WP Remote Users Sync <= 1.2.12 is vulnerable to Authenticated (Subscriber+) Server Side Request Forgery vulnerability

The WP Remote Users Sync plugin for WordPress is vulnerable to Server Side Request Forgery via the 'notify_ping_remote' AJAX function in versions up to, and including, 1.2.12. This can allow authenticated attackers with subscriber-level permissions or above to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services. This was partially patched in version 1.2.12 and fully patched in version 1.2.13.