Azure Cloud Blog

Alex Johnson

Published on October 26, 2023

Azure AD Conditional Access: Mastering Advanced Scenarios

Azure Active Directory (Azure AD) Conditional Access is a powerful tool for enforcing granular access control to your cloud applications. While basic policies are straightforward, mastering advanced scenarios can significantly enhance your organization's security posture, streamline user access, and improve compliance.

Scenario 1: Device Compliance for Critical Apps

Ensuring that only compliant and managed devices can access your most sensitive applications is a cornerstone of modern security. Conditional Access makes this achievable.

Objective: Allow access to applications like SAP or Workday only from Azure AD joined or Hybrid Azure AD joined devices that are marked as compliant by Microsoft Intune.

Configuration Steps:

1. Define a Named Location for trusted IP ranges (e.g., your corporate network).
2. Create a Client apps target for the cloud apps you want to protect (e.g., SAP, Workday).
3. Under Conditions, configure the following:
   • Device Platforms: Select all platforms.
   • Device State: Choose Required and select Hybrid Azure AD joined devices and Azure AD joined devices.
   • Filter for devices (Preview): Configure a filter to target specific device compliance states (e.g., device.complianceState -eq "Compliant").
4. Under Access controls:
   • Grant: Select Grant access and require Require device to be marked as compliant.

This policy will ensure that users attempting to access these critical applications must do so from a corporate-managed and compliant device. If the device is not compliant, access will be blocked.

Scenario 2: Per-User MFA for Risky Sign-ins

Azure AD Identity Protection offers risk detection for users and sign-ins. You can combine this with Conditional Access to enforce Multi-Factor Authentication (MFA) dynamically based on the perceived risk.

Objective: Require MFA for all users when a sign-in is detected as risky.

Configuration Steps:

1. Under Users, target All users.
2. Under Target resources, select Cloud apps and choose All cloud apps.
3. Under Conditions, select Sign-in risk and choose Medium and above.
4. Under Access controls:
   • Grant: Select Grant access and require Multi-Factor Authentication.

Additionally, you can create a separate policy to require MFA for User risk: High for any sign-in, regardless of the sign-in risk. This layered approach provides robust protection against account compromise.

Scenario 3: Session Controls for Data Protection

Session controls in Conditional Access allow you to limit how users interact with cloud apps, even after successful authentication. This is crucial for preventing data leakage.

Objective: Prevent users from downloading sensitive data from SharePoint Online when accessing from untrusted locations.

Configuration Steps:

1. Under Users, target specific groups or all users.
2. Under Target resources, select Cloud apps and choose Office 365 SharePoint Online.
3. Under Conditions, select Locations and configure it to target Any location, but Exclude your trusted IP locations.
4. Under Access controls:
   • Session: Select Use Conditional Access App Control. Choose Block download for SharePoint Online.

With this policy, users accessing SharePoint Online from outside your corporate network will be allowed to view documents but will be prevented from downloading them, thereby protecting sensitive data.

Scenario 4: Custom Controls and Third-Party Integrations

Azure AD Conditional Access isn't limited to Microsoft's own services. It can integrate with third-party Identity Providers (IdPs) and security solutions to enforce custom access policies.

Objective: Integrate with a Data Loss Prevention (DLP) solution to block access to specific sensitive apps if DLP detects a policy violation.

This scenario typically involves configuring a custom control within Conditional Access that leverages an external service. The exact steps depend heavily on the third-party solution, but the general flow is:

1. The third-party solution is registered as an application within Azure AD.
2. Conditional Access policies are configured to call this custom control.
3. When a user attempts to access a protected resource, Conditional Access checks with the third-party service via an API.
4. The third-party service evaluates its own policies (e.g., DLP scans) and returns an allow or deny decision.
5. Conditional Access enforces the decision.

This allows for highly specialized security requirements, such as enforcing access based on data sensitivity labels or user behavior analytics from a non-Microsoft security product.

Conclusion

Azure AD Conditional Access is a dynamic and flexible policy engine that can adapt to a wide range of security needs. By moving beyond basic MFA requirements and leveraging advanced features like device compliance, risk-based policies, session controls, and third-party integrations, organizations can build a robust and secure access strategy for their cloud resources.

Remember to always test your Conditional Access policies thoroughly in Report-only mode before enabling them to ensure they function as expected and do not inadvertently block legitimate access. Continuous review and refinement of your policies are key to maintaining an effective security posture in the ever-evolving threat landscape.

Stay tuned for more insights on Azure security!