CVE-2023-31983
📋 TL;DR
This CVE describes a critical command injection vulnerability in Edimax N300 wireless router firmware that allows unauthenticated attackers to execute arbitrary system commands via the mp function in the webs binary. Attackers can gain complete control of affected routers. All users of Edimax BR-6428NS_v4 routers with vulnerable firmware are affected.
💻 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 part of botnets or for cryptocurrency mining.
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 routers are behind firewalls with strict inbound filtering and network segmentation prevents lateral movement.
🎯 Exploit Status
The vulnerability requires no authentication and has publicly available proof-of-concept code, making it trivial for attackers to exploit.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Edimax support 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 after update
🔧 Temporary Workarounds
Disable WAN Management
allPrevent external access to router management interface
Access router admin panel -> Security -> Remote Management -> Disable
Network Segmentation
allIsolate router management interface to separate VLAN
🧯 If You Can't Patch
- Replace affected routers with supported models from different vendors
- Place routers behind dedicated firewalls with strict inbound filtering rules
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface (typically under System Status or About) and compare with known vulnerable versionsCheck Version:
curl -s http://router-ip/status.asp | grep -i firmware || ssh admin@router-ip 'cat /proc/version'Verify Fix Applied:
Verify firmware version has been updated to a version not listed in vulnerability reports📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Multiple failed authentication attempts to webs service
- Suspicious processes running with root privileges
Network Indicators:
- Unexpected outbound connections from router
- DNS queries to malicious domains
- Port scans originating from router
SIEM Query:
source="router_logs" AND (process="webs" AND command="*;*" OR command="*|*" OR command="*`*" OR command="*$(*")