CVE-2021-45609
📋 TL;DR
This vulnerability allows unauthenticated remote attackers to execute arbitrary code on affected NETGEAR routers via a buffer overflow. It affects multiple NETGEAR router models running outdated firmware versions. Attackers can exploit this without any authentication to potentially take full control of the device.
💻 Affected Systems
- NETGEAR D8500
- NETGEAR R6250
- NETGEAR R7000
- NETGEAR R7100LG
- NETGEAR R7900
- NETGEAR R8300
- NETGEAR R8500
- NETGEAR XR300
- NETGEAR R7000P
- NETGEAR R6900P
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, credential theft, and lateral movement to other devices on the network.
Likely Case
Remote code execution allowing attackers to modify router settings, redirect traffic, or use the device as part of a botnet.
If Mitigated
No impact if patched firmware is installed or if the device is not internet-facing with proper network segmentation.
🎯 Exploit Status
Public exploit code exists and the vulnerability is easily exploitable without authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: D8500 1.0.3.58+, R6250 1.0.4.48+, R7000 1.0.11.116+, R7100LG 1.0.0.64+, R7900 1.0.4.38+, R8300 1.0.2.144+, R8500 1.0.2.144+, XR300 1.0.3.68+, R7000P 1.3.2.132+, R6900P 1.3.2.132+
Vendor Advisory: https://kb.netgear.com/000064483/Security-Advisory-for-Pre-Authentication-Buffer-Overflow-on-Some-Routers-PSV-2020-0274
Restart Required: Yes
Instructions:
1. Log into router admin interface. 2. Navigate to Advanced > Administration > Firmware Update. 3. Check for updates and install latest firmware. 4. Reboot router after update completes.
🔧 Temporary Workarounds
Disable remote management
allPrevents external exploitation by disabling remote administration features
Network segmentation
allPlace routers in isolated network segments to limit lateral movement
🧯 If You Can't Patch
- Replace affected devices with supported models
- Implement strict firewall rules to block all inbound traffic to router management interfaces
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under Advanced > Administration > Firmware UpdateCheck Version:
Check via router web interface or use nmap/router scanning toolsVerify Fix Applied:
Confirm firmware version matches or exceeds patched versions listed in vendor advisory📡 Detection & Monitoring
Log Indicators:
- Unusual buffer overflow errors in router logs
- Multiple failed exploit attempts
- Unexpected configuration changes
Network Indicators:
- Unusual outbound connections from router
- Traffic redirection patterns
- Exploit payload patterns in network traffic
SIEM Query:
source="router_logs" AND ("buffer overflow" OR "segmentation fault" OR exploit_patterns)