CVE-2021-45637
📋 TL;DR
This vulnerability allows unauthenticated attackers to trigger a stack-based buffer overflow on affected NETGEAR routers. Successful exploitation could lead to remote code execution or device crashes. Users with specific NETGEAR router models running outdated firmware are affected.
💻 Affected Systems
- NETGEAR R6260
- NETGEAR R6800
- NETGEAR R6700v2
- NETGEAR R6900v2
- NETGEAR R7450
- NETGEAR AC2100
- NETGEAR AC2400
- NETGEAR AC2600
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with full device compromise, allowing attacker to intercept traffic, modify router settings, or use device as pivot point into internal network.
Likely Case
Router crash/reboot causing denial of service, potentially requiring manual intervention to restore connectivity.
If Mitigated
No impact if patched firmware is installed or if router is not internet-facing with proper network segmentation.
🎯 Exploit Status
Exploitation requires no authentication and has been publicly demonstrated. The vulnerability is in the web interface/management service.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: R6260: 1.1.0.76 or later, others: 1.2.0.62 or later
Vendor Advisory: https://kb.netgear.com/000064059/Security-Advisory-for-Pre-Authentication-Stack-Overflow-on-Some-Routers-PSV-2019-0081
Restart Required: Yes
Instructions:
1. Log into router web interface. 2. Navigate to Advanced > Administration > Firmware Update. 3. Check for updates or manually download from NETGEAR support site. 4. Upload firmware file and follow update process. 5. Router will reboot automatically.
🔧 Temporary Workarounds
Disable remote management
allPrevents external attackers from accessing the vulnerable web interface
Network segmentation
allPlace router on isolated network segment to limit attack surface
🧯 If You Can't Patch
- Replace affected router with updated model or different vendor
- Implement strict firewall rules to block all inbound traffic to router management interface
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface: Advanced > Administration > Firmware UpdateCheck Version:
Not applicable - check via web interface or router admin panelVerify Fix Applied:
Confirm firmware version is R6260: 1.1.0.76+ or others: 1.2.0.62+📡 Detection & Monitoring
Log Indicators:
- Multiple failed connection attempts to router management interface
- Router reboot events without user action
- Unusual traffic patterns from router
Network Indicators:
- Unusual HTTP requests to router management port (typically 80/443)
- Traffic spikes to router from external IPs
SIEM Query:
source_ip=external AND dest_port=80 AND dest_ip=router_ip AND (uri_contains="admin" OR user_agent_contains="exploit")