The BackupSheep WordPress Backup Plugin WordPress plugin through 1.8 does not properly validate its integration key, treating an unset or blank key as valid, which allows unauthenticated attackers to create and download full site backups, including the database with user password hashes, and to delete arbitrary files on the server, leading to sensitive data disclosure and site takeover.
The BackupSheep WordPress Backup Plugin WordPress plugin through 1.8 has been closed on WordPress.org since July 2024 and no fixed version is available. Remove it from any site where it is installed.