CVE-2021-45541
📋 TL;DR
This vulnerability allows authenticated users to execute arbitrary commands on affected NETGEAR routers and WiFi systems through command injection. Attackers with valid credentials can gain elevated privileges and potentially take full control of the device. The vulnerability affects multiple NETGEAR router models running outdated firmware versions.
💻 Affected Systems
- NETGEAR R7900
- R7900P
- R8000
- R8000P
- RAX200
- MR60
- RAX45
- RAX80
- MS60
- RAX50
- RAX75
- RBR750
- RBR850
- RBS750
- RBS850
- RBK752
- RBK852
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the router allowing attackers to intercept all network traffic, install persistent malware, pivot to internal networks, and use the device as part of a botnet.
Likely Case
Local network compromise where an attacker with network access gains router control, enabling traffic monitoring, DNS hijacking, and credential theft from connected devices.
If Mitigated
Limited impact if strong authentication is enforced, network segmentation isolates the router, and regular monitoring detects unusual activity.
🎯 Exploit Status
Exploitation requires authentication but is straightforward once credentials are obtained. Public exploit code exists for similar NETGEAR vulnerabilities.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Varies by model - see NETGEAR advisory for specific fixed versions
Vendor Advisory: https://kb.netgear.com/000064479/Security-Advisory-for-Post-Authentication-Command-Injection-on-Some-Routers-and-WiFi-Systems-PSV-2020-0246
Restart Required: Yes
Instructions:
1. Log into router admin interface. 2. Navigate to Advanced > Administration > Firmware Update. 3. Check for updates and install latest firmware. 4. Reboot router after update completes.
🔧 Temporary Workarounds
Change Default Credentials
allChange all default admin passwords to strong, unique credentials to prevent unauthorized authentication.
Disable Remote Management
allDisable WAN-side administration to prevent external exploitation attempts.
🧯 If You Can't Patch
- Isolate affected routers in separate VLAN with strict firewall rules
- Implement network monitoring for unusual router traffic patterns
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface and compare against affected versions in NETGEAR advisory.Check Version:
Log into router web interface and navigate to Advanced > Administration > Firmware Update to view current version.Verify Fix Applied:
Confirm firmware version matches or exceeds the patched version listed in NETGEAR advisory.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in router logs
- Multiple failed authentication attempts followed by successful login
- Unexpected firmware or configuration changes
Network Indicators:
- Unusual outbound connections from router
- DNS queries to suspicious domains
- Unexpected port scans originating from router
SIEM Query:
source="router_logs" AND (event_type="command_execution" OR event_type="firmware_update")