CVE-2019-1315
📋 TL;DR
This vulnerability allows attackers to elevate privileges on Windows systems by exploiting improper handling of hard links in Windows Error Reporting Manager. It affects Windows 10, Windows Server 2016, and Windows Server 2019 systems. An authenticated attacker could gain SYSTEM-level privileges.
💻 Affected Systems
- Windows 10
- Windows Server 2016
- Windows Server 2019
📦 What is this software?
Windows 10 1607 by Microsoft
Windows 10 1703 by Microsoft
Windows 10 1709 by Microsoft
Windows 10 1803 by Microsoft
Windows 10 1809 by Microsoft
Windows 10 1903 by Microsoft
Windows 7 by Microsoft
Windows 8.1 by Microsoft
Windows Rt 8.1 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with SYSTEM privileges, enabling installation of malware, data theft, and lateral movement across the network.
Likely Case
Local privilege escalation allowing attackers to bypass security controls, install persistent backdoors, or access sensitive system resources.
If Mitigated
Limited impact with proper patch management and least privilege principles in place, though still a serious local vulnerability.
🎯 Exploit Status
Exploit code is publicly available and relatively simple to execute. Requires local access to the target system.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: October 2019 security updates (KB4517389 for Windows 10 1903, KB4519338 for 1809, etc.)
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1315
Restart Required: Yes
Instructions:
1. Apply October 2019 Windows security updates via Windows Update. 2. For enterprise environments, deploy through WSUS or SCCM. 3. Restart affected systems after patch installation.
🔧 Temporary Workarounds
Disable Windows Error Reporting Service
windowsTemporarily disable the vulnerable service to prevent exploitation
sc config WerSvc start= disabled
sc stop WerSvc
🧯 If You Can't Patch
- Implement strict least privilege principles to limit initial access
- Monitor for suspicious WerSvc service activity and hard link creation
🔍 How to Verify
Check if Vulnerable:
Check if October 2019 security updates are installed via 'wmic qfe list' or 'systeminfo' commandCheck Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify KB4517389 (or relevant October 2019 update) is installed and WerSvc service is running normally📡 Detection & Monitoring
Log Indicators:
- Event ID 4697 (Service installed) for WerSvc modifications
- Unexpected hard link creation in system directories
Network Indicators:
- No specific network indicators - local exploitation only
SIEM Query:
EventID=4697 AND ServiceName="WerSvc" AND (SubjectUserName!="SYSTEM" OR ProcessName contains suspicious patterns)