CVE-2025-4120
📋 TL;DR
A critical buffer overflow vulnerability in Netgear JWNR2000v2 routers allows remote attackers to execute arbitrary code by manipulating the 'host' argument in the sub_4238E8 function. This affects JWNR2000v2 routers running firmware version 1.0.0.11. The vulnerability is remotely exploitable without authentication.
💻 Affected Systems
- Netgear JWNR2000v2
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, network infiltration, and persistent backdoor installation.
Likely Case
Remote code execution allowing attackers to intercept network traffic, modify router settings, or launch attacks against internal devices.
If Mitigated
Limited impact if device is behind firewall with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public exploit details available on GitHub/vuldb. Remote exploitation without authentication makes weaponization likely.
🛠️ 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. If update available, download and install via router admin interface. 3. Reboot router after update. Note: Vendor has not responded to disclosure.
🔧 Temporary Workarounds
Network Isolation
allPlace router behind firewall with strict inbound filtering to block external exploitation attempts.
Access Restriction
allConfigure firewall rules to restrict access to router management interface to trusted IPs only.
🧯 If You Can't Patch
- Replace affected router with supported model that receives security updates
- Implement network segmentation to isolate router from critical systems
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface (typically 192.168.1.1 or 192.168.0.1) under Advanced > Administration > Firmware Update.Check Version:
No CLI command - check via web interface at router IP addressVerify Fix Applied:
Verify firmware version is no longer 1.0.0.11. Check Netgear support for any security updates.📡 Detection & Monitoring
Log Indicators:
- Unusual traffic to router management interface
- Multiple failed exploitation attempts
- Unexpected configuration changes
Network Indicators:
- Unusual outbound connections from router
- Traffic patterns suggesting router compromise
SIEM Query:
source_ip=router_ip AND (http_user_agent CONTAINS "exploit" OR http_uri CONTAINS "sub_4238E8")