CVE-2019-1140
📋 TL;DR
This is a remote code execution vulnerability in Microsoft Edge's Chakra JavaScript engine that allows attackers to execute arbitrary code by tricking users into visiting malicious websites. It affects users running vulnerable versions of Microsoft Edge on Windows systems. Successful exploitation gives attackers the same privileges as the current user.
💻 Affected Systems
- Microsoft Edge (HTML-based)
📦 What is this software?
Edge by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with administrative privileges, allowing installation of malware, data theft, and creation of new accounts.
Likely Case
Malware installation and data theft from the current user's account, potentially leading to credential harvesting and lateral movement.
If Mitigated
Limited impact due to browser sandboxing and user account restrictions, but still significant data exposure risk.
🎯 Exploit Status
Exploitation requires user interaction but no authentication. Memory corruption vulnerability in JavaScript engine.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: August 2019 security update for Microsoft Edge
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1140
Restart Required: Yes
Instructions:
1. Open Windows Update settings. 2. Check for updates. 3. Install August 2019 security updates. 4. Restart system if prompted.
🔧 Temporary Workarounds
Disable JavaScript
windowsDisable JavaScript in Microsoft Edge to prevent exploitation
Use Application Guard
windowsEnable Microsoft Defender Application Guard for Edge to isolate browsing sessions
🧯 If You Can't Patch
- Switch to Chromium-based Microsoft Edge or alternative browsers
- Implement network filtering to block known malicious websites and restrict internet access
🔍 How to Verify
Check if Vulnerable:
Check Microsoft Edge version in Settings > About Microsoft Edge. If version is from before August 2019, system is vulnerable.Check Version:
msedge --versionVerify Fix Applied:
Verify Windows Update history shows August 2019 security updates installed and Edge version is updated.📡 Detection & Monitoring
Log Indicators:
- Unusual process creation from Microsoft Edge
- Suspicious network connections from browser process
Network Indicators:
- Outbound connections to known malicious domains from browser
- Unusual JavaScript execution patterns
SIEM Query:
Process Creation where ParentImage contains 'msedge.exe' and CommandLine contains unusual patterns