The 1 Click WordPress Migration Plugin – 100% FREE for a limited time plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 2.1 via the class-ocm-backup.php. This makes it possible for unauthenticated attackers to extract sensitive data including usernames and their respective password hashes during a short window of time in which the backup is in process.
https://plugins.trac.wordpress.org/browser/1-click-migration/trunk/inc/backup/class-ocm-backup.php