The WooCommerce Support Ticket System plugin for WordPress is vulnerable to unauthorized access and loss of data due to missing capability checks on the 'ajax_delete_message', 'ajax_get_customers_partial_list', and 'ajax_get_admins_list' functions in all versions up to, and including, 17.8. This makes it possible for authenticated attackers, with Subscriber-level access and above, to delete arbitrary posts, and read names, emails, and capabilities of all users.