Mozilla » Firefox : Security Vulnerabilities, CVEs, Published In 2015 (CSRF) CVSS score >= 2

The navigator.sendBeacon implementation in Mozilla Firefox before 37.0, Firefox ESR 31.x before 31.6, and Thunderbird before 31.6 processes HTTP 30x status codes for redirects after a preflight request has occurred, which allows remote attackers to bypass intended CORS access-control checks and conduct cross-site request forgery (CSRF) attacks via a crafted web site, a similar issue to CVE-2014-8638.

The navigator.sendBeacon implementation in Mozilla Firefox before 35.0, Firefox ESR 31.x before 31.4, Thunderbird before 31.4, and SeaMonkey before 2.32 omits the CORS Origin header, which allows remote attackers to bypass intended CORS access-control checks and conduct cross-site request forgery (CSRF) attacks via a crafted web site.