Events Calendar for GeoDirectory <= 2.3.28 - Authenticated (Subscriber+) Privilege Escalation

The Events Calendar for GeoDirectory plugin for WordPress is vulnerable to Privilege Escalation in versions up to and including 2.3.28. This is due to the ajax_ayi_action() handler only applying strip_tags(esc_sql()) — with no allow-list — to the attacker-controlled $_POST['type'] and $_POST['postid'] values before forwarding them to update_ayi_data(), which calls update_user_meta($current_user->ID, $rsvp_args['type'], $posts). By passing type=wp_capabilities and postid=administrator, an attacker writes ['subscriber'=>true,'administrator'=>'administrator'] into their own wp_capabilities user meta; WP_User::get_role_caps() then treats the 'administrator' array key as an active role on the next request. This makes it possible for authenticated attackers, with Subscriber-level access and above, to elevate their privileges to Administrator.