CVE-2024-51257
📋 TL;DR
This vulnerability allows attackers to inject malicious commands into the mainfunction.cgi component of DrayTek Vigor3900 routers by exploiting the doCertificate function, leading to arbitrary command execution. Organizations using affected DrayTek Vigor3900 routers with vulnerable firmware versions are at risk.
💻 Affected Systems
- DrayTek Vigor3900
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the router allowing attackers to pivot to internal networks, intercept/modify traffic, install persistent backdoors, or use the device for further attacks.
Likely Case
Router compromise leading to network disruption, credential theft, or use as a foothold for internal network reconnaissance.
If Mitigated
Limited impact if network segmentation isolates the router and strict access controls prevent exploitation attempts.
🎯 Exploit Status
Exploitation requires access to the web interface. The GitHub reference contains technical details that could facilitate exploitation.
🛠️ 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. Apply any available patches immediately.
🔧 Temporary Workarounds
Restrict Web Interface Access
allLimit access to the router's web management interface to trusted IP addresses only.
Disable Unnecessary Services
allDisable remote management features if not required.
🧯 If You Can't Patch
- Isolate the router in a dedicated network segment with strict firewall rules
- Implement network monitoring for suspicious traffic to/from the router
🔍 How to Verify
Check if Vulnerable:
Check the router firmware version via the web interface or CLI. If version is 1.5.1.3, the device is vulnerable.Check Version:
Login to router web interface and check System Status > Firmware InformationVerify Fix Applied:
Verify firmware has been updated to a version later than 1.5.1.3.📡 Detection & Monitoring
Log Indicators:
- Unusual access to mainfunction.cgi
- Multiple failed login attempts followed by successful access
- Unexpected command execution in system logs
Network Indicators:
- Unusual outbound connections from the router
- Traffic patterns suggesting command and control activity
SIEM Query:
source="router_logs" AND (uri="*mainfunction.cgi*" OR message="*doCertificate*")