CVE-2024-51244
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary commands on Draytek Vigor3900 routers by injecting malicious commands into the mainfunction.cgi component. Attackers can exploit this through the doIPSec function, leading to potential complete system compromise. Organizations using affected Draytek Vigor3900 routers are at risk.
💻 Affected Systems
- Draytek Vigor3900
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system takeover, data exfiltration, lateral movement to internal networks, and persistent backdoor installation.
Likely Case
Unauthorized command execution leading to network reconnaissance, credential harvesting, and potential ransomware deployment.
If Mitigated
Limited impact if network segmentation, strict firewall rules, and proper access controls prevent exploitation.
🎯 Exploit Status
The GitHub reference contains technical details that could facilitate exploitation. The vulnerability requires no authentication and has straightforward exploitation vectors.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Unknown
Restart Required: No
Instructions:
Check Draytek's official website for security advisories and firmware updates. If available, download the latest firmware and follow vendor instructions for updating.
🔧 Temporary Workarounds
Network Segmentation
allIsolate Vigor3900 devices from untrusted networks and restrict access to management interfaces.
Firewall Rules
allImplement strict firewall rules to block external access to the web management interface (typically port 80/443).
🧯 If You Can't Patch
- Implement network-based intrusion detection/prevention systems to monitor for exploitation attempts
- Disable unnecessary services and restrict administrative access to trusted IP addresses only
🔍 How to Verify
Check if Vulnerable:
Check the firmware version via the web interface (System Maintenance > Firmware Information) or SSH/Telnet console.Check Version:
ssh admin@router_ip 'show version' or check via web interface at System Maintenance > Firmware InformationVerify Fix Applied:
Verify firmware version has been updated to a version later than 1.5.1.3 through the web interface or console.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Multiple failed authentication attempts followed by successful access
- Suspicious CGI requests to mainfunction.cgi
Network Indicators:
- Unusual outbound connections from the router
- Traffic patterns indicating command and control communication
- HTTP requests with command injection payloads
SIEM Query:
source="vigor3900" AND (uri="*mainfunction.cgi*" AND (method="POST" OR method="GET") AND (content="*doIPSec*" OR content="*|*" OR content="*;*" OR content="*`*"))