CVE-2021-45732
📋 TL;DR
CVE-2021-45732 is a hardcoded credential vulnerability in Netgear Nighthawk R6700 routers that allows attackers to decrypt configuration backups, modify restricted settings, and restore malicious configurations. This affects users of Netgear Nighthawk R6700 routers running vulnerable firmware versions. Attackers can change router settings that should be protected, potentially compromising network security.
💻 Affected Systems
- Netgear Nighthawk R6700
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router takeover allowing DNS hijacking, traffic interception, credential theft, and persistent backdoor installation across the entire network.
Likely Case
Unauthorized configuration changes enabling network monitoring, service disruption, or credential harvesting from connected devices.
If Mitigated
Limited impact with proper network segmentation and monitoring, though router configuration integrity remains compromised.
🎯 Exploit Status
Public tools exist for configuration extraction/repackaging. Exploitation requires access to router backup/restore functionality, which typically requires authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Later versions than 1.0.4.120
Vendor Advisory: https://kb.netgear.com/000064437/Security-Advisory-for-Hardcoded-Credential-Vulnerability-on-Some-Routers-PSV-2021-0294
Restart Required: Yes
Instructions:
1. Log into router admin 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
allPrevents external attackers from accessing router administration interface
Disable configuration backup/restore
allRemove ability to upload modified configurations if feature not needed
🧯 If You Can't Patch
- Isolate router on separate VLAN with strict firewall rules
- Monitor for unauthorized configuration changes and backup file uploads
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under Advanced > Administration > Firmware UpdateCheck Version:
Not applicable - check via web interfaceVerify Fix Applied:
Confirm firmware version is later than 1.0.4.120 and attempt to extract/decrypt configuration backup using public tools should fail📡 Detection & Monitoring
Log Indicators:
- Unusual configuration backup/restore events
- Multiple failed login attempts followed by configuration changes
Network Indicators:
- Unexpected DNS server changes
- Unusual outbound traffic patterns from router
SIEM Query:
source="router_logs" AND (event="configuration_restore" OR event="backup_upload")