CVE-2024-8226
📋 TL;DR
This critical vulnerability in Tenda O1 routers allows remote attackers to execute arbitrary code via a stack-based buffer overflow in the formSetCfm function. Attackers can exploit this without authentication to potentially take full control of affected devices. All users of Tenda O1 routers running version 1.0.0.7(10648) are affected.
💻 Affected Systems
- Tenda O1
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, lateral movement to other 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 device is behind firewall with strict inbound rules, though internal network compromise remains possible if exploited.
🎯 Exploit Status
Public exploit details are available in GitHub repositories. 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. Download latest firmware. 3. Log into router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable remote administration
allPrevent external access to router web interface
Firewall blocking
linuxBlock inbound access to router web interface ports (typically 80, 443, 8080)
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
iptables -A INPUT -p tcp --dport 8080 -j DROP
🧯 If You Can't Patch
- Replace vulnerable router with different model/brand
- Place router behind dedicated firewall with strict inbound rules
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface. If version is exactly 1.0.0.7(10648), device is vulnerable.Check Version:
Check router web interface at http://router-ip/ or use nmap scan to identify device model and versionVerify Fix Applied:
Verify firmware version has changed from 1.0.0.7(10648) to a newer version after update.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/setcfm
- Multiple failed buffer overflow attempts
- Unexpected router configuration changes
Network Indicators:
- Traffic to router IP on port 80 with unusual payload sizes
- Outbound connections from router to unknown IPs
SIEM Query:
source="router_logs" AND (uri="/goform/setcfm" OR message="buffer overflow")