The UpdraftPlus: WordPress Backup & Migration Plugin plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 1.23.10. This is due to a lack of nonce validation and insufficient validation of the instance_id on the 'updraftmethod-googledrive-auth' action used to update Google Drive remote storage location. This makes it possible for unauthenticated attackers to modify the Google Drive location that backups are sent to via a forged request granted they can trick a site administrator into performing an action such as clicking on a link. This can make it possible for attackers to receive backups for a site which may contain sensitive information.
The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.