CVE-2023-49427
📋 TL;DR
A buffer overflow vulnerability in Tenda AX12 routers allows remote attackers to cause denial of service by sending specially crafted requests to the SetNetControlList function. This affects Tenda AX12 routers running firmware version V22.03.01.46. Attackers can crash the device or potentially execute arbitrary code.
💻 Affected Systems
- Tenda AX12
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, persistent backdoor installation, and lateral movement to connected networks.
Likely Case
Denial of service causing router reboot or crash, disrupting network connectivity for all connected devices.
If Mitigated
Limited to DoS with proper network segmentation and firewall rules blocking external access to router management interfaces.
🎯 Exploit Status
Public proof-of-concept demonstrates exploitation via HTTP POST request with oversized list parameter. No authentication required.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates. 2. Download latest firmware for AX12. 3. Access router admin interface. 4. Navigate to System Tools > Firmware Upgrade. 5. Upload and install new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to router web interface
Access router admin > Advanced > System Tools > Remote Management > Disable
Block management interface ports
linuxFirewall rules to block access to router web interface
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Segment router management interface to isolated VLAN
- Implement strict firewall rules allowing only trusted IPs to access router management
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router admin interface under System Status or System ToolsCheck Version:
curl -s http://router-ip/ | grep -i firmware || Check web interface manuallyVerify Fix Applied:
Verify firmware version is different from V22.03.01.46 after update📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /goform/SetNetControlList with large payloads
- Router crash/reboot logs
- Unusual traffic to router management interface
Network Indicators:
- HTTP requests with oversized list parameters to router IP
- Multiple connection attempts to router port 80/443
SIEM Query:
source="router.log" AND ("SetNetControlList" OR "POST /goform/" AND content_length>1000)