CVE-2024-21876
📋 TL;DR
This path traversal vulnerability in Enphase IQ Gateway (formerly Envoy) allows unauthenticated attackers to access or create arbitrary files via URL parameter manipulation. It affects Envoy devices from version 4.x through 8.x, excluding patched version 8.2.4225. This exposes sensitive system files and could enable further system compromise.
💻 Affected Systems
- Enphase IQ Gateway
- Enphase Envoy
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise including credential theft, firmware modification, persistent backdoor installation, and potential lateral movement to connected solar/battery systems
Likely Case
Unauthorized access to configuration files, credentials, and sensitive system information leading to data exposure and potential gateway takeover
If Mitigated
Limited impact if proper network segmentation and access controls prevent external exploitation attempts
🎯 Exploit Status
Public exploit details available in DIVD advisory. Simple HTTP requests with crafted parameters can trigger the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 8.2.4225
Vendor Advisory: https://enphase.com/cybersecurity/advisories/ensa-2024-1
Restart Required: Yes
Instructions:
1. Log into Enphase Installer Toolkit 2. Check current firmware version 3. If below 8.2.4225, initiate firmware update 4. Wait for automatic restart and verification
🔧 Temporary Workarounds
Network Segmentation
allIsolate Enphase gateways from untrusted networks and internet access
Access Control Lists
allImplement firewall rules to restrict access to gateway management interface
🧯 If You Can't Patch
- Segment gateway on isolated VLAN with strict firewall rules
- Implement network monitoring for path traversal patterns in HTTP requests
🔍 How to Verify
Check if Vulnerable:
Check firmware version via Enphase Installer Toolkit or web interface. If version is between 4.x and 8.x and not 8.2.4225, device is vulnerable.Check Version:
curl -s http://[gateway-ip]/info | grep firmware_versionVerify Fix Applied:
Confirm firmware version shows 8.2.4225 or higher in Enphase Installer Toolkit📡 Detection & Monitoring
Log Indicators:
- HTTP requests with ../ patterns in URL parameters
- Unusual file access patterns in system logs
- Failed authentication attempts followed by file access
Network Indicators:
- HTTP requests containing path traversal sequences (../, ..\, %2e%2e%2f)
- Multiple file access attempts from single source
- Requests to unusual file paths on gateway
SIEM Query:
http.url:*%2e%2e%2f* OR http.url:*..%2f* OR http.url:*..\* destination.ip:[gateway-ip]