CVE-2024-39757
📋 TL;DR
This vulnerability allows authenticated attackers to execute arbitrary commands on Wavlink AC3000 routers by exploiting a stack-based buffer overflow in the wireless.cgi AddMac() function. Attackers can achieve remote code execution with router administrator privileges. Only users of specific Wavlink router models running vulnerable firmware are affected.
💻 Affected Systems
- Wavlink AC3000
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the router allowing attackers to intercept all network traffic, install persistent malware, pivot to internal networks, and use the device for botnet activities.
Likely Case
Router takeover leading to credential theft, DNS hijacking, man-in-the-middle attacks, and lateral movement to connected devices.
If Mitigated
Limited impact if network segmentation isolates the router and strong authentication prevents unauthorized access.
🎯 Exploit Status
Requires authentication but default credentials may be used. Buffer overflow leads to command execution.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Wavlink website for firmware updates
2. Download latest firmware for AC3000
3. Log into router admin interface
4. Navigate to firmware update section
5. Upload and apply new firmware
6. Reboot router after update
🔧 Temporary Workarounds
Disable Remote Administration
allPrevent external access to router admin interface
Change Default Credentials
allUse strong unique passwords for router admin access
🧯 If You Can't Patch
- Isolate router on separate VLAN with strict firewall rules
- Implement network monitoring for suspicious HTTP requests to wireless.cgi
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System Status or Firmware Update sectionCheck Version:
Not applicable - check via web interfaceVerify Fix Applied:
Verify firmware version is newer than M33A8.V5030.210505📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /cgi-bin/wireless.cgi with AddMac parameter containing unusually long strings
- Failed authentication attempts followed by successful login
Network Indicators:
- Unusual outbound connections from router
- DNS queries to suspicious domains from router
SIEM Query:
source="router_logs" AND (uri="/cgi-bin/wireless.cgi" AND method="POST" AND param="AddMac" AND length(param_value)>100)