CVE-2024-51138
📋 TL;DR
A critical stack-based buffer overflow vulnerability in DrayTek router TR069 STUN server URL parsing allows remote attackers to execute arbitrary code with elevated privileges. This affects multiple DrayTek Vigor router models running vulnerable firmware versions. Attackers can exploit this without authentication to gain complete control of affected devices.
💻 Affected Systems
- Vigor165
- Vigor166
- Vigor2620
- LTE200
- Vigor2860
- Vigor2925
- Vigor2862
- Vigor2926
- Vigor2133
- Vigor2762
- Vigor2832
- Vigor2135
- Vigor2765
- Vigor2766
- Vigor2865
- Vigor2866
- Vigor2927
- Vigor2962
- Vigor3912
- Vigor3910
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to network infiltration, data exfiltration, ransomware deployment, and persistent backdoor installation across the entire network.
Likely Case
Router takeover enabling man-in-the-middle attacks, credential theft, network traffic interception, and lateral movement to connected systems.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering, though internal threats remain possible.
🎯 Exploit Status
CVSS 9.8 indicates trivial exploitation with high impact. No authentication required. Technical details are public in advisory.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check DrayTek website for specific model updates
Vendor Advisory: http://draytek.com
Restart Required: Yes
Instructions:
1. Visit DrayTek support portal. 2. Download latest firmware for your specific model. 3. Backup router configuration. 4. Upload firmware via web interface. 5. Reboot router. 6. Verify firmware version updated.
🔧 Temporary Workarounds
Disable TR069 STUN Server
allTurn off vulnerable TR069 STUN service to prevent exploitation
Restrict WAN Access
allBlock inbound TR069 ports (typically 7547, 34567) at firewall
🧯 If You Can't Patch
- Isolate affected routers in separate VLAN with strict access controls
- Implement network segmentation to limit lateral movement if compromised
🔍 How to Verify
Check if Vulnerable:
Check router web interface for model and firmware version, compare against affected versions listCheck Version:
Login to router web interface and navigate to System Maintenance > Firmware InformationVerify Fix Applied:
Confirm firmware version is above vulnerable threshold for your specific model📡 Detection & Monitoring
Log Indicators:
- Unusual TR069 connection attempts
- Multiple malformed URL parameter requests
- Unexpected router reboots or configuration changes
Network Indicators:
- Excessive traffic to TR069 ports (7547, 34567)
- Suspicious outbound connections from router
SIEM Query:
source_ip=router_ip AND (dest_port=7547 OR dest_port=34567) AND url_length>threshold