CVE-2020-0970
📋 TL;DR
This is a remote code execution vulnerability in Microsoft's ChakraCore JavaScript engine that allows attackers to execute arbitrary code by exploiting memory corruption. It affects systems running vulnerable versions of Microsoft Edge and applications using ChakraCore. Attackers could gain the same user rights as the current user.
💻 Affected Systems
- Microsoft Edge
- ChakraCore
📦 What is this software?
Chakracore by Microsoft
Edge by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control over the affected system, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Arbitrary code execution in the context of the current user, potentially leading to malware installation, credential theft, or browser session hijacking.
If Mitigated
Limited impact due to sandboxing in modern browsers, but still potentially dangerous if combined with other vulnerabilities or in non-browser ChakraCore implementations.
🎯 Exploit Status
Exploitation requires user interaction (visiting a malicious website) but no authentication. Memory corruption vulnerabilities in scripting engines are commonly exploited in the wild.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: April 2020 security updates for Windows 10 and Windows Server
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0970
Restart Required: Yes
Instructions:
1. Apply Windows Update for April 2020 or later. 2. For Microsoft Edge, update through Windows Update. 3. For ChakraCore, update to a patched version. 4. Restart the system after applying updates.
🔧 Temporary Workarounds
Disable JavaScript
windowsDisable JavaScript in Microsoft Edge to prevent exploitation through web content
Use Chromium-based Edge
windowsSwitch to Chromium-based Microsoft Edge which is not affected by this vulnerability
🧯 If You Can't Patch
- Restrict access to untrusted websites and implement web filtering
- Use application whitelisting to prevent unauthorized code execution
🔍 How to Verify
Check if Vulnerable:
Check Microsoft Edge version: Open Edge → Settings → About Microsoft Edge. If version is before the April 2020 update, system is vulnerable.Check Version:
In Edge browser: edge://settings/help or check Windows Update historyVerify Fix Applied:
Verify Windows Update history shows April 2020 security updates installed and Microsoft Edge version is updated.📡 Detection & Monitoring
Log Indicators:
- Unexpected process creation from Microsoft Edge
- Memory access violations in ChakraCore
- Crash reports from Microsoft Edge
Network Indicators:
- Unusual outbound connections from Microsoft Edge process
- Traffic to known malicious domains
SIEM Query:
Process Creation where (Image contains 'MicrosoftEdge' OR ParentImage contains 'MicrosoftEdge') AND CommandLine contains suspicious patterns