CVE-2021-45539
📋 TL;DR
This vulnerability allows authenticated attackers to execute arbitrary commands on affected NETGEAR routers and WiFi systems. It affects multiple NETGEAR device models running vulnerable firmware versions. Attackers must have valid credentials to exploit this command injection flaw.
💻 Affected Systems
- NETGEAR R7900P
- NETGEAR R7960P
- NETGEAR R8000
- NETGEAR R8000P
- NETGEAR MR60
- NETGEAR RAX20
- NETGEAR RAX45
- NETGEAR RAX80
- NETGEAR MS60
- NETGEAR RAX15
- NETGEAR RAX50
- NETGEAR RAX75
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attackers to install persistent backdoors, intercept network traffic, pivot to internal networks, or use the device for botnet activities.
Likely Case
Local network compromise, credential theft, DNS hijacking, or device configuration manipulation by authenticated malicious users.
If Mitigated
Limited impact if strong authentication controls are in place and network segmentation isolates the router management interface.
🎯 Exploit Status
Exploitation requires authenticated access but is straightforward once credentials are obtained. Public exploit code exists for similar NETGEAR vulnerabilities.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: R7900P/R7960P/R8000P: 1.4.2.84+, R8000: 1.0.4.74+, MR60/MS60: 1.0.6.110+, RAX20/RAX15: 1.0.2.82+, RAX45/RAX50: 1.0.2.28+, RAX80/RAX75: 1.0.3.106+
Vendor Advisory: https://kb.netgear.com/000064476/Security-Advisory-for-Post-Authentication-Command-Injection-on-Some-Routers-and-WiFi-Systems-PSV-2020-0195
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 router administration interface
Log into router > Advanced > Administration > Remote Management > Disable
Change default credentials
allUse strong, unique passwords for router administration
Log into router > Advanced > Administration > Set Password > Create strong password
🧯 If You Can't Patch
- Isolate router management interface to trusted VLAN only
- Implement network segmentation to limit router access to authorized administrators
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in web interface: Advanced > Administration > Firmware UpdateCheck Version:
Router-specific: Check via web interface or SSH if enabledVerify Fix Applied:
Verify firmware version matches or exceeds patched versions listed in vendor advisory📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in router logs
- Multiple failed login attempts followed by successful login
- Unexpected configuration changes
Network Indicators:
- Unusual outbound connections from router
- DNS changes not initiated by administrator
- Unexpected port openings on router
SIEM Query:
source="router_logs" AND (command="*;*" OR command="*|*" OR command="*`*" OR command="*$(*")