WPC Smart Wishlist for WooCommerce <= 5.0.3 - Insecure Direct Object Reference to Unauthenticated Wishlist Manipulation

The WPC Smart Wishlist for WooCommerce plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.0.3 via several wishlist AJAX functions due to missing validation on a user controlled key that is exposed when wishlists are shared. This makes it possible for unauthenticated attackers to empty and add to other user's wishlists, if they have access to the key.