CVE-2025-25504
📋 TL;DR
This vulnerability allows unauthenticated attackers with network access to connect to TCP port 4444 on affected Gefen WebFWC devices and execute arbitrary commands with root privileges. It affects Gefen AV over IP products running specific vulnerable versions. Attackers can fully compromise the device without any credentials.
💻 Affected Systems
- Gefen WebFWC (AV over IP products)
📦 What is this software?
Gefen Webfwc by Niceforyou
Gefen Webfwc by Niceforyou
Gefen Webfwc by Niceforyou
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover, data exfiltration, lateral movement to other network systems, installation of persistent backdoors, and disruption of AV operations.
Likely Case
Remote code execution leading to device compromise, credential theft, and potential use as a foothold for further network attacks.
If Mitigated
Limited to internal network access only, with proper network segmentation preventing external exploitation.
🎯 Exploit Status
Simple network connection to port 4444 allows command execution. Public details available in the referenced advisory.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: http://gefen.com
Restart Required: No
Instructions:
Check Gefen website for security updates. If no patch, implement workarounds immediately.
🔧 Temporary Workarounds
Block TCP port 4444
linuxUse firewall rules to block inbound connections to port 4444 on affected devices.
iptables -A INPUT -p tcp --dport 4444 -j DROP
iptables -A INPUT -p tcp --dport 4444 -s 0.0.0.0/0 -j DROP
Disable jncs.sh service
linuxStop and disable the vulnerable service if not required for functionality.
systemctl stop jncs
systemctl disable jncs
kill $(pgrep -f jncs.sh)
🧯 If You Can't Patch
- Segment affected devices in isolated network zones with strict access controls.
- Implement network monitoring and intrusion detection for port 4444 connections.
🔍 How to Verify
Check if Vulnerable:
Check if TCP port 4444 is listening: 'netstat -tlnp | grep 4444' or 'ss -tlnp | grep 4444'. If listening, check version: 'cat /etc/version' or similar.Check Version:
Check device firmware version via web interface or 'cat /etc/version' on device shell.Verify Fix Applied:
Verify port 4444 is no longer accessible: 'nc -zv [device_ip] 4444' should fail. Check service status: 'systemctl status jncs' should show inactive.📡 Detection & Monitoring
Log Indicators:
- Unexpected connections to port 4444 in firewall logs
- jncs.sh process spawning unusual child processes
Network Indicators:
- TCP connections to port 4444 from unauthorized sources
- Unusual outbound traffic from device after port 4444 connection
SIEM Query:
source_port=4444 OR dest_port=4444 | stats count by src_ip, dest_ip