The YITH WooCommerce Wishlist plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 4.10.0. This is due to the plugin not properly verifying that a user is authorized to perform actions on the REST API /wp-json/yith/wishlist/v1/lists endpoint (which uses permission_callback => __return_true) and the AJAX delete_item handler (which only checks nonce validity without verifying object-level authorization). This makes it possible for unauthenticated attackers to disclose wishlist tokens for any user and subsequently delete wishlist items by chaining the REST API authorization bypass with the exposed delete_item nonce on shared wishlist pages and the AJAX handlers missing object-level authorization check.
The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
Assuming a user with a given identity, authorization is the process of determining whether that user can access a given resource, based on the user’s privileges and any permissions or other access-control specifications that apply to the resource. When access control checks are not applied consistently - or not at all - users are able to access data or perform actions that they should not be allowed to perform. This can lead to a wide range of problems, including information exposures, denial of service, and arbitrary code execution.