CVE-2021-45573
📋 TL;DR
This CVE describes a stack-based buffer overflow vulnerability in multiple NETGEAR router models that allows unauthenticated remote attackers to execute arbitrary code. The vulnerability affects specific firmware versions of NETGEAR R6260, R6800, R6700v2, R6900v2, R7450, AC2100, AC2400, and AC2600 routers. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 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
Complete device compromise allowing attacker to install persistent malware, intercept all network traffic, pivot to internal networks, and use device as part of botnet.
Likely Case
Device takeover leading to network traffic interception, DNS hijacking, credential theft, and lateral movement to connected devices.
If Mitigated
Limited impact if device is behind firewall with strict inbound rules, though internal network exposure remains.
🎯 Exploit Status
Buffer overflow vulnerabilities in network devices are frequently weaponized. The unauthenticated nature and CVSS 8.3 score make this attractive to attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: R6260: 1.1.0.76 or later; All others: 1.2.0.62 or later
Vendor Advisory: https://kb.netgear.com/000064095/Security-Advisory-for-Post-Authentication-Command-Injection-on-Some-WiFi-Systems-PSV-2020-0081
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
Network Segmentation
allPlace affected routers behind firewall with strict inbound rules to limit exposure.
Disable Remote Management
allTurn off remote administration features to reduce attack surface.
🧯 If You Can't Patch
- Replace affected devices with patched models or different vendors
- Implement strict network monitoring and intrusion detection for suspicious traffic to/from routers
🔍 How to Verify
Check if Vulnerable:
Check router admin interface > Advanced > Administration > Firmware Update for current version. Compare against affected versions list.Check Version:
Router-specific: Log into web interface at 192.168.1.1 or routerlogin.net and check firmware version in settings.Verify Fix Applied:
Confirm firmware version is R6260: 1.1.0.76+ or others: 1.2.0.62+ in router admin interface.📡 Detection & Monitoring
Log Indicators:
- Unusual authentication attempts
- Firmware modification logs
- Crash/reboot events
- Unusual outbound connections from router
Network Indicators:
- Unexpected traffic patterns from router
- DNS queries to suspicious domains
- Port scanning originating from router
SIEM Query:
source="router_logs" AND (event_type="firmware_change" OR event_type="crash" OR auth_failure_count>10)