CVE-2025-57528
📋 TL;DR
This vulnerability in Tenda AC6 routers allows attackers to cause denial of service through buffer overflow in the formSetCfm function. Attackers can crash the device by sending specially crafted requests to the SetCfm URI path. Users of affected Tenda AC6 router models are at risk.
💻 Affected Systems
- Tenda AC6
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device crash requiring physical power cycle, potentially leading to extended network downtime and service disruption.
Likely Case
Router becomes unresponsive, requiring reboot and causing temporary network outage for connected devices.
If Mitigated
With proper network segmentation and access controls, impact limited to isolated network segment.
🎯 Exploit Status
Public GitHub repository contains detailed exploitation information and proof-of-concept.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates
2. Download latest firmware for AC6 model
3. Access router admin interface
4. Navigate to firmware upgrade section
5. Upload and apply new firmware
6. Reboot router after update
🔧 Temporary Workarounds
Network Access Restriction
linuxRestrict access to router admin interface to trusted IP addresses only
iptables -A INPUT -p tcp --dport 80 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
Disable Remote Management
allTurn off remote administration features if not needed
🧯 If You Can't Patch
- Segment router management to isolated VLAN with strict access controls
- Implement network monitoring for unusual traffic patterns to SetCfm endpoint
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System Status or Firmware Upgrade sectionCheck Version:
curl -s http://router-ip/status.cgi | grep firmwareVerify Fix Applied:
Verify firmware version has been updated to a version later than US_AC6V1.0BR_V15.03.05.16_multi_TD01📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /SetCfm endpoint
- Router crash/reboot events in system logs
- Buffer overflow error messages
Network Indicators:
- Unusual HTTP POST requests to router IP on port 80 targeting /SetCfm
- Traffic containing funcname, funcpara1, funcpara2 parameters
SIEM Query:
source="router_logs" AND (uri_path="/SetCfm" OR message="*buffer overflow*")