CVE-2019-0667
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on affected Windows systems by exploiting a memory handling flaw in the VBScript engine. Attackers could compromise systems by tricking users into visiting malicious websites or opening specially crafted documents. This affects Windows systems with VBScript enabled.
💻 Affected Systems
- Microsoft Windows
- Internet Explorer
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with administrative privileges, data theft, ransomware deployment, and lateral movement across networks.
Likely Case
Malware installation, credential theft, and system compromise through drive-by downloads or malicious documents.
If Mitigated
Limited impact due to application sandboxing, reduced privileges, and network segmentation preventing lateral movement.
🎯 Exploit Status
Exploitation requires user interaction (visiting malicious website or opening document). No public exploit code was available at disclosure.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: March 2019 security updates
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0667
Restart Required: Yes
Instructions:
1. Apply March 2019 Windows security updates via Windows Update. 2. For enterprise: Deploy through WSUS or SCCM. 3. Verify update installation with systeminfo or Get-Hotfix.
🔧 Temporary Workarounds
Disable VBScript in Internet Explorer
windowsPrevents VBScript execution in Internet Explorer, mitigating web-based attacks.
Set-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{B54F3741-5B07-11CF-A4B0-00AA004A55E8}" -Name "Compatibility Flags" -Value 0x400
Restrict Internet Explorer to trusted sites
windowsLimits VBScript execution to approved websites only.
🧯 If You Can't Patch
- Implement application whitelisting to prevent unauthorized code execution
- Use Microsoft Enhanced Mitigation Experience Toolkit (EMET) or Windows Defender Exploit Guard
🔍 How to Verify
Check if Vulnerable:
Check if March 2019 security updates are installed via systeminfo or Get-Hotfix -Id KB4489878, KB4489886Check Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify security update KB4489878 (Windows 10) or KB4489886 (Windows 7/8.1/Server) is installed📡 Detection & Monitoring
Log Indicators:
- Internet Explorer crash logs with VBScript errors
- Windows Event Logs showing script execution failures
- Unexpected process creation from iexplore.exe
Network Indicators:
- HTTP requests to known malicious domains delivering VBScript content
- Unusual outbound connections from user workstations
SIEM Query:
source="windows" event_id=1000 process_name="iexplore.exe" message="VBScript"