Themeum Tutor LMS – eLearning and online course solution vulnerabilities

The Tutor LMS – eLearning and online course solution plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 4.0.7 via the `withdraw_method_field` parameter of the `tutor_save_withdraw_account` AJAX handler. This is due to the handler lacking any capability or role check, relying solely on a nonce, while also passing attacker-supplied values through `esc_sql()`, which replaces every `%` character with a 66-byte HMAC placeholder token before the data is serialized and stored via `update_user_meta()`; when the meta is later retrieved, the placeholder is collapsed back to a single `%`, leaving serialized string length declarations 65 bytes greater than the actual content, and because array keys originate from entirely unescaped POST field names, `unserialize()` over-reads into attacker-controlled bytes, allowing injection of an arbitrary serialized object stream. This makes it possible for authenticated attackers, with subscriber-level access and above, to achieve remote code execution on the server by triggering the `GuzzleHttp\Cookie\FileCookieJar` POP chain, reachable via the `spl_autoload_register` loader in `TUTOR\RestAPI` which loads the plugin's own bundled PayPal Composer autoloader, writing attacker-controlled content to an attacker-specified filename. This has an unauthenticated pathway when user registration is enabled, which is common for students and teachers to register, and it requires the monetization feature to be enabled.

The Tutor LMS – eLearning and online course solution plugin for WordPress is vulnerable to an Insecure Direct Object Reference in all versions up to, and including, 3.9.7. This is due to missing authentication and authorization checks in the `pay_incomplete_order()` function. The function accepts an attacker-controlled `order_id` parameter and uses it to look up order data, then writes billing fields to the order owner's profile (`$order_data->user_id`) without verifying the requester's identity or ownership. Because the Tutor nonce (`_tutor_nonce`) is exposed on public frontend pages, this makes it possible for unauthenticated attackers to overwrite the billing profile (name, email, phone, address) of any user who has an incomplete manual order, by sending a crafted POST request with a guessed or enumerated `order_id`.

The Tutor LMS – eLearning and online course solution plugin for WordPress is vulnerable to SQL Injection via the 'coupon_code' parameter in all versions up to, and including, 3.9.6 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database. NOTE: This vulnerability was partially mitigated in versions 3.9.4 and 3.9.6.

The Tutor LMS – eLearning and online course solution plugin for WordPress is vulnerable to Insecure Direct Object References (IDOR) in all versions up to, and including, 3.9.5. This is due to missing object-level authorization checks in the `course_list_bulk_action()`, `bulk_delete_course()`, and `update_course_status()` functions. This makes it possible for authenticated attackers, with Tutor Instructor-level access and above, to modify or delete arbitrary courses they do not own by manipulating course IDs in bulk action requests.