CWE-352

The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.

Common consequences

• Confidentiality, Integrity, Availability, Non-Repudiation, Access Control → Gain Privileges or Assume Identity, Bypass Protection Mechanism, Read Application Data, Modify Application Data, DoS: Crash, Exit, or Restart

Mitigations

• Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482]. 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]
• Implementation: Ensure that the application is free of cross-site scripting issues (CWE-79), because most CSRF defenses can be bypassed using attacker-controlled script.
• Architecture and Design: Generate a unique nonce for each form, place the nonce into the form, and verify the nonce upon receipt of the form. Be sure that the nonce is not predictable (CWE-330). [REF-332]
• Architecture and Design: Identify especially dangerous operations. When the user performs a dangerous operation, send a separate confirmation request to ensure that the user intended to perform that operation.
• Architecture and Design: 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
• Architecture and Design: Do not use the GET method for any request that triggers a state change.