CVE-2023-31986
📋 TL;DR
A command injection vulnerability in Edimax N300 router firmware allows unauthenticated attackers to execute arbitrary system commands via the setWAN function. This affects Edimax BR-6428NS_v4 routers with vulnerable firmware, potentially giving attackers full control of affected devices.
💻 Affected Systems
- Edimax Wireless Router N300
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router compromise allowing attackers to intercept all network traffic, install persistent malware, pivot to internal networks, and use the router as a botnet node.
Likely Case
Router takeover leading to DNS hijacking, credential theft from network traffic, and installation of backdoors for persistent access.
If Mitigated
Limited impact if router is behind firewall with restricted WAN access and command execution is properly sanitized.
🎯 Exploit Status
Exploit requires sending crafted HTTP requests to the router's web interface. No authentication needed, making exploitation trivial.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not found in provided references
Restart Required: Yes
Instructions:
1. Check Edimax website for firmware updates
2. Download latest firmware for BR-6428NS_v4
3. Access router admin interface
4. Navigate to firmware update section
5. Upload and apply new firmware
6. Reboot router
🔧 Temporary Workarounds
Disable WAN Management
allPrevent external access to router management interface
Access router admin > Security > Remote Management > Disable
Network Segmentation
allIsolate router management interface to separate VLAN
🧯 If You Can't Patch
- Replace affected routers with supported models
- Implement strict firewall rules blocking all external access to router management ports (typically 80, 443, 8080)
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router admin interface. If running BR-6428NS_v4 firmware and no recent updates, assume vulnerable.Check Version:
curl -s http://router-ip/ | grep -i firmware || Access router web interface and check System StatusVerify Fix Applied:
Verify firmware version has been updated to a version after the vulnerability disclosure (check Edimax security advisories).📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /bin/webs with command injection patterns
- Multiple failed login attempts followed by successful command execution
- Unexpected system command execution in router logs
Network Indicators:
- Unusual outbound connections from router to unknown IPs
- DNS queries to suspicious domains from router
- Unexpected traffic patterns from router WAN interface
SIEM Query:
source="router_logs" AND (uri="/bin/webs" AND (method="POST" AND (content="setWAN" AND content="$" OR content="|" OR content="`")))