CVE-2021-4339

The uListing plugin for WordPress is vulnerable to authorization bypass due to a missing capability check in the "ulisting/includes/route.php" file on the /1/api/ulisting-user/search REST-API route in versions up to, and including, 1.6.6. This makes it possible for unauthenticated attackers to retrieve the list of all users and their email address in the database.

Source: CVE-2021-4339