“Although the vulnerability was fixed in Microsoft’s January 2022 update, its exploitation is still possible as the affected, validly signed binaries have still not been added to the UEFI revocation list.”
BlackLotus sells on hacking forums for $5,000 and beats Secure Boot on fully patched Windows 11. Microsoft fixed the bug more than a year ago. The attacker simply brings along the old, validly signed bootloaders that Microsoft never revoked. It also switches off BitLocker, HVCI and Defender. Secure Boot only works if someone maintains the blocklist, and nobody did.