CVE-2025-50611
📋 TL;DR
A buffer overflow vulnerability in Netis WF2880 routers allows attackers to cause denial of service by sending specially crafted payloads to the cgitest.cgi endpoint. This affects users of Netis WF2880 routers running vulnerable firmware versions. The vulnerability requires network access to the router's web interface.
💻 Affected Systems
- Netis WF2880
📦 What is this software?
Wf2880 Firmware by Netis Systems
⚠️ Risk & Real-World Impact
Worst Case
Complete router crash requiring physical reboot, potential for remote code execution if buffer overflow can be leveraged for arbitrary code execution.
Likely Case
Router becomes unresponsive, requiring reboot to restore functionality, causing temporary network disruption.
If Mitigated
Limited impact if router is behind firewall with restricted access to web interface.
🎯 Exploit Status
Proof of concept available on GitHub shows simple HTTP POST exploitation. No authentication required to trigger vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Netis website for firmware updates
2. Download latest firmware for WF2880
3. Access router web interface
4. Navigate to firmware upgrade section
5. Upload and apply new firmware
6. Reboot router after update
🔧 Temporary Workarounds
Disable web interface access
linuxRestrict access to router web management interface
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
Block cgitest.cgi access
allUse web server rules to block access to vulnerable endpoint
LocationMatch "^/cgitest\.cgi"
Order deny,allow
Deny from all
🧯 If You Can't Patch
- Place router behind firewall with strict inbound rules blocking web interface ports (80, 443, 8080)
- Change default router management IP to non-standard subnet and restrict access to management VLAN only
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface or SSH: cat /proc/version or check web admin panel system infoCheck Version:
curl -s http://router-ip/cgi-bin/cgitest.cgi | grep version || echo 'Check web interface'Verify Fix Applied:
Verify firmware version is newer than v2.1.40207 and test cgitest.cgi endpoint with safe payload📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /cgi-bin/cgitest.cgi
- Router crash/reboot logs
- Unusual payloads containing wl_sec_set_5g or wl_sec_rp_set_5g parameters
Network Indicators:
- HTTP POST requests to router IP on port 80/443 with large payloads to cgitest.cgi
- Sudden loss of router connectivity
SIEM Query:
source="router_logs" AND (uri="/cgi-bin/cgitest.cgi" OR (method="POST" AND uri CONTAINS "cgitest"))