CVE-2021-21940
📋 TL;DR
A heap-based buffer overflow vulnerability in Anker Eufy Homebase 2's RTSP handling allows remote code execution. Attackers can send malicious network packets to trigger this vulnerability, potentially taking full control of affected devices. This affects Eufy Homebase 2 devices running vulnerable firmware versions.
💻 Affected Systems
- Anker Eufy Homebase 2
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, data exfiltration, and pivot to internal network.
Likely Case
Remote code execution allowing attacker to run arbitrary commands on the device, potentially accessing camera feeds and user data.
If Mitigated
Limited impact if device is behind firewall with strict network controls and isolated from critical systems.
🎯 Exploit Status
Exploit requires sending specially crafted RTSP packets. Public technical details available in Talos report.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.1.8.5h and later
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 update 2.1.8.5h or later 5. Device will restart automatically
🔧 Temporary Workarounds
Network Segmentation
allIsolate Homebase 2 from internet and restrict network access
Firewall Rules
linuxBlock RTSP port (554) access from untrusted networks
iptables -A INPUT -p tcp --dport 554 -j DROP
iptables -A INPUT -p udp --dport 554 -j DROP
🧯 If You Can't Patch
- Disable RTSP functionality in device settings if not required
- Place device behind VPN with strict access controls
🔍 How to Verify
Check if Vulnerable:
Check firmware version in Eufy Security app: Settings > General > About Device > Firmware VersionCheck Version:
Not applicable - check via mobile app interfaceVerify Fix Applied:
Confirm firmware version is 2.1.8.5h or later in device settings📡 Detection & Monitoring
Log Indicators:
- Unusual RTSP packet sizes
- Process crashes in pushMuxer
- Memory corruption errors
Network Indicators:
- Malformed RTSP packets to port 554
- Unusual outbound connections from Homebase
SIEM Query:
source_ip="*" AND dest_port=554 AND (packet_size>threshold OR protocol_anomaly=true)