IP2Location Country Blocker < 2.26.5 - Subscriber+ Arbitrary Country Ban

The IP2Location Country Blocker WordPress plugin before 2.26.5 does not have authorisation and CSRF checks in the ip2location_country_blocker_save_rules AJAX action, allowing any authenticated users, such as subscriber to call it and block arbitrary country, or block all of them at once, preventing users from accessing the frontend.