Implementing Conditional Access for Azure Virtual Desktop

Azure Virtual Desktop without Conditional Access is like leaving your front door unlocked. Sure, you have a key, but anyone who finds it can walk right in.

Why Conditional Access Matters for AVD

AVD gives users access to corporate desktops and applications from anywhere. That's powerful — and risky.

Without proper controls, a compromised credential means an attacker has the same access as your legitimate user. From any device. From any location.

Conditional Access lets you add context to authentication:

Where is the user connecting from?
What device are they using?
How risky is this sign-in?
What are they trying to access?

The Policies You Actually Need

1. Require MFA for All AVD Connections

This is non-negotiable. Every AVD connection should require multi-factor authentication.

Target these apps:

Azure Virtual Desktop (9cdead84-a844-4324-93f2-b2e6bb768d07)
Microsoft Remote Desktop (a4a365df-50f1-4397-bc59-1a1564b8bb9c)
Windows 365 (0af06dc6-e4b5-4f28-818e-e78e62d137a5)

Don't just target one — users connect through different clients, and you need coverage across all of them.

2. Block Legacy Authentication

Legacy authentication protocols don't support MFA. Block them entirely for AVD workloads.

This catches older RDP clients that might bypass your modern auth policies.

3. Require Compliant or Hybrid Joined Devices

If you're running Intune, require device compliance. This ensures:

Devices have up-to-date security patches
Antivirus is running and current
Disk encryption is enabled
No jailbroken or rooted devices

For organizations with on-premises AD, hybrid Azure AD join gives you similar assurance.

4. Location-Based Restrictions

Consider blocking connections from countries where you don't operate. Or require additional verification for connections outside your corporate network.

Named locations make this easy to manage.

Common Mistakes to Avoid

Targeting the Wrong Apps

AVD has multiple app IDs. Miss one, and you've left a gap. Always include:

Azure Virtual Desktop
Microsoft Remote Desktop
Windows Cloud Login (for Windows 11 multi-session)

Forgetting About Service Accounts

If you have service accounts or break-glass accounts, exclude them carefully. But make sure those exclusions are monitored and logged.

Not Testing First

Use Report-only mode before enforcing. Watch the sign-in logs. See what would have been blocked. Then enable enforcement when you're confident.

The Implementation Order

Start with Report-only — Deploy policies in report-only mode
Monitor for a week — Check sign-in logs for unexpected blocks
Communicate to users — Let them know MFA is coming
Enable enforcement — Switch from report-only to on
Monitor again — Watch for help desk tickets and adjust

Beyond Basic Policies

Once you have the basics, consider:

Sign-in risk policies — Block or require MFA for risky sign-ins detected by Identity Protection
Session controls — Limit session duration or require re-authentication
App protection policies — Control what users can do within AVD sessions

The Bottom Line

Conditional Access isn't optional for AVD deployments. It's the difference between "we have remote desktops" and "we have secure remote desktops."

Start with MFA everywhere. Add device compliance. Layer in location and risk-based policies. Monitor continuously.

Your security team will thank you. Your auditors definitely will.