CVE-2020-21989
📋 TL;DR
CVE-2020-21989 is a Cross-Site Request Forgery vulnerability in HomeAutomation 3.3.2 that allows attackers to trick authenticated users into performing unauthorized actions via malicious web requests. This affects all users of HomeAutomation 3.3.2 who have administrative or user accounts, potentially leading to system compromise.
💻 Affected Systems
- HomeAutomation
📦 What is this software?
Homeautomation by Homeautomation Project
⚠️ Risk & Real-World Impact
Worst Case
Complete system takeover where an attacker can reconfigure the entire home automation system, disable security features, or execute arbitrary commands with administrative privileges.
Likely Case
Unauthorized configuration changes to home automation devices, enabling/disabling security systems, or modifying user access controls.
If Mitigated
Limited impact with proper CSRF protections, network segmentation, and user awareness training preventing successful exploitation.
🎯 Exploit Status
Exploitation requires the victim to be authenticated and visit a malicious website. Public exploit code is available in Exploit-DB.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.3.3 or later
Vendor Advisory: https://www.zeroscience.mk/en/vulnerabilities/ZSL-2019-5558.php
Restart Required: Yes
Instructions:
1. Backup current configuration. 2. Download and install HomeAutomation 3.3.3 or later from official vendor. 3. Restart the HomeAutomation service. 4. Verify CSRF tokens are now required for all state-changing requests.
🔧 Temporary Workarounds
Implement CSRF Protection
allAdd CSRF tokens to all forms and state-changing endpoints
Modify web application to include anti-CSRF tokens in all POST/PUT/DELETE requests
Network Segmentation
allIsolate HomeAutomation system from untrusted networks
Configure firewall to restrict access to HomeAutomation web interface from trusted IPs only
🧯 If You Can't Patch
- Implement strict SameSite cookie policies and require re-authentication for sensitive actions
- Deploy a web application firewall (WAF) with CSRF protection rules and monitor for suspicious requests
🔍 How to Verify
Check if Vulnerable:
Check if HomeAutomation version is 3.3.2 and test if state-changing requests (POST/PUT/DELETE) accept requests without CSRF tokensCheck Version:
Check web interface footer or configuration file for version informationVerify Fix Applied:
Verify version is 3.3.3 or later and test that all state-changing requests require valid CSRF tokens📡 Detection & Monitoring
Log Indicators:
- Multiple failed CSRF token validations
- Sensitive configuration changes from unexpected IP addresses
- Rapid succession of administrative actions
Network Indicators:
- HTTP POST requests without Referer headers or CSRF tokens to HomeAutomation endpoints
- Requests originating from known malicious domains
SIEM Query:
source="homeautomation.log" AND ("POST" OR "PUT" OR "DELETE") AND NOT "csrf_token="