Backup Migration <= 1.3.9 - Unauthenticated Path Traversal to Arbitrary File Deletion

The Backup Migration plugin for WordPress is vulnerable to Path Traversal in all versions up to, and including, 1.3.9 via the 'content-backups' and 'content-name', 'content-manifest', or 'content-bmitmp' and 'content-identy' HTTP headers. This makes it possible for unauthenticated attackers to delete arbitrary files, including the wp-config.php file, which can make site takeover and remote code execution possible.