CVE-2025-44866
📋 TL;DR
This CVE describes a command injection vulnerability in Tenda W20E routers that allows attackers to execute arbitrary commands on the device. Attackers can exploit this by sending specially crafted requests to the vulnerable formSetDebugCfg function. This affects users running Tenda W20E routers with firmware version V15.11.0.6.
💻 Affected Systems
- Tenda W20E
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attackers to install persistent backdoors, intercept network traffic, pivot to internal networks, or brick the device.
Likely Case
Attackers gain shell access to execute commands, potentially stealing credentials, modifying device configuration, or using the router as a foothold for further attacks.
If Mitigated
Limited impact with proper network segmentation, firewall rules blocking management interfaces from untrusted networks, and regular monitoring.
🎯 Exploit Status
Exploitation requires access to the web management interface, which typically requires authentication. However, if default credentials are unchanged or other vulnerabilities exist, this could be chained for unauthenticated access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Tenda's official website for firmware updates. 2. Download the latest firmware for W20E. 3. Access router web interface. 4. Navigate to System Tools > Firmware Upgrade. 5. Upload and install the new firmware. 6. Reboot the router.
🔧 Temporary Workarounds
Restrict Web Management Access
allLimit access to the router's web management interface to trusted IP addresses only.
Change Default Credentials
allEnsure strong, unique credentials are set for the router administration interface.
🧯 If You Can't Patch
- Isolate the router on a dedicated VLAN with strict firewall rules preventing external access to management interfaces.
- Implement network monitoring and intrusion detection specifically for command injection patterns targeting the router's IP.
🔍 How to Verify
Check if Vulnerable:
Check firmware version via router web interface: System Status > Firmware Version. If version is V15.11.0.6, the device is vulnerable.Check Version:
curl -s http://router-ip/goform/getStatus | grep -i version (if API accessible)Verify Fix Applied:
After updating firmware, verify the version has changed from V15.11.0.6 to a newer version.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/setDebugCfg with suspicious level parameter values
- Commands like ';', '|', '&', or '`' in web interface logs
Network Indicators:
- Unexpected outbound connections from router to external IPs
- Unusual traffic patterns from router management interface
SIEM Query:
source="router_logs" AND (uri="/goform/setDebugCfg" AND (level="*;*" OR level="*|*" OR level="*&*" OR level="*`*"))