is_protected_meta in wp-includes/meta.php in WordPress before 5.5.2 allows arbitrary file deletion because it does not properly determine whether a meta key is considered protected.
https://www.debian.org/security/2020/dsa-4784
https://wpscan.com/vulnerability/10452
https://wordpress.org/news/2020/10/wordpress-5-5-2-security-and-maintenance-release/
https://lists.debian.org/debian-lts-announce/2020/11/msg00004.html
https://github.com/WordPress/wordpress-develop/commit/d5ddd6d4be1bc9fd16b7796842e6fb26315705ad