CVE-2025-50609
📋 TL;DR
A buffer overflow vulnerability in Netis WF2880 routers allows attackers to crash the device by sending specially crafted requests to the cgitest.cgi endpoint. This causes a Denial of Service (DoS) condition, potentially disrupting network connectivity. Organizations using Netis WF2880 routers with vulnerable firmware are affected.
💻 Affected Systems
- Netis WF2880
📦 What is this software?
Wf2880 Firmware by Netis Systems
⚠️ Risk & Real-World Impact
Worst Case
Complete device crash requiring physical reboot, extended network downtime, and potential for remote code execution if the buffer overflow can be weaponized beyond DoS.
Likely Case
Router becomes unresponsive, requiring manual reboot to restore functionality, causing temporary network disruption.
If Mitigated
Limited impact if the router is behind a firewall with restricted access to management interfaces.
🎯 Exploit Status
The GitHub repository contains proof-of-concept code demonstrating the vulnerability. The exploit appears straightforward, requiring only HTTP requests to the vulnerable endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Unknown
Restart Required: No
Instructions:
No official patch is currently available. Monitor Netis vendor communications for security updates.
🔧 Temporary Workarounds
Disable cgitest.cgi endpoint
linuxRemove or restrict access to the vulnerable cgitest.cgi file to prevent exploitation.
ssh admin@router-ip
rm /www/cgi-bin/cgitest.cgi
Or modify web server configuration to block access to cgitest.cgi
Restrict web interface access
linuxConfigure firewall rules to limit access to the router's web management interface to trusted IP addresses only.
iptables -A INPUT -p tcp --dport 80 -s trusted-ip-range -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Isolate vulnerable routers in a separate network segment with strict access controls
- Implement network monitoring to detect exploitation attempts targeting the cgitest.cgi endpoint
🔍 How to Verify
Check if Vulnerable:
Check if the router responds to requests to /cgi-bin/cgitest.cgi with specify_parame parameter. Use curl: curl -v 'http://router-ip/cgi-bin/cgitest.cgi?specify_parame=test'Check Version:
Check web interface at http://router-ip or login via SSH and check firmware version in system informationVerify Fix Applied:
Verify that cgitest.cgi is no longer accessible or that requests no longer cause crashes. Test with the same curl command after implementing workarounds.📡 Detection & Monitoring
Log Indicators:
- Multiple requests to /cgi-bin/cgitest.cgi with long specify_parame values
- Router crash/reboot events in system logs
- Web server error logs showing buffer overflow errors
Network Indicators:
- HTTP requests to router IP on port 80/tcp with cgitest.cgi in URL and long parameter values
- Sudden drop in network traffic from router
SIEM Query:
source="router-logs" AND (url="*cgitest.cgi*" OR message="*buffer overflow*" OR message="*crash*")