CVE-2019-0806
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on affected systems by exploiting memory corruption in Microsoft Edge's Chakra JavaScript engine. Attackers can compromise systems by tricking users into visiting malicious websites. Users of Microsoft Edge on Windows 10 are primarily affected.
💻 Affected Systems
- Microsoft Edge
📦 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 victim's computer, enabling data theft, ransomware deployment, or persistent backdoor installation.
Likely Case
Browser compromise leading to session hijacking, credential theft, and installation of malware or spyware on the victim's system.
If Mitigated
Limited impact with browser sandbox escape prevented, though browser data may still be compromised.
🎯 Exploit Status
Exploitation requires user interaction (visiting malicious website). Memory corruption vulnerabilities in browsers are frequently weaponized in exploit kits.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: March 2019 security updates (KB4489873 for Windows 10 1809, KB4489886 for Windows 10 1803, etc.)
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0806
Restart Required: Yes
Instructions:
1. Open Windows Update settings. 2. Check for updates. 3. Install March 2019 security updates. 4. Restart computer. 5. Verify Edge version is updated.
🔧 Temporary Workarounds
Disable JavaScript
windowsPrevents exploitation by disabling JavaScript execution in Edge
edge://settings/content/javascript (toggle to Blocked)
Use Application Control
windowsRestrict execution of untrusted applications via Windows Defender Application Control
Configure via Group Policy or Windows Security Center
🧯 If You Can't Patch
- Migrate to Chromium-based Microsoft Edge which is not affected by this vulnerability
- Implement network filtering to block known malicious websites and restrict browser usage to trusted sites only
🔍 How to Verify
Check if Vulnerable:
Check Edge version: Open Edge → Settings → About Microsoft Edge. If version is before the March 2019 updates, system is vulnerable.Check Version:
msedge --version (in command prompt) or check edge://settings/helpVerify Fix Applied:
Verify Windows Update history shows March 2019 security updates installed and Edge version is updated.📡 Detection & Monitoring
Log Indicators:
- Edge crash reports with memory access violations
- Unexpected Edge child processes spawning
- Suspicious JavaScript execution patterns
Network Indicators:
- Connections to known exploit kit domains
- Unusual outbound traffic from Edge process
SIEM Query:
source="Windows Security" EventID=4688 AND NewProcessName="*\MicrosoftEdge*.exe" AND ParentProcessName="*\MicrosoftEdge*.exe"