Cis Azure Storage 5.2.7

5.2.7 Ensure 'Cross Subscription Restore' is set to 'Disabled' or 'Permanently Disabled' on Recovery Services vaults (Automated)

Description

Disable cross subscription restore for Recovery Services vaults to ensure that backup data can only be restored within the same subscription as the Recovery Services vault, preventing restoration to targets in other subscriptions.

Rationale

Cross subscription restores increases security risks by widening access to sensitive backup data, potentially leading to accidental or intentional exposure, unauthorized access, or data exfiltration across environments.

Impact

Organizations may need to consider alternatives for disaster recovery scenarios, and if utilizing multiple subscriptions, may need to make adjustments or consider alternatives for data access. Costs could be incurred if alternative or additional backup infrastructure is required to account for the disabling of cross subscription restore.

Audit Procedure

Audit from Azure Portal

1. Go to Recovery Services vaults.
2. Click the name of a Recovery Services vault.
3. Under Settings, click Properties.
4. Under Cross Subscription Restore, click Update.
5. Ensure that Disable Cross Subscription Restore or Permanently disable Cross Subscription Restore on this vault is selected.
6. Repeat steps 1-5 for each Recovery Services vault.

Audit from Azure CLI

Run the following command to list Recovery Services vaults:

az backup vault list

For each Recovery Services vault, run the following command:

az backup vault show --resource-group <resource-group> --name <recovery-services-vault>

Ensure that under properties > restoreSettings > crossSubscriptionRestoreSettings, crossSubscriptionRestoreState is set to Disabled or PermanentlyDisabled.

Audit from PowerShell

Run the following command to list Recovery Services vaults:

Get-AzRecoveryServicesVault

Run the following command to get the Recovery Services vault in a resource group with a given name:

$vault = Get-AzRecoveryServicesVault -ResourceGroupName <resource-group> -Name <recovery-services-vault>

Run the following command to get the cross subscription restore setting for the Recovery Services vault:

$vault.Properties.RestoreSettings.CrossSubscriptionRestoreSettings.CrossSubscriptionRestoreState

Ensure that the command returns Disabled or PermanentlyDisabled. Repeat for each Recovery Services vault.

Audit from Azure Policy

If referencing a digital copy of this Benchmark, clicking a Policy ID will open a link to the associated Policy definition in Azure. If referencing a printed copy, you can search Policy IDs from this URL: https://portal.azure.com/#view/Microsoft_Azure_Policy/PolicyMenuBlade/~/Definitions

• Policy ID: f19b0c83-716f-4b81-85e3-2dbf057c35d6
• Name: '[Preview]: Disable Cross Subscription Restore for Azure Recovery Services vaults'

Expected Result

• properties.restoreSettings.crossSubscriptionRestoreSettings.crossSubscriptionRestoreState is set to Disabled or PermanentlyDisabled
• In Azure Portal, Disable Cross Subscription Restore or Permanently disable Cross Subscription Restore on this vault is selected
• PowerShell returns Disabled or PermanentlyDisabled

Remediation

Remediate from Azure Portal

1. Go to Recovery Services vaults.
2. Click the name of a Recovery Services vault.
3. Under Settings, click Properties.
4. Under Cross Subscription Restore, click Update.
5. Select the radio button next to Disable Cross Subscription Restore or Permanently disable Cross Subscription Restore on this vault.
6. If selecting to permanently disable cross subscription restore, check the box next to Are you sure you want to permanently disable Cross Subscription Restore? Once disabled, it cannot be re-enabled.
7. Click Update.
8. Repeat steps 1-7 for each Recovery Services vault requiring remediation.

Remediate from Azure CLI

For each Recovery Services vault requiring remediation, run the following command to disable cross subscription restore:

az backup vault update --resource-group <resource-group> --name <recovery-services-vault> --cross-subscription-restore-state Disable

Note: Use --cross-subscription-restore-state PermanentlyDisable with the above command to permanently disable cross subscription restore.

Remediate from PowerShell

For each Recovery Services vault requiring remediation, run the following command to disable cross subscription restore:

Update-AzRecoveryServicesVault -ResourceGroupName <resource-group> -Name <recovery-services-vault> -CrossSubscriptionRestoreState Disabled

Note: Use -CrossSubscriptionRestoreState PermanentlyDisabled with the above command to permanently disable cross subscription restore.

Default Value

Cross subscription restore is enabled by default on Recovery Services vaults.

References

1. https://learn.microsoft.com/en-us/cli/azure/backup/vault
2. https://learn.microsoft.com/en-us/powershell/module/az.recoveryservices/get-azrecoveryservicesvault
3. https://learn.microsoft.com/en-us/powershell/module/az.recoveryservices/update-azrecoveryservicesvault
4. https://learn.microsoft.com/en-us/azure/backup/backup-azure-arm-restore-vms#cross-subscription-restore-for-azure-vm

Additional Information

If cross subscription restore is permanently disabled on a vault, it cannot be re-enabled.

CIS Controls

Profile

Level 1 | Automated