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(TM) 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. 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.
To establish the recommended configuration, set the following Device Configuration Policy to Enabled: Block All: To access the Device Configuration Policy from the Intune Home page: Click Devices Click Configuration profiles Click Create profile Select the platform (Windows 10 and later) Select the profile (Custom) Click Create Enter a Name Click Next Configure the following Setting Name: <Enter name> Description: <Enter Description> OMA-URL: ./Device/Vendor/MSFT/Policy/Config/DmaGuard/DeviceEnumerationPolicy Data Type: Integer Value: 0 Select OK Continue through the Wizard to complete the creation of the profile (profile assignments, applicability etc.) Note: More than one configuration setting from each of the Configuration profiles (ex: Administrative Templates, Custom etc.) can be added to each Device Configuration Policy. Note 2: This recommendation can also be set using the Endpoint protection profile using Windows Encryption settings. Default Value: Windows 10 R1803 and newer: Enabled if UEFI BIOS is present. Disabled if using legacy BIOS. Older OSes: Not supported (i.e. Disabled).