BackWPup – WordPress Backup & Restore Plugin

The BackWPup plugin for WordPress is vulnerable to Local File Inclusion via the `block_name` parameter of the `/wp-json/backwpup/v1/getblock` REST endpoint in all versions up to, and including, 5.6.6 due to a non-recursive `str_replace()` sanitization of path traversal sequences. This makes it possible for authenticated attackers, with Administrator-level access and above, to include arbitrary PHP files on the server via crafted traversal sequences (e.g., `....//`), which can be leveraged to read sensitive files such as `wp-config.php` or achieve remote code execution in certain configurations. Administrators have the ability to grant individual users permission to handle backups, which may then allow lower-level users to exploit this vulnerability.

The BackWPup – WordPress Backup & Restore Plugin plugin for WordPress is vulnerable to unauthorized modification of data that can lead to privilege escalation due to a missing capability check on the save_site_option() function in all versions 5.0.0 to 5.6.2. This makes it possible for authenticated attackers, with level access and above, to update arbitrary options on the WordPress site. This can be leveraged to update the default role for registration to administrator and enable user registration for attackers to gain administrative user access to a vulnerable site.

The BackWPup – WordPress Backup & Restore Plugin plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the 'backwpup_working' AJAX action in versions 5 through 5.5.0. This makes it possible for authenticated attackers, with Subscriber-level access and above, to retrieve access to a back-up's filename while a backup is running. This information has little value on it's own, but could be used to aid in a brute force attack to retrieve back-up contents in limited environments (i.e. NGINX).