CVE-2021-45506
📋 TL;DR
This CVE describes an authentication bypass vulnerability in specific NETGEAR WiFi systems. Attackers can potentially gain unauthorized access to device administration interfaces without valid credentials. Affected users include those using NETGEAR CBR750, RBK752/RBR750/RBS750, and RBK852/RBR850/RBS850 systems with firmware versions below the patched releases.
💻 Affected Systems
- NETGEAR CBR750
- NETGEAR RBK752
- NETGEAR RBR750
- NETGEAR RBS750
- NETGEAR RBK852
- NETGEAR RBR850
- NETGEAR RBS850
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the WiFi system allowing attackers to reconfigure network settings, intercept traffic, deploy malware to connected devices, or use the device as a pivot point into the internal network.
Likely Case
Unauthorized access to router administration panel leading to network configuration changes, DNS hijacking, or credential theft from connected devices.
If Mitigated
Limited impact if device is not internet-facing and network segmentation prevents lateral movement from compromised device.
🎯 Exploit Status
Authentication bypass vulnerabilities typically have low exploitation complexity. No public exploit code has been identified, but the high CVSS score suggests significant impact if exploited.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: CBR750: 4.6.3.6 or later; RBK752/RBR750/RBS750: 3.2.17.12 or later; RBK852/RBR850/RBS850: 3.2.17.12 or later
Vendor Advisory: https://kb.netgear.com/000064130/Security-Advisory-for-Authentication-Bypass-on-Some-WiFi-Systems-PSV-2020-0483
Restart Required: Yes
Instructions:
1. Log into NETGEAR router admin interface. 2. Navigate to Advanced > Administration > Firmware Update. 3. Check for updates and apply if available. 4. Alternatively, download firmware from NETGEAR support site and manually upload. 5. Reboot device after update completes.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to administration interface
Network Segmentation
allIsolate affected devices from critical network segments
🧯 If You Can't Patch
- Replace affected devices with patched models or alternative vendors
- Implement strict network access controls to limit exposure of administration interfaces
🔍 How to Verify
Check if Vulnerable:
Access router admin interface and check firmware version in Advanced > Administration > Firmware Update or similar menuCheck Version:
No CLI command; check via web interface at router IP address (typically 192.168.1.1 or 10.0.0.1)Verify Fix Applied:
Confirm firmware version matches or exceeds patched versions: CBR750 >= 4.6.3.6, RBK752/RBR750/RBS750 >= 3.2.17.12, RBK852/RBR850/RBS850 >= 3.2.17.12📡 Detection & Monitoring
Log Indicators:
- Unauthorized access attempts to admin interface
- Successful admin logins from unexpected IP addresses
- Configuration changes without authorized user activity
Network Indicators:
- HTTP/HTTPS traffic to router admin port from external IPs
- Unusual outbound connections from router
SIEM Query:
source_ip=external AND dest_ip=router_ip AND dest_port IN (80,443,8080) AND http_user_agent CONTAINS 'admin'