CVE-2024-50667
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on Trendnet TEW-820AP routers via stack overflow in the boa HTTP daemon when processing IPv6 configuration requests. Attackers can exploit insufficient IPv6 address validation in specific web form endpoints to gain full control of affected devices. All users of Trendnet TEW-820AP routers with vulnerable firmware versions are affected.
💻 Affected Systems
- Trendnet TEW-820AP
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, lateral movement to other devices, and botnet recruitment.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and IPv6 is disabled.
🎯 Exploit Status
Public GitHub repository contains vulnerability details and likely exploitation methods. CVSS 9.8 indicates trivial exploitation with high impact.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.trendnet.com/support/support-detail.asp?prod=100_TEW-820AP
Restart Required: Yes
Instructions:
1. Check Trendnet website for firmware updates. 2. Download latest firmware. 3. Access router admin interface. 4. Navigate to firmware update section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable IPv6 on router
allPrevent exploitation by disabling IPv6 functionality entirely
Access router admin interface -> Network -> IPv6 -> Disable
Restrict web interface access
allLimit admin interface access to trusted IP addresses only
Access router admin interface -> Security -> Access Control -> Restrict to specific IPs
🧯 If You Can't Patch
- Isolate affected routers in separate VLAN with strict firewall rules
- Implement network monitoring for exploitation attempts and block malicious IPs
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System Status or Firmware Update sectionCheck Version:
curl -s http://router-ip/ | grep -i firmware or check web interfaceVerify Fix Applied:
Verify firmware version is newer than 1.01.B01 and test IPv6 form endpoints with invalid input📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /boafrm/formIPv6Addr, /boafrm/formIpv6Setup, /boafrm/formDnsv6 with long parameters
- Router crash/restart logs
- Unusual process execution in system logs
Network Indicators:
- HTTP requests with abnormally long IPv6 address parameters
- Traffic patterns suggesting reverse shell connections from router
SIEM Query:
source="router_logs" AND (uri="/boafrm/formIPv6Addr" OR uri="/boafrm/formIpv6Setup" OR uri="/boafrm/formDnsv6") AND parameter_length>100