CVE-2020-22000
📋 TL;DR
CVE-2020-22000 allows authenticated attackers to execute arbitrary operating system commands on HomeAutomation systems through a vulnerable plugin. Combined with a CSRF vulnerability, this can be exploited remotely to gain shell access as the web server user. This affects HomeAutomation version 3.3.2 installations with the custom command plugin enabled.
💻 Affected Systems
- HomeAutomation
📦 What is this software?
Homeautomation by Homeautomation Project
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise leading to data theft, ransomware deployment, or use as a pivot point into internal networks
Likely Case
Web server compromise leading to data exfiltration, installation of backdoors, or cryptocurrency mining
If Mitigated
Limited impact with proper network segmentation and least privilege controls
🎯 Exploit Status
Exploit requires authenticated access but can be combined with CSRF for remote exploitation
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
1. Remove or disable the custom command plugin
2. Delete /system/systemplugins/customcommand/ directory
3. Check for any unauthorized modifications to the system
🔧 Temporary Workarounds
Disable Custom Command Plugin
linuxRemove or disable the vulnerable plugin to prevent exploitation
rm -rf /path/to/homeautomation/system/systemplugins/customcommand/
Input Validation Filter
allAdd input sanitization to the customcommand.plugin.php file
Edit customcommand.plugin.php and replace exec() calls with escapeshellarg() or similar sanitization
🧯 If You Can't Patch
- Implement strict network segmentation to isolate HomeAutomation system
- Apply web application firewall rules to block requests containing 'set_command_on' or 'set_command_off' parameters
🔍 How to Verify
Check if Vulnerable:
Check if /system/systemplugins/customcommand/customcommand.plugin.php exists and contains unsanitized exec() callsCheck Version:
Check HomeAutomation version in admin panel or configuration filesVerify Fix Applied:
Verify the customcommand.plugin.php file no longer exists or has been properly sanitized📡 Detection & Monitoring
Log Indicators:
- POST requests to customcommand.plugin.php with set_command_on/set_command_off parameters
- Unusual process execution from web server user
- Suspicious shell commands in web logs
Network Indicators:
- HTTP POST requests containing shell metacharacters or commands
- Outbound connections from web server to unusual destinations
SIEM Query:
source="web_logs" AND (uri="*customcommand.plugin.php*" AND (param="*set_command_on*" OR param="*set_command_off*"))