CVE-2020-26926
📋 TL;DR
This vulnerability allows attackers to bypass authentication on affected NETGEAR WiFi systems, potentially gaining unauthorized access to network administration interfaces. It affects specific NETGEAR Orbi and Nighthawk WiFi system models running vulnerable firmware versions. Attackers could exploit this without valid credentials.
💻 Affected Systems
- NETGEAR CBR40
- 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 attacker to reconfigure network settings, intercept traffic, install malicious firmware, or pivot to connected devices.
Likely Case
Unauthorized access to router administration panel leading to network configuration changes, DNS hijacking, or credential theft.
If Mitigated
Limited impact if strong network segmentation, firewall rules, and monitoring are in place to detect unauthorized access attempts.
🎯 Exploit Status
Authentication bypass vulnerabilities typically have low exploitation complexity once the method is known. No public exploit code has been disclosed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: CBR40: 2.5.0.10; RBK752/RBR750/RBS750: 3.2.15.25; RBK852/RBR850/RBS850: 3.2.10.11
Vendor Advisory: https://kb.netgear.com/000062326/Security-Advisory-for-Authentication-Bypass-on-Some-WiFi-Systems-PSV-2020-0028
Restart Required: Yes
Instructions:
1. Log into 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.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to administration interface by disabling remote management features.
Network Segmentation
allPlace affected devices in isolated VLANs with strict firewall rules limiting access to administration interfaces.
🧯 If You Can't Patch
- Implement strict network access controls to limit who can reach the router administration interface
- Enable logging and monitoring for unauthorized access attempts to admin interfaces
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router admin interface under Advanced > Administration > Firmware Update or via NETGEAR Nighthawk app.Check Version:
No CLI command; check via web interface or mobile appVerify Fix Applied:
Confirm firmware version matches or exceeds patched versions: CBR40 >= 2.5.0.10, RBK752/RBR750/RBS750 >= 3.2.15.25, RBK852/RBR850/RBS850 >= 3.2.10.11📡 Detection & Monitoring
Log Indicators:
- Unauthorized access to admin pages
- Failed authentication attempts followed by successful access
- Configuration changes from unexpected IP addresses
Network Indicators:
- HTTP requests to admin endpoints without proper authentication headers
- Unusual traffic patterns to router management ports
SIEM Query:
Example: (destination_port:80 OR destination_port:443) AND (uri_path:"/admin" OR uri_path:"/cgi-bin") AND NOT (user_agent:"NETGEAR" OR source_ip:[trusted_admin_ips])