The Mailchimp for WooCommerce WordPress plugin before 2.7.1 has an AJAX action that allows any logged in users (such as subscriber) to perform a POST request on behalf of the server to the internal network/LAN, the body of the request is also appended to the response so it can be used to scan private network for example
https://wpscan.com/vulnerability/e3bd9f8c-919a-40af-9e80-607573e71870