CVE-2024-8224
📋 TL;DR
This critical vulnerability in Tenda G3 routers allows remote attackers to execute arbitrary code via a stack-based buffer overflow in the formSetDebugCfg function. Attackers can exploit this without authentication to potentially take full control of affected devices. All users running Tenda G3 firmware version 15.11.0.20 are affected.
💻 Affected Systems
- Tenda G3 router
📦 What is this software?
G3 Firmware by Tendacn
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing persistent backdoor installation, network traffic interception, lateral movement to internal networks, and botnet recruitment.
Likely Case
Remote code execution leading to device takeover, credential theft, and use as pivot point for internal network attacks.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Detailed exploit documentation is publicly available on GitHub. The vulnerability requires no authentication and has straightforward exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.tenda.com.cn/
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates. 2. If update available, download and install via web interface. 3. Reboot router after update. Note: Vendor has not responded to disclosure.
🔧 Temporary Workarounds
Block access to vulnerable endpoint
linuxUse firewall rules to block access to /goform/setDebugCfg endpoint
iptables -A INPUT -p tcp --dport 80 -m string --string "/goform/setDebugCfg" --algo bm -j DROP
iptables -A INPUT -p tcp --dport 443 -m string --string "/goform/setDebugCfg" --algo bm -j DROP
Disable remote administration
allTurn off remote management features in router settings
🧯 If You Can't Patch
- Isolate affected routers in separate VLAN with strict firewall rules
- Implement network segmentation to limit lateral movement if device is compromised
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in web interface. If version is 15.11.0.20, device is vulnerable.Check Version:
curl -s http://router-ip/ | grep -i firmware || Check web interface at http://router-ip/Verify Fix Applied:
Verify firmware version has changed from 15.11.0.20 to a newer version.📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /goform/setDebugCfg with long parameter values
- Unusual process execution or memory errors in router logs
Network Indicators:
- HTTP POST requests to /goform/setDebugCfg with oversized enable/level/module parameters
- Unusual outbound connections from router
SIEM Query:
http.url:"/goform/setDebugCfg" AND http.method:POST AND (http.request.body:"enable=" OR http.request.body:"level=" OR http.request.body:"module=")