Addressing the Intune Policy Reset Bug—A Practical Roadmap

Earlier this month, administrators worldwide discovered that a routine update to Microsoft Intune was inadvertently resetting custom device configuration policies. For organisations that rely on Intune to enforce security baselines—such as firewall rules, BitLocker encryption, and compliance settings—this bug introduced both risk and operational overhead. In this article, we’ll examine how to mitigate the immediate impact and build processes to guard against similar disruptions in the future.

Understanding the Root Cause

Microsoft engineers traced the issue to a change in the underlying policy serialisation engine. Custom settings defined via XML templates were not being correctly merged during schema validation, causing Intune to revert to default values at each policy sync. While Microsoft released a hotfix within a week, the incident underscores the importance of resilient policy management.

Interim Mitigation Strategies

1. Policy Backups: Export all custom configuration profiles to a secure repository (e.g., Azure Blob Storage) whenever changes are made. Automate using PowerShell scripts to run nightly exports of Get-IntuneDeviceConfigurationPolicy objects.

2. Change Monitoring: Implement change-detection alerts. Use Microsoft Graph API webhooks or Azure Monitor to flag unexpected modifications in critical policies. A simple Azure Function can compare nightly snapshots against live configurations and notify the security team if discrepancies appear.

3. Staged Rollouts: Before pushing updates universally, pilot policy changes on a small group of non-critical test devices. Validate that custom settings persist across Intune service updates and device reboots.

Permanent Best Practices

• Infrastructure as Code: Define device configurations using declarative templates stored in source control (e.g., Azure ARM templates or Terraform). Treat infrastructure and device policies like application code—enforce pull requests, code reviews, and automated testing.

• Automated Testing Framework: Develop a lab environment mirroring production. Use Azure DevOps pipelines to deploy policy definitions to test tenants and run scripts that validate key settings. Incorporate this into your CI/CD pipeline so that every policy change triggers automated verification.

• Resilience Through Redundancy: For critical security controls (firewall, encryption), layer additional enforcement mechanisms. Windows built-in firewall rules via Group Policy or Device Guard can backstop Intune configurations in case of service anomalies.

Working with Microsoft Support

Timely engagement with Microsoft Support and Premier services can accelerate resolution. When opening a case, provide detailed logs from device management diagnostics and policy merge trace logs. Ask for insights into planned fixes and timelines, and request early access to preview builds when available.

While the Intune policy reset bug created a scramble for administrators, it also offers lessons in policy resilience. By treating device configurations as code, automating backups and testing, and establishing change-monitoring processes, organisations can turn a costly incident into an opportunity to mature their endpoint management practices. In an era where endpoints serve as the front line of defense, ensuring policy integrity is non-negotiable—and these strategies will help maintain continuity and security even when service hiccups occur.