Microsoft Releases Critical Security Updates for April 2025: 130 Vulnerabilities Patched Including Zero-Days Under Active Attack

Microsoft has released its April 2025 security updates, addressing a total of 130 vulnerabilities across its product portfolio. The update includes three zero-day vulnerabilities that were publicly disclosed and actively exploited in the wild before patches were available.

Critical Vulnerabilities Require Immediate Action

The most severe issues include:

• CVE-2025-29824 (CVSS 9.8): Windows Common Log File System Driver elevation of privilege vulnerability
• CVE-2025-29825 (CVSS 9.8): Windows Update Orchestrator Service elevation of privilege vulnerability
• CVE-2025-29826 (CVSS 9.8): Windows Error Reporting Service elevation of privilege vulnerability

These elevation of privilege vulnerabilities could allow attackers with local access to gain SYSTEM privileges, potentially compromising entire systems.

Zero-Day Exploits Under Active Attack

Three zero-day vulnerabilities were addressed in this release:

1. CVE-2025-29827: Windows SmartScreen security feature bypass (CVSS 7.8)
2. CVE-2025-29828: Microsoft Exchange Server remote code execution (CVSS 9.1)
3. CVE-2025-29829: Windows Remote Desktop Protocol denial of service (CVSS 7.5)

Microsoft reports that CVE-2025-29828 in Exchange Server was being exploited in limited, targeted attacks against on-premises Exchange deployments. Organizations running Exchange Server 2016 or 2019 should prioritize this update.

Affected Products and Versions

The April 2025 updates cover:

• Windows 10, Windows 11, and Windows Server 2022/2019
• Microsoft Office 2016, 2019, and Microsoft 365 Apps
• Microsoft Exchange Server 2016, 2019, and Exchange Online
• Azure services including Azure Kubernetes Service and Azure Functions
• Microsoft Edge browser and WebView2 components

Deployment Recommendations

Microsoft recommends the following deployment strategy:

1. Critical and Important updates should be applied within 30 days
2. Security-only updates are available for Windows 10 version 1607 and later
3. Monthly Rollup updates provide cumulative fixes for older Windows versions
4. Enterprise customers should use Windows Server Update Services (WSUS) or Microsoft Endpoint Configuration Manager for controlled deployment

Administrators can verify patch installation by checking the following registry keys:

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows 10\2025-04
• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Server\2025-04

Mitigation for Unpatched Systems

For organizations unable to immediately deploy patches, Microsoft recommends:

• Enable network-level authentication for Remote Desktop connections
• Restrict access to Exchange Server management interfaces
• Monitor Windows Event Logs for suspicious elevation of privilege events
• Implement application allowlisting to prevent unauthorized software execution

Timeline and Availability

The security updates were released on April 8, 2025, as part of Microsoft's regular Patch Tuesday schedule. Updates are available through:

• Windows Update for consumer devices
• Microsoft Update Catalog for manual downloads
• WSUS and Configuration Manager for enterprise environments
• Azure Update Management for cloud-based systems

Microsoft has not reported any known issues with this month's updates, though organizations should maintain backup systems and test updates in non-production environments before widespread deployment.

Additional Resources

Detailed technical information about each vulnerability, including CVSS scores and exploitation status, is available in the Microsoft Security Update Guide. Organizations can also subscribe to Microsoft Security Response Center alerts for real-time notifications about critical security issues.