CVE-2024-39760
📋 TL;DR
This critical vulnerability allows unauthenticated attackers to execute arbitrary operating system commands on Wavlink AC3000 routers by sending specially crafted HTTP requests to the login.cgi endpoint. Attackers can gain full control of affected devices, potentially compromising entire networks. All users of vulnerable Wavlink AC3000 routers are affected.
💻 Affected Systems
- Wavlink AC3000
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover leading to persistent backdoor installation, network traffic interception, lateral movement to other devices, and use as botnet nodes for DDoS attacks or cryptocurrency mining.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept network traffic, steal credentials, and pivot to attack other devices on the network.
If Mitigated
Limited impact if device is behind strict firewall rules, not internet-facing, and network segmentation prevents lateral movement.
🎯 Exploit Status
The vulnerability is well-documented in public advisories with technical details that make exploitation straightforward. The CVSS 10.0 score indicates trivial exploitation with maximum impact.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No vendor advisory found at time of analysis
Restart Required: No
Instructions:
1. Check Wavlink website for firmware updates. 2. If update available, download and install via web interface. 3. Monitor vendor communications for security patches.
🔧 Temporary Workarounds
Network Isolation
linuxPrevent external access to router web interface
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
Disable Web Interface
linuxTurn off vulnerable CGI functionality if possible
chmod 000 /www/cgi-bin/login.cgi
🧯 If You Can't Patch
- Immediately disconnect affected routers from the internet and place behind strict firewalls
- Implement network segmentation to isolate router management interfaces from user networks
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface at 192.168.10.1 or using command: cat /proc/version | grep M33A8Check Version:
curl -s http://192.168.10.1/ | grep -i firmware || ssh admin@router 'cat /proc/version'Verify Fix Applied:
Verify firmware version has been updated beyond M33A8.V5030.210505📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /cgi-bin/login.cgi
- Commands containing shell metacharacters in HTTP parameters
- Multiple failed login attempts followed by successful command execution
Network Indicators:
- HTTP requests to login.cgi with suspicious parameters like 'restart_min_value' containing shell commands
- Outbound connections from router to unknown IPs
SIEM Query:
source="router_logs" AND (url="/cgi-bin/login.cgi" AND (param="restart_min_value" OR param CONTAINS ";" OR param CONTAINS "|" OR param CONTAINS "`"))