BackWPup < 5.7.7 - Unauthenticated Sensitive Data Disclosure via Restore Working Directory on NGINX

Description

The plugin does not properly restrict web access to the working directory it uses during backup restores, allowing unauthenticated attackers, on webservers that do not honour .htaccess rules such as NGINX, to download the full backup archive (database dump and site files, including credentials and secret keys) left behind by an interrupted restore.