CVE-2025-12236
📋 TL;DR
A buffer overflow vulnerability in Tenda CH22 routers allows remote attackers to execute arbitrary code by manipulating the 'page' parameter in the DHCP client list function. This affects Tenda CH22 routers running firmware version 1.0.0.1. Remote exploitation is possible without authentication.
💻 Affected Systems
- Tenda CH22
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, network infiltration, and potential lateral movement to other devices.
Likely Case
Remote code execution allowing attackers to install malware, create backdoors, or use the device for botnet activities.
If Mitigated
Denial of service or device crash if exploit fails to achieve code execution.
🎯 Exploit Status
Public exploit available on GitHub, making exploitation straightforward for attackers.
🛠️ 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 System Tools > Firmware Upgrade. 5. Upload and install new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to the vulnerable web interface
Log into router admin > System Tools > Remote Management > Disable
Network Segmentation
allIsolate router management interface from untrusted networks
Configure firewall rules to block external access to router management ports (typically 80, 443, 8080)
🧯 If You Can't Patch
- Replace affected Tenda CH22 router with a different model or vendor
- Place router behind a dedicated firewall with strict inbound rules
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface: System Status > Firmware VersionCheck Version:
curl -s http://router-ip/ | grep -i firmwareVerify Fix Applied:
Verify firmware version is no longer 1.0.0.1 after update📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/DhcpListClient
- Multiple buffer overflow attempts in web logs
- Router crash/reboot events
Network Indicators:
- Exploit traffic patterns to router management interface
- Unusual outbound connections from router
SIEM Query:
source="router_logs" AND (uri="/goform/DhcpListClient" OR message="buffer overflow")