CVE-2021-45626
📋 TL;DR
This vulnerability allows unauthenticated attackers to execute arbitrary commands on affected NETGEAR WiFi systems. It affects multiple NETGEAR Orbi mesh WiFi router models before specific firmware versions. Attackers can exploit this without any credentials.
💻 Affected Systems
- NETGEAR RBK20
- NETGEAR RBR20
- NETGEAR RBS20
- NETGEAR RBK40
- NETGEAR RBR40
- NETGEAR RBS40
- NETGEAR RBK50
- NETGEAR RBR50
- NETGEAR RBS50
- NETGEAR RBS50Y
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing installation of persistent malware, network traffic interception, lateral movement to connected devices, and creation of botnet nodes.
Likely Case
Remote code execution leading to device takeover, credential theft, DNS hijacking, and network surveillance.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and not internet-facing.
🎯 Exploit Status
Public exploit code available. Simple HTTP request with crafted parameters triggers command injection.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: RBK20/RBR20: 2.6.1.36+, RBS20: 2.6.1.38+, RBK40/RBR40: 2.6.1.36+, RBS40: 2.6.1.38+, RBK50/RBR50/RBS50/RBS50Y: 2.6.1.40+
Vendor Advisory: https://kb.netgear.com/000064068/Security-Advisory-for-Pre-Authentication-Command-Injection-on-Some-WiFi-Systems-PSV-2019-0152
Restart Required: Yes
Instructions:
1. Log into router web interface. 2. Navigate to Advanced > Administration > Firmware Update. 3. Check for updates. 4. If update available, download and install. 5. Router will reboot automatically.
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to web management interface
Navigate to Advanced > Administration > Remote Management and disable
Network segmentation
allPlace devices on isolated VLAN with strict firewall rules
🧯 If You Can't Patch
- Immediately disconnect from internet if possible
- Implement strict firewall rules blocking all inbound traffic to device management ports (80, 443, 8080)
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface under Advanced > Administration > Firmware UpdateCheck Version:
curl -s http://router-ip/currentsetting.htm | grep firmwareVerify Fix Applied:
Verify firmware version matches or exceeds patched versions listed above📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests to management interface with shell metacharacters
- Unexpected process execution in system logs
- Failed authentication attempts followed by successful command execution
Network Indicators:
- HTTP requests containing shell commands (;, |, &, $, etc.) to router management ports
- Outbound connections from router to unusual destinations
SIEM Query:
source="router-logs" AND (http_uri="*;*" OR http_uri="*|*" OR http_uri="*&*" OR http_uri="*$(*")