The WP Live Chat Support plugin before 8.0.33 for WordPress accepts certain REST API calls without invoking the wplc_api_permission_check protection mechanism.
https://wordpress.org/plugins/wp-live-chat-support/#developers
https://plugins.trac.wordpress.org/log/wp-live-chat-support/
https://plugins.trac.wordpress.org/changeset/2098577/wp-live-chat-support/trunk