CVE-2025-69763
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on Tenda AX3 routers by exploiting a stack overflow in the formSetIptv function via the vlanId parameter. Attackers can achieve full system compromise, potentially taking complete control of affected devices. All users running the vulnerable firmware version are affected.
💻 Affected Systems
- Tenda AX3 router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover enabling persistent backdoor installation, network traffic interception, lateral movement to other devices, and participation in botnets.
Likely Case
Remote code execution leading to device compromise, credential theft, DNS hijacking, and use as pivot point for internal network attacks.
If Mitigated
Limited impact if devices are behind firewalls with strict ingress filtering and network segmentation, though internal threats remain.
🎯 Exploit Status
The vulnerability is in a web interface function and appears to be remotely exploitable without authentication based on the CWE-121 classification and CVSS score.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None provided in references
Restart Required: Yes
Instructions:
1. Check Tenda official website for firmware updates. 2. If update available, download from official source. 3. Log into router admin interface. 4. Navigate to firmware upgrade section. 5. Upload new firmware file. 6. Wait for upgrade to complete. 7. Verify new firmware version.
🔧 Temporary Workarounds
Disable remote management
allDisable web management interface on WAN/Internet-facing interface
Network segmentation
allPlace router in isolated network segment with strict firewall rules
🧯 If You Can't Patch
- Isolate affected devices from critical networks using VLANs or physical segmentation
- Implement strict firewall rules to block all unnecessary inbound traffic to router management interfaces
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface under System Status or Firmware Upgrade sectionCheck Version:
Check via web interface or SSH if enabled: cat /proc/version or similar firmware version fileVerify Fix Applied:
Verify firmware version is no longer v16.03.12.11 after update📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to formSetIptv endpoint
- Large vlanId parameter values in HTTP logs
- Crash logs or core dumps from router processes
Network Indicators:
- Exploit traffic patterns to router management interface
- Unusual outbound connections from router after compromise
SIEM Query:
source="router_logs" AND (uri="/goform/setIptv" OR uri="/goform/formSetIptv") AND (param="vlanId" AND length(value)>100)