CIS Microsoft Windows 10 Enterprise Release 1909 Benchmark

18.8.26 Kernel DMA Protection

This section contains recommendations related to Kernel DMA Protection.

This Group Policy section is provided by the Group Policy template DmaGuard.admx/adml that is included with the Microsoft Windows 10 Release 1809 and Server 2019 Administrative Templates (or newer). 18.8.26.1 (BL) Ensure 'Enumeration policy for external devices incompatible with Kernel DMA Protection' is set to 'Enabled: Block All' (Scored)

ProfileApplicability:

 Level 1 (L1) + BitLocker (BL)

 Level 1 (L1) + BitLocker (BL) + Next Generation Windows Security (NG)

 Level 2 (L2) + BitLocker (BL)

 Level 2 (L2) + BitLocker (BL) + Next Generation Windows Security (NG)

 BitLocker (BL) - optional add-on for when BitLocker is deployed

Description:

This policy is intended to provide additional security against external DMA-capable devices. It allows for more control over the enumeration of external DMA-capable devices that are not compatible with DMA Remapping/device memory isolation and sandboxing.

The recommended state for this setting is: Enabled: Block All .

Note : This policy does not apply to 1394, PCMCIA or ExpressCard devices. The protection also only applies to Windows 10 R1803 or higher, and also requires a UEFI BIOS to function.

Note #2 : More information on this feature is available at this link: Kernel DMA Protection for Thunderbolt™ 3 (Windows 10) | Microsoft Docs.

Rationale:

Device memory sandboxing allows the OS to leverage the I/O Memory Management Unit (IOMMU) of a device to block unpermitted I/O, or memory access, by the peripheral.

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