The YITH WooCommerce Waitlist Premium plugin for WordPress is vulnerable to Privilege Escalation in versions up to, and including, 3.35.0. This is due to the add_user_in_waiting_list() function registered on the wp_ajax_yith_wcwtl_add_user action being missing both a capability check and a nonce verification, and using parse_str() + extract() to import attacker-controlled variables from $_POST['params'] that are then passed to wp_create_user() and $user->set_role(). This makes it possible for authenticated attackers, with Subscriber-level access and above, to elevate their privileges to that of an administrator by creating a new user account and assigning it the administrator role.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1