CVE-2021-21950
📋 TL;DR
This critical vulnerability allows remote code execution on Anker Eufy Homebase 2 devices via specially crafted network packets. Attackers can exploit an out-of-bounds write in the home_security binary to execute arbitrary code with full system control. All users of affected Eufy Homebase 2 devices are at risk.
💻 Affected Systems
- Anker Eufy Homebase 2
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attackers to install persistent malware, access security camera feeds, pivot to other network devices, and disable security systems.
Likely Case
Remote code execution leading to device takeover, surveillance system compromise, and potential access to connected smart home devices.
If Mitigated
Limited impact if devices are isolated from internet and untrusted networks, with network segmentation preventing lateral movement.
🎯 Exploit Status
Talos Intelligence published detailed technical analysis including proof-of-concept. The vulnerability requires sending crafted packets to port 4433/TCP.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check with vendor for latest firmware
Vendor Advisory: https://us.eufylife.com/pages/security
Restart Required: Yes
Instructions:
1. Log into Eufy Security app. 2. Navigate to device settings. 3. Check for firmware updates. 4. Apply available updates. 5. Reboot device after update.
🔧 Temporary Workarounds
Network Isolation
linuxBlock inbound access to Homebase device on port 4433/TCP from untrusted networks
iptables -A INPUT -p tcp --dport 4433 -j DROP
VLAN Segmentation
allPlace Homebase devices on isolated VLAN separate from critical network segments
🧯 If You Can't Patch
- Disable remote access features in Eufy Security app settings
- Implement strict firewall rules blocking all inbound traffic to Homebase except from mobile app IP ranges
🔍 How to Verify
Check if Vulnerable:
Check firmware version in Eufy Security app under device settings. Versions 2.1.6.9h and earlier are vulnerable.Check Version:
Check via Eufy Security mobile app: Device Settings > About > Firmware VersionVerify Fix Applied:
Verify firmware version is updated beyond 2.1.6.9h. Test by attempting to connect to port 4433/TCP - service should respond normally to legitimate requests only.📡 Detection & Monitoring
Log Indicators:
- Unusual process execution from home_security binary
- Crash logs from home_security service
- Multiple connection attempts to port 4433
Network Indicators:
- Unusual traffic patterns to port 4433/TCP
- Malformed packets to Homebase device
- Outbound connections from Homebase to suspicious IPs
SIEM Query:
source="firewall" dest_port=4433 AND (packet_size>normal OR protocol_anomaly=true)