CVE-2020-26907
📋 TL;DR
This vulnerability allows unauthenticated attackers to execute arbitrary commands on affected NETGEAR WiFi systems. It affects RBK852, RBR850, and RBS850 devices running firmware versions before 3.2.16.6. Attackers can exploit this without any credentials.
💻 Affected Systems
- 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 traffic interception, lateral movement to other devices, and potential data exfiltration.
Likely Case
Remote code execution allowing attackers to modify device settings, disrupt network connectivity, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Command injection vulnerabilities are typically easy to exploit once details are known. The advisory confirms pre-authentication exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.2.16.6 or later
Vendor Advisory: https://kb.netgear.com/000062347/Security-Advisory-for-Pre-Authentication-Command-Injection-on-Some-WiFi-Systems-PSV-2020-0264
Restart Required: Yes
Instructions:
1. Log into NETGEAR router admin interface. 2. Navigate to Advanced > Administration > Firmware Update. 3. Check for updates and install version 3.2.16.6 or later. 4. Reboot the device after installation.
🔧 Temporary Workarounds
Network Segmentation
allPlace affected devices behind firewalls with strict inbound filtering to block external exploitation attempts.
Access Control Lists
allImplement network ACLs to restrict access to device management interfaces from trusted IPs only.
🧯 If You Can't Patch
- Isolate affected devices in a separate VLAN with no internet access
- Implement strict firewall rules to block all inbound traffic to device management interfaces
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router admin interface under Advanced > Administration > Firmware Update. If version is below 3.2.16.6, device is vulnerable.Check Version:
Check via web interface or use 'curl http://router-ip/currentsetting.htm' (exact endpoint may vary)Verify Fix Applied:
Confirm firmware version is 3.2.16.6 or higher in the admin interface after update.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Multiple failed authentication attempts followed by successful access
- Unexpected configuration changes
Network Indicators:
- Unusual outbound connections from router
- Traffic to known malicious IPs from router
- Port scanning originating from router
SIEM Query:
source="router_logs" AND (command="*;*" OR command="*|*" OR command="*`*" OR command="*$(*")