A critical Windows kernel vulnerability, tracked as CVE-2025-24983, has been actively exploited in the wild for nearly two years before being patched in Microsoft's March 2025 Patch Tuesday update. This use-after-free flaw in the Windows Kernel Memory Manager allows attackers to escalate privileges and gain SYSTEM-level access on vulnerable systems.

Understanding CVE-2025-24983

The vulnerability exists in how the Windows kernel handles certain memory management operations. Specifically, it involves improper handling of objects in memory that can lead to a use-after-free condition. This occurs when a program continues to use a pointer after the memory it references has been freed, potentially allowing attackers to execute arbitrary code in kernel mode.

Technical Analysis

  • Vulnerability Type: Use-after-free in ntoskrnl.exe
  • Attack Vector: Local privilege escalation
  • Impact: SYSTEM-level code execution
  • CVSS Score: 8.8 (High)
  • Affected Versions: Windows 10 1809+, Windows 11, Windows Server 2019/2022

Security researchers discovered that attackers have been combining this vulnerability with other exploits to bypass security mechanisms like User Account Control (UAC) and kernel-mode driver signing requirements.

Exploitation Timeline

Evidence suggests this vulnerability has been exploited since at least April 2023:

  • April 2023: First observed in targeted attacks
  • September 2024: Incorporated into popular exploit frameworks
  • January 2025: Mass scanning for vulnerable systems detected
  • March 2025: Officially patched by Microsoft

Detection and Mitigation

Indicators of Compromise (IoCs)

  • Unusual kernel-mode driver loads
  • Suspicious process creation from system processes
  • Memory allocation patterns matching known exploit chains

Temporary Mitigations

  1. Enable Attack Surface Reduction rules
  2. Restrict administrator privileges
  3. Monitor for unusual kernel API calls
  4. Implement driver blocklisting

Patch Tuesday Resolution

Microsoft addressed CVE-2025-24983 in the March 2025 security update (KB5035849) through:

  • Proper memory object handling
  • Additional validation checks
  • Improved reference counting

Lessons for Enterprise Security

This prolonged exploitation period highlights several critical security challenges:

  1. Patch Latency: Many organizations take months to deploy critical updates
  2. Detection Gaps: Kernel-level exploits often evade traditional security tools
  3. Supply Chain Risks: Compromised systems can affect entire networks

Best Practices Moving Forward

  • Implement a 30-day critical patch SLA
  • Deploy kernel-mode behavior monitoring
  • Conduct regular privilege access reviews
  • Enable memory integrity features in Windows Defender

Security professionals recommend treating this vulnerability as high priority due to its demonstrated exploitability and the sensitive nature of kernel-level access.