CVE-2025-25343
📋 TL;DR
CVE-2025-25343 is a critical buffer overflow vulnerability in Tenda AC6 router firmware that allows remote code execution. Attackers can exploit this vulnerability to take complete control of affected routers. This affects all users running vulnerable firmware versions of Tenda AC6 routers.
💻 Affected Systems
- Tenda AC6 wireless router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router compromise leading to persistent backdoor installation, credential theft, network traffic interception, and pivot point for attacking internal network devices.
Likely Case
Router takeover allowing DNS hijacking, credential harvesting, and botnet recruitment for DDoS attacks.
If Mitigated
Limited impact if routers are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public GitHub repository contains proof-of-concept exploit code. The vulnerability is in formexeCommand function which handles web interface commands.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Unknown
Restart Required: Yes
Instructions:
1. Check Tenda official website for firmware updates. 2. Download latest firmware for AC6 model. 3. Access router admin interface. 4. Navigate to System Tools > Firmware Upgrade. 5. Upload and install new firmware. 6. Reboot router after installation.
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to router web interface
Implement network segmentation
allIsolate router management interface from user networks
🧯 If You Can't Patch
- Replace affected routers with different models from vendors with better security track record
- Place routers behind dedicated firewalls with strict inbound filtering rules
🔍 How to Verify
Check if Vulnerable:
Access router web interface > System Status > Firmware Version. Check if version matches V15.03.05.16.Check Version:
curl -s http://router-ip/goform/GetSysInfo | grep -i versionVerify Fix Applied:
After firmware update, verify version is higher than V15.03.05.16 in System Status page.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/formexeCommand
- Multiple failed authentication attempts followed by successful command execution
- Router reboot events without user action
Network Indicators:
- Unusual outbound connections from router to unknown IPs
- DNS queries to suspicious domains from router itself
- Port scanning originating from router
SIEM Query:
source="router_logs" AND (uri="/goform/formexeCommand" OR command="formexeCommand")