Overview
Following the release of Microsoft’s April 2024 Patch Tuesday updates, administrators across the globe are reporting unexpected issues with Windows Server authentication. These problems are impacting domain controllers and are causing authentication failures across various services, potentially disrupting business operations. If your IT team has recently patched Windows Server environments, here’s what you need to know.
What’s Causing the Authentication Issues?
The core of the issue lies in updates delivered to Windows Server 2016, 2019, and 2022 during the April 2024 Patch Tuesday rollout. After deployment, organizations began reporting authentication problems when users attempted to log into services that rely on AD (Active Directory), including:
- Remote Desktop Services (RDS)
- VPN connections
- File shares and network drives
- Other internal enterprise applications
Early investigations suggest the issues are related to changes made to the Local Security Authority (LSA) and how credentials are validated when users attempt to log in or access network resources.
Affected Systems
The known affected server versions include:
- Windows Server 2016
- Windows Server 2019
- Windows Server 2022
While authentication failures are the most-visible problem, some systems have also experienced service crashes, credential lockouts, and event log warnings related to the LSASS.exe process.
Microsoft’s Response and Guidance
Microsoft has acknowledged the bug and confirmed that the April updates can cause authentication disruptions in certain scenarios. Currently, the company is collecting data and working on a resolution. In the meantime, they recommend affected administrators review the following actions:
- Temporarily roll back updates: If authentication failures are widespread, uninstalling the April updates may restore stability.
- Use known workaround configurations: Microsoft has published workaround guidance via their official documentation and known issue tracker for each update.
- Report incidents: Microsoft is urging IT admins to open support cases to help fast-track their telemetry and diagnosis efforts.
Potential Security Trade-offs
Although rolling back updates seems like a viable quick fix, organizations must carefully weigh the security risks. The April updates include critical security patches for actively exploited vulnerabilities, such as remote code execution flaws and privilege escalation bugs. Downgrading or removing these updates may reopen your systems to attackers.
Best Practices for IT Teams
Here are a few steps IT departments should consider to mitigate risk:
- Test patches in staging environments before rolling them out to production systems.
- Closely monitor authentication logs and LSASS-related errors after applying updates.
- Keep your backups up to date to allow rapid recovery in case of failure.
- Stay updated on Microsoft’s advisories by subscribing to their security bulletins or RSS feeds.
Conclusion
The Windows Server authentication issues stemming from the April 2024 updates highlight the delicate balance between security and system stability. While Microsoft is working to develop a fix, system administrators should proceed cautiously, implement temporary mitigations, and stay informed of official updates. Widespread enterprise authentication failures can grind operations to a halt—so proactive planning and swift response remain essential in maintaining IT infrastructure integrity.