Conditional Access: Filter for devices

When administrators create Conditional Access policies, the ability to target or exclude specific devices in their environment is a common task. The condition filter for devices gives administrators the ability to target specific devices. Administrators can use supported operators and properties for device filters along side the other available assignment conditions in your Conditional Access policies.

Common scenarios

There are multiple scenarios that organizations can now enable using filter for devices condition. The following scenarios provide examples of how to use this new condition.

• Restrict access to privileged resources. For this example, lets say you want to allow access to Azure Service Management API from a user who:
  • Is assigned a privileged role.
  • Completed multifactor authentication.
  • Is on a device that is privileged or secure admin workstations and attested as compliant.
  • For this scenario, organizations would create two Conditional Access policies:
    • Policy 1: All users with an administrator role, accessing the Azure Service Management API cloud app, and for Access controls, Grant access, but require multifactor authentication and require device to be marked as compliant.
    • Policy 2: All users with an administrator, accessing the Azure Service Management API cloud app, excluding a filter for devices using rule expression device.extensionAttribute1 equals SAW and for Access controls, Block. Learn how to update extensionAttributes on a Microsoft Entra device object.
• Block access to organization resources from devices running an unsupported Operating System. For this example, lets say you want to block access to resources from Windows OS version older than Windows 10. For this scenario, organizations would create the following Conditional Access policy:
  • All users, accessing all resources, excluding a filter for devices using rule expression device.operatingSystem equals Windows and device.operatingSystemVersion startsWith "10.0" and for Access controls, Block.
• Do not require multifactor authentication for specific accounts on specific devices. For this example, lets say you want to not require multifactor authentication when using service accounts on specific devices like Teams Phones or Surface Hub devices. For this scenario, organizations would create the following two Conditional Access policies:
  • Policy 1: All users excluding service accounts, accessing all resources, and for Access controls, Grant access, but require multifactor authentication.
  • Policy 2: Select users and groups and include group that contains service accounts only, accessing all resources, excluding a filter for devices using rule expression device.extensionAttribute2 not equals TeamsPhoneDevice and for Access controls, Block.

Create a Conditional Access policy

Filter for devices is an optional control when creating a Conditional Access policy.

The following steps help create two Conditional Access policies to support the first scenario under Common scenarios.

Policy 1: All users with an administrator role, accessing the Azure Service Management API cloud app, and for Access controls, Grant access, but require multifactor authentication and require device to be marked as compliant.

1. Sign in to the Azure portal as at least a Conditional Access Administrator.
2. Browse to Microsoft Entra ID > security> Conditional Access
3. Select Create new policy.
4. Give your policy a name. We recommend that organizations create a meaningful standard for the names of their policies.
5. Under Assignments, select Users or workload identities.

   1. Under Include, select Directory roles, then all roles with administrator in the name.

      Warning

      Conditional Access policies support built-in roles. Conditional Access policies are not enforced for other role types including administrative unit-scoped or custom roles.

   2. Under Exclude, select Users and groups and choose your organization's emergency access or break-glass accounts.

   3. Select Done.

6. Under Target resources > Resources (formerly cloud apps) > Include > Select resources, choose Azure Service Management API, and select Select.
7. Under Access controls > Grant, select Grant access, Require multifactor authentication, and Require device to be marked as compliant, then select Select.
8. Confirm your settings and set Enable policy to On.
9. Select Create to create to enable your policy.

Policy 2: All users with an administrator role, accessing the Azure Service Management API cloud app, excluding a filter for devices using rule expression device.extensionAttribute1 equals SAW and for Access controls, Block.

1. Select New policy.
2. Give your policy a name. We recommend that organizations create a meaningful standard for the names of their policies.
3. Under Assignments, select Users or workload identities.

   1. Under Include, select Directory roles, then all roles with administrator in the name

      Warning

      Conditional Access policies support built-in roles. Conditional Access policies are not enforced for other role types including administrative unit-scoped or custom roles.

   2. Under Exclude, select Users and groups and choose your organization's emergency access or break-glass accounts.

   3. Select Done.

4. Under Target resources > Resources (formerly cloud apps) > Include > Select resources, choose Azure Service Management API, and select Select.
5. Under Conditions, Filter for devices.
   1. Toggle Configure to Yes.
   2. Set Devices matching the rule to Exclude filtered devices from policy.
   3. Set the property to ExtensionAttribute1, the operator to Equals and the value to SAW.
   4. Select Done.
6. Under Access controls > Grant, select Block access, then select Select.
7. Confirm your settings and set Enable policy to On.
8. Select Create to create to enable your policy.

Setting attribute values

Setting extension attributes is made possible through the Microsoft Graph API. For more information about setting device attributes, see the article Update device.

Filter for devices Graph API

The filter for devices API is available in Microsoft Graph v1.0 endpoint and can be accessed using the endpoint https://microsoftgraph.chinacloudapi.cn/v1.0/identity/conditionalaccess/policies/. You can configure a filter for devices when creating a new Conditional Access policy or you can update an existing policy to configure the filter for devices condition. To update an existing policy, you can do a patch call on the Microsoft Graph v1.0 endpoint by appending the policy ID of an existing policy and executing the following request body. The example here shows configuring a filter for devices condition excluding devices that aren't marked as SAW devices. The rule syntax can consist of more than one single expression. To learn more about the syntax, see rules for dynamic membership groups for groups in Microsoft Entra ID.

{
    "conditions": {
        "devices": {
            "deviceFilter": {
                "mode": "exclude",
                "rule": "device.extensionAttribute1 -ne \"SAW\""
            }
        }
    }
}

Supported operators and device properties for filters

The following device attributes can be used with the filter for devices condition in Conditional Access.

Policy behavior with filter for devices

The filter for devices condition in Conditional Access evaluates policy based on device attributes of a registered device in Microsoft Entra ID and hence it's important to understand under what circumstances the policy is applied or not applied. The following table illustrates the behavior when a filter for devices condition is configured.

Related content

• Back to school - Using Boolean algebra correctly in complex filters
• Update device Graph API
• Conditional Access: Conditions
• Common Conditional Access policies