CVE-2023-38934
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on affected Tenda routers via a stack overflow in the formSetDeviceName function. Attackers can exploit this by sending specially crafted requests containing a malicious deviceId parameter. Users of Tenda F1203, FH1203, and FH1205 routers with vulnerable firmware versions are affected.
💻 Affected Systems
- Tenda F1203
- Tenda FH1203
- Tenda FH1205
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, lateral movement to connected devices, and botnet recruitment.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation prevents lateral movement.
🎯 Exploit Status
Public proof-of-concept available in GitHub repository. Exploitation requires network access to router's web interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
Check Tenda official website for firmware updates. If available, download and flash via web interface.
🔧 Temporary Workarounds
Network Segmentation
allIsolate affected routers in separate VLANs with strict firewall rules.
Access Control
linuxBlock external access to router web interface (port 80/443) at network perimeter.
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Replace affected devices with patched or alternative models
- Implement strict network monitoring for unusual traffic patterns from router IPs
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface at 192.168.0.1 or 192.168.1.1Check Version:
curl -s http://router-ip/login/Auth | grep firmwareVerify Fix Applied:
Verify firmware version is newer than affected versions listed📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to formSetDeviceName endpoint
- Multiple failed authentication attempts followed by successful exploitation
Network Indicators:
- Unusual outbound connections from router IP
- Traffic spikes on router management ports
SIEM Query:
source="router_logs" AND (uri="/goform/setDeviceName" OR uri="/formSetDeviceName") AND deviceId=*