The WP 2FA – Two-factor authentication for WordPress plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2.5.0. This is due to missing or incorrect nonce validation on the send_backup_codes_email function. This makes it possible for unauthenticated attackers to send emails with arbitrary content to registered users via a forged request granted they can trick a site administrator or other registered user into performing an action such as clicking on a link. While a nonce check is present, it is only executed if a nonce is set. By omitting a nonce from the request, the check can be bypassed.
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
| Name |
Vendor |
Start Version |
End Version |
| Wp_2fa |
Melapress |
* |
2.6.0 (excluding) |
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]
References