diff --git a/windows/keep-secure/credential-guard-requirements.md b/windows/keep-secure/credential-guard-requirements.md index ee45ea20a9..59e3915359 100644 --- a/windows/keep-secure/credential-guard-requirements.md +++ b/windows/keep-secure/credential-guard-requirements.md @@ -117,8 +117,6 @@ The following table lists qualifications for Windows 10, version 1703, which are | Firmware: **VBS enablement of NX protection for UEFI runtime services** | **Requirements**:
• VBS will enable No-Execute (NX) protection on UEFI runtime service code and data memory regions. UEFI runtime service code must support read-only page protections, and UEFI runtime service data must not be executable.
• UEFI runtime service must meet these requirements:
    - Implement UEFI 2.6 EFI_MEMORY_ATTRIBUTES_TABLE. All UEFI runtime service memory (code and data) must be described by this table.
    - PE sections need to be page-aligned in memory (not required for in non-volatile storage).
    - The Memory Attributes Table needs to correctly mark code and data as RO/NX for configuration by the OS:
        - All entries must include attributes EFI_MEMORY_RO, EFI_MEMORY_XP, or both
        - No entries may be left with neither of the above attributes, indicating memory that is both executable and writable. Memory must be either readable and executable or writeable and non-executable.

Notes:
• This only applies to UEFI runtime service memory, and not UEFI boot service memory.
• This protection is applied by VBS on OS page tables.


Please also note the following:
• Do not use sections that are both writeable and executable
• Do not attempt to directly modify executable system memory
• Do not use dynamic code

**Security benefits**:
• Vulnerabilities in UEFI runtime, if any, will be blocked from compromising VBS (such as in functions like UpdateCapsule and SetVariable)
• Reduces the attack surface to VBS from system firmware. | | Firmware: **Firmware support for SMM protection** | **Requirements**: The [Windows SMM Security Mitigations Table (WSMT) specification](http://download.microsoft.com/download/1/8/A/18A21244-EB67-4538-BAA2-1A54E0E490B6/WSMT.docx) contains details of an Advanced Configuration and Power Interface (ACPI) table that was created for use with Windows operating systems that support Windows virtualization-based security (VBS) features.

**Security benefits**:
• Protects against potential vulnerabilities in UEFI runtime services, if any, will be blocked from compromising VBS (such as in functions like UpdateCapsule and SetVariable)
• Reduces the attack surface to VBS from system firmware.
• Blocks additional security attacks against SMM. | -
- ## See also Microsoft has created a new **Deep Dive into Credential Guard** video series that explores the main features of Credential Guard and how it works.