Detections
Analytics

18.9.24.1 Ensure 'Enumeration policy for external devices incompatible with Kernel DMA Protection' is set to 'Enabled: Block All'

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This audit has been deprecated and will be removed in a future update.

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Information

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 requires a UEFI BIOS to function.

Note #2 : More information on this feature is available at this link: Kernel DMA Protection for Thunderbolt(TM) 3 (Windows 10) | Microsoft Docs https://docs.microsoft.com/en-us/windows/security/information-protection/kernel-dma-protection-for-thunderbolt.

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.

Solution

To establish the recommended configuration via GP, set the following UI path to Enabled: Block All :

Computer Configuration\Policies\Administrative Templates\System\Kernel DMA Protection\Enumeration policy for external devices incompatible with Kernel DMA Protection

Note: This Group Policy path is provided by the Group Policy template DmaGuard.admx/adml that is included with the Microsoft Windows 10 Release 1809 & Server 2019 Administrative Templates (or newer).

Impact:

External devices that are not compatible with DMA-remapping will not be enumerated and will not function unless/until the user has logged in successfully and has an unlocked user session. Once enumerated, these devices will continue to function, regardless of the state of the session. Devices that are compatible with DMA-remapping will be enumerated immediately, with their device memory isolated.

See Also

https://workbench.cisecurity.org/benchmarks/25561

Item Details

References: CSCv7|1.4

Plugin: Windows

Control ID: def9e2b226523887ba56ce340cff2aed6aafc2c966628bc8cc02f479aa79c791