Vulnerability Discussion

UEFI provides additional security features in comparison to legacy BIOS firmware, including Secure Boot. UEFI is required to support additional security features in Windows Server 2016, including Virtualization Based Security and Credential Guard. Systems with UEFI that are operating in "Legacy BIOS" mode will not support these security features.

Check

Some older systems may not have UEFI firmware. This is currently a CAT III; it will be raised in severity at a future date when broad support of Windows hardware and firmware requirements are expected to be met. Devices that have UEFI firmware must run in "UEFI" mode.

Verify the system firmware is configured to run in "UEFI" mode, not "Legacy BIOS".

Run "System Information".

Under "System Summary", if "BIOS Mode" does not display "UEFI", this is a finding.

Fix

Configure UEFI firmware to run in "UEFI" mode, not "Legacy BIOS" mode.