CVE-2025-1896
📋 TL;DR
A critical buffer overflow vulnerability in Tenda TX3 routers allows remote attackers to execute arbitrary code by sending specially crafted requests to the /goform/SetStaticRouteCfg endpoint. This affects Tenda TX3 routers running firmware version 16.03.13.11_multi. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 Affected Systems
- Tenda TX3
📦 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
Device takeover enabling network traffic interception, DNS hijacking, credential theft, and use as botnet node.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and proper network segmentation.
🎯 Exploit Status
Public exploit proof-of-concept available in GitHub repository. Attack requires sending crafted HTTP POST request to vulnerable endpoint.
🛠️ 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. Access router admin interface. 4. Navigate to System Tools > Firmware Upgrade. 5. Upload and install new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Network Access Control
linuxBlock external access to router web interface using firewall rules
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
Endpoint Restriction
allDisable remote administration and restrict web interface to internal network only
🧯 If You Can't Patch
- Isolate affected routers in separate VLAN with strict firewall rules
- Implement network monitoring for unusual traffic patterns to/from router management interface
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System Status or System Tools > Firmware UpgradeCheck Version:
curl -s http://router-ip/ | grep -i firmware || Check web interface manuallyVerify Fix Applied:
Verify firmware version is no longer 16.03.13.11_multi and test if /goform/SetStaticRouteCfg endpoint rejects malformed requests📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /goform/SetStaticRouteCfg with long parameters
- Router crash/reboot logs
- Unusual process execution in system logs
Network Indicators:
- HTTP POST requests to router IP on port 80/443 with oversized 'list' parameter
- Unusual outbound connections from router
SIEM Query:
source="router_logs" AND (url="/goform/SetStaticRouteCfg" AND content_length>1000) OR process="unexpected_executable"