CVE-2021-29075
📋 TL;DR
This CVE describes a stack-based buffer overflow vulnerability in certain NETGEAR WiFi systems that allows an authenticated attacker to execute arbitrary code or cause denial of service. The vulnerability affects multiple NETGEAR Orbi WiFi 6 mesh systems and requires authentication to exploit. Attackers with valid credentials could potentially gain full control of affected devices.
💻 Affected Systems
- NETGEAR RBW30
- NETGEAR RBK852
- NETGEAR RBR850
- NETGEAR RBS850
- NETGEAR RBK752
- NETGEAR RBK753
- NETGEAR RBK753S
- NETGEAR RBK754
- NETGEAR RBR750
- NETGEAR RBS750
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attacker to install persistent malware, intercept network traffic, pivot to other network devices, or brick the device permanently.
Likely Case
Device crash/reboot causing temporary network disruption, or limited code execution within device constraints.
If Mitigated
No impact if proper authentication controls prevent unauthorized access and devices are properly segmented.
🎯 Exploit Status
Requires authenticated access, making exploitation more difficult than unauthenticated vulnerabilities. Stack-based buffer overflows typically require specific knowledge of memory layout.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: RBW30: 2.6.2.2 or later; All other models: 3.2.17.12 or later
Vendor Advisory: https://kb.netgear.com/000063010/Security-Advisory-for-Post-Authentication-Stack-Overflow-on-Some-WiFi-Systems-PSV-2020-0466
Restart Required: Yes
Instructions:
1. Log into NETGEAR Orbi web 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. Device will reboot automatically after update.
🔧 Temporary Workarounds
Restrict administrative access
allLimit administrative interface access to trusted IP addresses only
Strong authentication controls
allImplement complex passwords, multi-factor authentication if supported, and regular credential rotation
🧯 If You Can't Patch
- Segment affected devices on isolated network segments to limit lateral movement
- Implement strict network monitoring for unusual authentication attempts or device behavior
🔍 How to Verify
Check if Vulnerable:
Check firmware version in Orbi web interface: Advanced > Administration > Firmware UpdateCheck Version:
Web interface only - no CLI command availableVerify Fix Applied:
Verify firmware version is RBW30: 2.6.2.2+ or other models: 3.2.17.12+📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts followed by successful login
- Unusual administrative access patterns
- Device crash/reboot logs
Network Indicators:
- Unusual outbound connections from router
- Traffic patterns suggesting device compromise
SIEM Query:
source="netgear-router" AND (event_type="authentication" AND result="success" FROM suspicious_ip) OR event_type="system_reboot"