CVE-2021-45553
📋 TL;DR
This vulnerability allows authenticated attackers to execute arbitrary commands on affected NETGEAR routers. It affects R7000, R6900P, and R7000P models running outdated firmware versions. Attackers must have valid credentials to exploit this command injection flaw.
💻 Affected Systems
- NETGEAR R7000
- NETGEAR R6900P
- NETGEAR R7000P
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router compromise allowing attackers to intercept all network traffic, install persistent malware, pivot to internal networks, and disable security features.
Likely Case
Router takeover enabling traffic monitoring, DNS hijacking, credential theft, and installation of backdoors for future access.
If Mitigated
Limited impact if strong authentication controls, network segmentation, and monitoring are in place to detect unusual authenticated activity.
🎯 Exploit Status
Exploitation requires valid credentials but is straightforward once authenticated. Public exploit code exists.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: R7000: 1.0.11.126+, R6900P/R7000P: 1.3.2.126+
Vendor Advisory: https://kb.netgear.com/000064074/Security-Advisory-for-Post-Authentication-Command-Injection-on-Some-Routers-PSV-2019-0225
Restart Required: Yes
Instructions:
1. Log into router web interface. 2. Navigate to Advanced > Administration > Firmware Update. 3. Check for updates or manually download from NETGEAR support site. 4. Upload and install firmware. 5. Router will reboot automatically.
🔧 Temporary Workarounds
Change Default Credentials
allChange default admin passwords to strong, unique credentials to reduce attack surface.
Disable Remote Management
allTurn off remote administration to prevent external authentication attempts.
🧯 If You Can't Patch
- Implement network segmentation to isolate router management interface
- Enable logging and monitor for unusual authenticated access patterns
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface under Advanced > Administration > Firmware UpdateCheck Version:
Not applicable - check via web interfaceVerify Fix Applied:
Confirm firmware version matches or exceeds patched versions: R7000 >= 1.0.11.126, R6900P/R7000P >= 1.3.2.126📡 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 queries to suspicious domains
- Traffic redirection patterns
SIEM Query:
source="router_logs" AND (command_injection OR shell_exec OR system_call)