CVE-2021-45628
📋 TL;DR
This vulnerability allows unauthenticated attackers to execute arbitrary commands on affected NETGEAR WiFi systems through command injection. It affects multiple NETGEAR router and mesh WiFi system models running vulnerable firmware versions. Attackers can exploit this without any authentication.
💻 Affected Systems
- NETGEAR CBR40
- CBR750
- RBK752
- RBR750
- RBS750
- RBK852
- RBR850
- RBS850
- RBS40V
- RBW30
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attackers to install persistent malware, intercept all network traffic, pivot to internal networks, and use the device as a botnet node.
Likely Case
Device takeover leading to network surveillance, credential theft, DNS hijacking, and lateral movement to connected devices.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Exploitation is straightforward with public proof-of-concept code available. No authentication required.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: CBR40: 2.5.0.24+, CBR750: 3.2.18.2+, RBK752/RBR750/RBS750/RBK852/RBR850/RBS850: 3.2.17.12+, RBS40V: 2.6.2.4+, RBW30: 2.6.2.2+
Vendor Advisory: https://kb.netgear.com/000064125/Security-Advisory-for-Pre-Authentication-Command-Injection-on-Some-WiFi-Systems-PSV-2020-0472
Restart Required: Yes
Instructions:
1. Log into router admin interface. 2. Navigate to Advanced > Administration > Firmware Update. 3. Check for updates and apply latest firmware. 4. Reboot device after update completes.
🔧 Temporary Workarounds
Network Isolation
allPlace affected devices behind firewalls with strict inbound filtering to block external exploitation attempts.
Disable Remote Management
allDisable WAN-side administration access to prevent external attackers from reaching vulnerable interfaces.
🧯 If You Can't Patch
- Replace affected devices with patched models or alternative vendors
- Implement strict network segmentation to isolate vulnerable devices from critical assets
🔍 How to Verify
Check if Vulnerable:
Check current firmware version via router admin interface at Advanced > Administration > Firmware UpdateCheck Version:
Login to router web interface and navigate to Advanced > Administration > Firmware Update to view current versionVerify Fix Applied:
Verify firmware version matches or exceeds patched versions listed in vendor advisory📡 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 SSH/Telnet connections from router
SIEM Query:
source="router_logs" AND (command="*;*" OR command="*|*" OR command="*`*" OR command="*$(*")