CVE-2025-10963
📋 TL;DR
This CVE describes a command injection vulnerability in Wavlink NU516U1 routers running firmware version M16U1_V240425. Attackers can remotely execute arbitrary commands by manipulating the 'del_flag' parameter in the firewall.cgi endpoint. This affects all users of this specific router model with the vulnerable firmware.
💻 Affected Systems
- Wavlink NU516U1 router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attackers to install persistent backdoors, steal credentials, pivot to internal networks, or use the device for botnet activities.
Likely Case
Unauthorized command execution leading to device configuration changes, network disruption, or credential harvesting from the router.
If Mitigated
Limited impact with proper network segmentation and firewall rules preventing external access to the vulnerable endpoint.
🎯 Exploit Status
Proof of concept available on GitHub; exploitation requires network access to the router's web interface but no authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: No
Instructions:
No official patch available. Monitor Wavlink website for firmware updates addressing CVE-2025-10963.
🔧 Temporary Workarounds
Block CGI endpoint access
linuxUse firewall rules to block external access to /cgi-bin/firewall.cgi endpoint
iptables -A INPUT -p tcp --dport 80 -m string --string "/cgi-bin/firewall.cgi" --algo bm -j DROP
iptables -A INPUT -p tcp --dport 443 -m string --string "/cgi-bin/firewall.cgi" --algo bm -j DROP
Disable remote administration
allTurn off remote management/administration features on the router
🧯 If You Can't Patch
- Replace affected devices with non-vulnerable models
- Implement strict network segmentation to isolate vulnerable routers
🔍 How to Verify
Check if Vulnerable:
Check router web interface for firmware version M16U1_V240425 or attempt exploitation using published PoCCheck Version:
Check router web interface under System Status or Administration settingsVerify Fix Applied:
Verify firmware version has been updated to a version later than M16U1_V240425📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /cgi-bin/firewall.cgi with shell metacharacters in parameters
- Unexpected command execution in system logs
Network Indicators:
- Suspicious traffic patterns from router to external IPs
- Unexpected outbound connections from router
SIEM Query:
source="router_logs" AND uri="/cgi-bin/firewall.cgi" AND (param="del_flag" AND value MATCHES "[;&|`$()]+")