CVE-2021-45630
📋 TL;DR
This vulnerability allows unauthenticated remote attackers to execute arbitrary commands on affected NETGEAR WiFi systems. It affects multiple NETGEAR Orbi and Nighthawk models running outdated firmware versions. Attackers can exploit this without any credentials.
💻 Affected Systems
- NETGEAR CBR40
- NETGEAR CBR750
- NETGEAR RBK752
- NETGEAR RBR750
- NETGEAR RBS750
- NETGEAR RBK852
- NETGEAR RBR850
- NETGEAR RBS850
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network pivoting to internal systems, and data exfiltration.
Likely Case
Device takeover for botnet recruitment, DNS hijacking, credential theft from network traffic, and denial of service.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Exploitation requires no authentication and has been weaponized in real attacks. Public exploit code exists.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: CBR40: 2.5.0.24, CBR750: 4.6.3.6, RBK752/RBR750/RBS750: 3.2.17.12, RBK852/RBR850/RBS850: 3.2.17.12
Vendor Advisory: https://kb.netgear.com/000064135/Security-Advisory-for-Pre-Authentication-Command-Injection-on-Some-WiFi-Systems-PSV-2020-0498
Restart Required: Yes
Instructions:
1. Log into NETGEAR router admin interface. 2. Navigate to Advanced > Administration > Firmware Update. 3. Check for updates and apply the latest firmware. 4. Reboot the device after update completes.
🔧 Temporary Workarounds
Network Segmentation
allIsolate affected devices from critical internal networks and internet exposure
Firewall Rules
allBlock all inbound WAN access to router management interfaces
🧯 If You Can't Patch
- Disable remote management and WAN access to admin interface
- Replace affected devices with patched models or alternative vendors
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router admin interface under Advanced > Administration > Firmware UpdateCheck Version:
Login to router web interface and navigate to Advanced > Administration > Firmware UpdateVerify Fix Applied:
Confirm firmware version matches or exceeds patched versions listed in fix_official section📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Multiple failed authentication attempts followed by successful access
- Unexpected process creation
Network Indicators:
- Unusual outbound connections from router
- DNS queries to suspicious domains
- Unexpected port scans originating from router
SIEM Query:
source="router_logs" AND (command="*;*" OR command="*|*" OR command="*`*" OR command="*$(*")