CVE-2025-11120
📋 TL;DR
A buffer overflow vulnerability in Tenda AC8 routers allows remote attackers to execute arbitrary code by exploiting the formSetServerConfig function. This affects Tenda AC8 routers running firmware version 16.03.34.06. Attackers can compromise the router remotely without authentication.
💻 Affected Systems
- Tenda AC8
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router compromise leading to persistent backdoor installation, network traffic interception, and lateral movement to connected devices.
Likely Case
Router takeover enabling DNS hijacking, credential theft, and botnet recruitment.
If Mitigated
Limited impact if router is behind firewall with restricted WAN access and regular firmware updates.
🎯 Exploit Status
Public exploit code exists on GitHub, making exploitation accessible even to less skilled attackers.
🛠️ 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. Upload and install new firmware 5. Reboot router
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router administration interface
Network Segmentation
allIsolate router management interface to separate VLAN
🧯 If You Can't Patch
- Replace affected routers with different models or brands
- Implement strict firewall rules blocking all WAN access to router management ports
🔍 How to Verify
Check if Vulnerable:
Access router admin interface and check firmware version matches 16.03.34.06Check Version:
Check router web interface or use nmap/router scanning toolsVerify Fix Applied:
Verify firmware version has been updated to a version later than 16.03.34.06📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/SetServerConfig
- Router reboot events
- Configuration changes
Network Indicators:
- Exploit traffic patterns to router management interface
- Unusual outbound connections from router
SIEM Query:
source="router_logs" AND (uri="/goform/SetServerConfig" OR event="buffer_overflow")