CVE-2020-0640
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on affected systems by exploiting memory corruption in Internet Explorer. Attackers can craft malicious web content that triggers the vulnerability when visited. Users running vulnerable versions of Internet Explorer on Windows systems are affected.
💻 Affected Systems
- Internet Explorer
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining same privileges as the logged-in user, potentially leading to data theft, ransomware deployment, or lateral movement.
Likely Case
Malicious website delivers malware payload that infects the user's system, leading to credential theft, data exfiltration, or botnet enrollment.
If Mitigated
Attack fails due to patch deployment, browser restrictions, or security controls blocking malicious content.
🎯 Exploit Status
Exploitation requires user interaction (visiting malicious website). No public proof-of-concept was released at disclosure.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: January 2020 Security Update
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0640
Restart Required: Yes
Instructions:
1. Apply Windows Update KB4528760 for Windows 10, KB4528762 for Windows 8.1/Server 2012 R2, KB4528763 for Windows 7/Server 2008 R2. 2. Restart system. 3. Verify Internet Explorer version is updated.
🔧 Temporary Workarounds
Disable Internet Explorer
windowsRemove or disable Internet Explorer as default browser
Optional: Use Group Policy to disable IE or set alternative default browser
Enhanced Security Configuration
windowsEnable Internet Explorer Enhanced Security Configuration on servers
Server Manager -> Local Server -> IE Enhanced Security Configuration -> Enable
🧯 If You Can't Patch
- Block malicious websites using web filtering/proxy solutions
- Implement application whitelisting to prevent unauthorized code execution
🔍 How to Verify
Check if Vulnerable:
Check Internet Explorer version: Help -> About Internet Explorer. If version is 9, 10, or 11 and January 2020 patch not installed, system is vulnerable.Check Version:
Run 'winver' or check Settings -> System -> About for Windows version and build numberVerify Fix Applied:
Verify Windows Update history shows KB4528760, KB4528762, or KB4528763 installed. Check Internet Explorer version includes January 2020 updates.📡 Detection & Monitoring
Log Indicators:
- Internet Explorer crash events in Windows Event Log
- Unexpected process execution following IE usage
- Suspicious network connections from iexplore.exe
Network Indicators:
- Outbound connections to known malicious domains from user workstations
- Unusual HTTP traffic patterns from IE processes
SIEM Query:
EventID=1000 OR EventID=1001 SourceName=Application Error ProcessName=iexplore.exe