Yes, because of Microsoft's key signing program, UEFI security is already fatally flawed even without this new issue. See for example https://habr.com/en/post/4

Yes, because of Microsoft's key signing program, UEFI security is already fatally flawed even without this new issue. See for example https://habr.com/en/post/446238/ https://habr.com/en/post/446238/ > In this article we proved the existence of not enough reliable bootloaders signed by Microsoft key, which allows booting untrusted code in Secure Boot mode. Using signed Kaspersky Rescue Disk files, we achieved a silent boot of any untrusted .efi files with Secure Boot enabled, without the need to add a certificate to UEFI db or shim MOK.