CVE-2015-0807

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.

Weakness

The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request.

Affected Software

Potential Mitigations

• Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
• For example, use anti-CSRF packages such as the OWASP CSRFGuard. [REF-330]
• Another example is the ESAPI Session Management control, which includes a component for CSRF. [REF-45]
• Use the “double-submitted cookie” method as described by Felten and Zeller:
• When a user visits a site, the site should generate a pseudorandom value and set it as a cookie on the user’s machine. The site should require every form submission to include this value as a form value and also as a cookie value. When a POST request is sent to the site, the request should only be considered valid if the form value and the cookie value are the same.
• Because of the same-origin policy, an attacker cannot read or modify the value stored in the cookie. To successfully submit a form on behalf of the user, the attacker would have to correctly guess the pseudorandom value. If the pseudorandom value is cryptographically strong, this will be prohibitively difficult.
• This technique requires Javascript, so it may not work for browsers that have Javascript disabled. [REF-331]

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/111.html
• https://cwe.mitre.org/data/definitions/462.html
• https://cwe.mitre.org/data/definitions/467.html
• https://cwe.mitre.org/data/definitions/62.html

References

• http://lists.opensuse.org/opensuse-security-announce/2015-04/msg00003.html
• http://lists.opensuse.org/opensuse-security-announce/2015-04/msg00006.html
• http://lists.opensuse.org/opensuse-security-announce/2015-05/msg00012.html
• http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00031.html
• http://rhn.redhat.com/errata/RHSA-2015-0766.html
• http://rhn.redhat.com/errata/RHSA-2015-0771.html
• http://www.debian.org/security/2015/dsa-3211
• http://www.debian.org/security/2015/dsa-3212
• http://www.mozilla.org/security/announce/2015/mfsa2015-37.html
• http://www.oracle.com/technetwork/topics/security/bulletinapr2015-2511959.html
• http://www.securityfocus.com/bid/73457
• http://www.securitytracker.com/id/1031996
• http://www.securitytracker.com/id/1032000
• http://www.ubuntu.com/usn/USN-2550-1
• http://www.ubuntu.com/usn/USN-2552-1
• https://bugzilla.mozilla.org/show_bug.cgi?id=1111834
• https://security.gentoo.org/glsa/201512-10