CVE-2025-61128
📋 TL;DR
A stack-based buffer overflow vulnerability in WAVLINK router firmware allows attackers to execute arbitrary code by sending a specially crafted HTTP POST request to login.cgi. This affects WAVLINK QUANTUM D3G/WL-WN530HG3 routers with firmware M30HG3_V240730 and potentially other models. Attackers can gain full control of affected devices without authentication.
💻 Affected Systems
- WAVLINK QUANTUM D3G
- WAVLINK WL-WN530HG3
- Potentially other WAVLINK router models
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, lateral movement to internal networks, and botnet recruitment.
Likely Case
Remote code execution allowing attackers to modify device settings, intercept traffic, or use the device as a pivot point for further attacks.
If Mitigated
Limited to denial of service if exploit fails or device crashes, but successful exploitation typically leads to full compromise.
🎯 Exploit Status
Public proof-of-concept available in GitHub gist. Exploit requires sending a single HTTP POST request with crafted referrer header.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None known
Restart Required: Yes
Instructions:
1. Check WAVLINK website for firmware updates. 2. Download latest firmware for your model. 3. Access router web interface. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable Web Management Interface
allDisable the vulnerable web interface if remote management is not required.
Access router settings -> Administration -> Remote Management -> Disable
Restrict Web Interface Access
allLimit web interface access to specific IP addresses or internal network only.
Access router settings -> Firewall -> Access Control -> Add rules to restrict web interface
🧯 If You Can't Patch
- Isolate affected routers in separate VLAN with strict firewall rules
- Implement network monitoring for exploit attempts and block malicious IPs
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface under System Status or About page. If version is M30HG3_V240730 or earlier, assume vulnerable.Check Version:
curl -s http://router-ip/ | grep -i firmware || ssh admin@router-ip 'cat /etc/version'Verify Fix Applied:
Verify firmware version has been updated to a version newer than M30HG3_V240730. Test by attempting to access login.cgi with normal requests.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /login.cgi with unusually long referrer headers
- Multiple failed login attempts followed by successful exploit patterns
- System logs showing process crashes or memory errors
Network Indicators:
- HTTP traffic to router IP on port 80/443 with POST to /login.cgi and large referrer headers
- Outbound connections from router to unknown IPs after exploitation
SIEM Query:
source="router_logs" AND (url="/login.cgi" AND method="POST" AND referrer_length>500) OR (process="httpd" AND event="crash")