CVE-2025-4142
📋 TL;DR
A critical buffer overflow vulnerability in Netgear EX6200 wireless extenders allows remote attackers to execute arbitrary code by manipulating the 'host' argument in the sub_3C8EC function. This affects users running firmware version 1.0.3.94. The vulnerability is remotely exploitable without authentication.
💻 Affected Systems
- Netgear EX6200
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, network infiltration, and potential lateral movement to connected devices.
Likely Case
Device takeover enabling attackers to intercept network traffic, deploy malware, or create persistent backdoors.
If Mitigated
Limited impact if device is isolated behind firewalls with strict network segmentation and intrusion prevention systems.
🎯 Exploit Status
Public exploit details available in GitHub repository. Buffer overflow vulnerabilities in network devices are commonly weaponized.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.netgear.com/
Restart Required: Yes
Instructions:
1. Check Netgear support site for firmware updates. 2. Download latest firmware. 3. Access device web interface. 4. Navigate to firmware update section. 5. Upload and apply new firmware. 6. Reboot device.
🔧 Temporary Workarounds
Network Isolation
allIsolate EX6200 devices from internet and critical internal networks
Access Control
linuxRestrict administrative access to trusted IP addresses only
iptables -A INPUT -p tcp --dport 80 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Replace vulnerable devices with supported models
- Implement strict network segmentation and monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Access device web interface > Advanced > Administration > Firmware Update to check current versionCheck Version:
curl -s http://device-ip/currentsetting.htm | grep FirmwareVerify Fix Applied:
Verify firmware version is newer than 1.0.3.94 after update📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests to device management interface
- Multiple failed buffer overflow attempts in logs
Network Indicators:
- Unusual traffic patterns to EX6200 management ports
- Suspicious payloads in HTTP requests
SIEM Query:
source="firewall.log" AND (dst_ip="EX6200_IP" AND dst_port=80) AND (http_uri CONTAINS "gui_Wireless_Security_state" OR http_payload_size>normal_threshold)