CVE-2025-49658
📋 TL;DR
This vulnerability allows a local authenticated attacker to read memory outside the intended buffer in Windows TDX.sys, potentially exposing sensitive information. It affects Windows systems with the Trusted Domain Extensions component enabled. Attackers need valid local credentials to exploit this flaw.
💻 Affected Systems
- Microsoft Windows
📦 What is this software?
Windows 10 1507 by Microsoft
Windows 10 1507 by Microsoft
Windows 10 1607 by Microsoft
Windows 10 1607 by Microsoft
Windows 10 1809 by Microsoft
Windows 10 1809 by Microsoft
Windows 10 21h2 by Microsoft
Windows 10 22h2 by Microsoft
Windows 11 22h2 by Microsoft
Windows 11 23h2 by Microsoft
Windows 11 24h2 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
An attacker could read kernel memory containing sensitive data like credentials, encryption keys, or other protected information, leading to privilege escalation or further system compromise.
Likely Case
Information disclosure of kernel memory contents, potentially revealing system state or configuration details that could aid in developing further attacks.
If Mitigated
Limited information disclosure with no direct code execution or system control, though exposed data could facilitate other attacks.
🎯 Exploit Status
Requires local authenticated access and knowledge of memory layout. No public exploits available as of current information.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Security Update Guide for specific KB numbers
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-49658
Restart Required: Yes
Instructions:
1. Apply the latest Windows security updates from Microsoft. 2. Restart the system to complete the installation. 3. Verify the patch is applied using Windows Update history or system information.
🔧 Temporary Workarounds
Disable TDX component
windowsDisable the Trusted Domain Extensions feature if not required for your environment
Disable via Windows Features or Group Policy: Turn off Windows Defender Credential Guard
🧯 If You Can't Patch
- Implement strict access controls to limit local administrative privileges
- Monitor for unusual local privilege escalation attempts and memory access patterns
🔍 How to Verify
Check if Vulnerable:
Check Windows version and installed updates. Systems without the security patch for CVE-2025-49658 are vulnerable.Check Version:
wmic os get caption, version, buildnumber, csdversionVerify Fix Applied:
Verify the security update is installed via Windows Update history or by checking system version against patched versions.📡 Detection & Monitoring
Log Indicators:
- Unusual kernel memory access patterns
- Failed attempts to access protected memory regions
- Security event logs showing privilege escalation attempts
Network Indicators:
- Not applicable - this is a local vulnerability
SIEM Query:
EventID=4688 OR EventID=4656 with process names accessing kernel memory regions