CVE-2021-45561

8.4 HIGH

📋 TL;DR

This vulnerability allows authenticated attackers to execute arbitrary commands on affected NETGEAR WiFi systems. It affects RBK752, RBR750, RBS750, RBK852, RBR850, and RBS850 devices running firmware versions before 3.2.16.6. Attackers with valid credentials can inject malicious commands through vulnerable interfaces.

💻 Affected Systems

Products:
  • NETGEAR RBK752
  • NETGEAR RBR750
  • NETGEAR RBS750
  • NETGEAR RBK852
  • NETGEAR RBR850
  • NETGEAR RBS850
Versions: All versions before 3.2.16.6
Operating Systems: Embedded firmware
Default Config Vulnerable: ⚠️ Yes
Notes: Affects both router and satellite units in these WiFi 6 mesh systems. Authentication required for exploitation.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete device compromise leading to network infiltration, data exfiltration, or use as pivot point for lateral movement within the network.

🟠

Likely Case

Local privilege escalation allowing attackers to modify device settings, intercept network traffic, or install persistent backdoors.

🟢

If Mitigated

Limited impact if strong authentication controls and network segmentation prevent unauthorized access to management interfaces.

🌐 Internet-Facing: MEDIUM - Risk exists if management interfaces are exposed to internet, though authentication is required.
🏢 Internal Only: HIGH - Internal attackers with credentials can exploit this to gain full control of affected devices.

🎯 Exploit Status

Public PoC: ✅ No
Weaponized: UNKNOWN
Unauthenticated Exploit: ✅ No
Complexity: LOW

Requires authenticated access to vulnerable interface. No public exploit code available as of analysis.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 3.2.16.6 or later

Vendor Advisory: https://kb.netgear.com/000064165/Security-Advisory-for-Post-Authentication-Command-Injection-on-Some-WiFi-Systems-PSV-2020-0059

Restart Required: Yes

Instructions:

1. Log into NETGEAR router web interface. 2. Navigate to Advanced > Administration > Firmware Update. 3. Check for updates and install version 3.2.16.6 or later. 4. Reboot device after update completes.

🔧 Temporary Workarounds

Restrict Management Access

all

Limit access to router management interface to trusted IP addresses only

Strong Authentication Enforcement

all

Implement complex passwords and multi-factor authentication if supported

🧯 If You Can't Patch

  • Isolate affected devices in separate VLAN with strict firewall rules
  • Implement network monitoring for suspicious command execution patterns

🔍 How to Verify

Check if Vulnerable:

Check firmware version in router web interface under Advanced > Administration > Firmware Update

Check Version:

Not applicable - check via web interface or mobile app

Verify Fix Applied:

Confirm firmware version is 3.2.16.6 or higher in the same location

📡 Detection & Monitoring

Log Indicators:

  • Unusual command execution in system logs
  • Multiple failed authentication attempts followed by successful login

Network Indicators:

  • Unexpected outbound connections from router
  • Unusual traffic patterns from router management interface

SIEM Query:

source="netgear-router" AND (event_type="command_execution" OR event_type="system_modification")

🔗 References

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