Policy (CSP) functionality in Mozilla Firefox 4.x through 13.0, Firefox ESR 10.x before 10.0.6, Thunderbird 5.0 through 13.0, Thunderbird ESR 10.x before 10.0.6, and SeaMonkey before 2.11 does not properly restrict the strings placed into the blocked-uri parameter of a violation report, which allows remote web servers to capture OpenID credentials and OAuth 2.0 access tokens by triggering a violation.