The WPO365 | Login plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 43.2. This is due to the Ajax_Service::verify_ajax_request() helper gating its wp_verify_nonce() call behind the boolean option enable_nonce_check, which is absent from the default wpo365_options array and therefore evaluates to false via get_global_boolean_var(); as a result, the wp_ajax_wpo365_update_settings handler (Ajax_Service::update_settings) accepts POSTs from cross-origin pages and forwards the attacker-supplied settings payload (base64/JSON) to Options_Service::update_options(), which merges every key/value into wpo365_options without a key allowlist. This makes it possible for unauthenticated attackers to overwrite arbitrary plugin options — including enabling the SCIM REST endpoint (enable_scim), planting an attacker-known scim_secret_token, and setting new_usr_default_role to administrator — via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
Weakness
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.
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 [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]
- 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