CVE-2025-8180
📋 TL;DR
A critical buffer overflow vulnerability in Tenda CH22 routers allows remote attackers to execute arbitrary code by manipulating the 'old_account' parameter in the formdeleteUserName function. This affects Tenda CH22 version 1.0.0.1 routers with the vulnerable firmware. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 Affected Systems
- Tenda CH22
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, lateral movement to internal networks, persistent backdoor installation, and data exfiltration.
Likely Case
Remote code execution resulting in device takeover, denial of service, or credential theft from connected devices.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering, though internal exploitation remains possible.
🎯 Exploit Status
Exploit details are publicly available on GitHub, making weaponization straightforward. The buffer overflow manipulation is well-documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.tenda.com.cn/
Restart Required: Yes
Instructions:
1. Check Tenda's official website for firmware updates. 2. If available, download the latest firmware for CH22. 3. Access router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply the new firmware. 6. Reboot the router.
🔧 Temporary Workarounds
Network Segmentation and Access Control
linuxRestrict access to the router's web interface and administrative endpoints
iptables -A INPUT -p tcp --dport 80 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
Disable Remote Administration
allTurn off remote management features to prevent external exploitation
🧯 If You Can't Patch
- Isolate affected routers in a dedicated VLAN with strict firewall rules blocking all unnecessary traffic
- Implement network monitoring for exploitation attempts targeting /goform/deleteUserName endpoint
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface. If version is 1.0.0.1, the device is vulnerable.Check Version:
curl -s http://router-ip/login/Auth | grep -i version || Check web interface System Status pageVerify Fix Applied:
After firmware update, verify version is no longer 1.0.0.1. Test if /goform/deleteUserName endpoint still accepts malformed old_account parameters.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /goform/deleteUserName with unusually long old_account parameters
- Router crash/restart logs following web interface access
Network Indicators:
- HTTP traffic to router IP on port 80 with POST to /goform/deleteUserName containing buffer overflow patterns
- Unusual outbound connections from router after exploitation
SIEM Query:
source="router_logs" AND url="/goform/deleteUserName" AND (param_length>100 OR contains(param,"AAAAAAAA"))