8.6 Ensure that 'Enable Data Access Authentication Mode' is 'Checked'

Information

Data Access Authentication Mode provides a method of uploading or exporting Virtual Machine Disks.

Rationale:

Enabling data access authentication mode adds a layer of protection using an Entra ID role to further restrict users from creating and using Secure Access Signature (SAS) tokens for exporting a detached managed disk or virtual machine state. Users will need the Data operator for managed disk role within Entra ID in order to download a VHD or VM Guest state using a secure URL.

Impact:

In order to apply this setting, the virtual machine to which the disk or disks are attached will need to be powered down and have their disk detached. Users without the Data operator for managed disk role within Entra ID will not be able to export VHD or VM Guest state using the secure download URL.

Solution

Remediate from Azure Portal
Part A. Select the Virtual Machine to Remediate

Using the search bar, search for and open the Virtual Machines service.

Click on the name of the Virtual Machine to be remediated.

Part B. Remediate each Virtual Machine Disk individually

From the selected Virtual Machine resource window, expand the Settings menu item and click Disks.

For each disk, click the name of the disk to open the disk resource window.

From the selected Disk resource window, expand the Settings menu item, and click Disk Export.

check the checkbox next to Enable Data Access Authentication Mode.
Repeat Part B for each Disk attached to a VM.
Repeat Parts A and B to remediate all Disks in all VMs.

Remediate from PowerShell
Ensure that each disk is detached from its associated Virtual Machine before proceeding. Once detached, run the following for each disk:

$disk = Get-AzDisk -ResourceGroupName '<resource_group_name>' -DiskName '<disk_name>'
$disk.DataAccessAuthMode = 'AzureActiveDirectory'
Update-AzDisk -ResourceGroup '<resource_group_name>' -DiskName $disk.Name -Disk $disk

Remediate from Azure CLI
Ensure that each disk is detached from its associated Virtual Machine before proceeding. Once detached, run the following for each disk:

az disk update --name <disk_name> --resource-group <resource_group_name> --data-access-auth-mode AzureActiveDirectory

Default Value:

By default, Data Access Authentication Mode is Disabled.

See Also

https://workbench.cisecurity.org/benchmarks/16820

Item Details

Category: CONFIGURATION MANAGEMENT, MAINTENANCE

References: 800-53|CM-7, 800-53|MA-4, CSCv7|5.1

Plugin: microsoft_azure

Control ID: 2029fd1a1ab74e71b76218e256810bba5a7feea561e3151951273c6dc58e9b58