CVE-2020-25755
📋 TL;DR
This vulnerability allows authenticated remote attackers to execute arbitrary commands on Enphase Envoy solar energy monitoring devices via the force parameter in the upgrade_start function. It affects Envoy R3.x and D4.x devices and potentially other current models. Attackers with valid credentials can gain full system control.
💻 Affected Systems
- Enphase Envoy R3.x
- Enphase Envoy D4.x
- Other current Envoy devices
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the solar monitoring system allowing attackers to manipulate energy data, disrupt solar operations, pivot to internal networks, or install persistent backdoors.
Likely Case
Attackers with stolen or default credentials gain remote code execution to manipulate energy reporting, disrupt monitoring, or use the device as a foothold in the network.
If Mitigated
Limited to authenticated users only, with proper credential management and network segmentation preventing exploitation.
🎯 Exploit Status
Exploitation requires authentication but is straightforward once credentials are obtained. Public research demonstrates the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check with Enphase for specific firmware updates
Vendor Advisory: https://enphase.com/en-us/products-and-services/envoy-and-combiner
Restart Required: Yes
Instructions:
1. Check current firmware version. 2. Contact Enphase support for latest firmware. 3. Apply firmware update via web interface or installer tools. 4. Reboot device after update.
🔧 Temporary Workarounds
Network Segmentation
allIsolate Envoy devices from internet and restrict network access to management interfaces
Credential Hardening
allChange default credentials and implement strong authentication policies
🧯 If You Can't Patch
- Implement strict network access controls to limit who can reach the Envoy management interface
- Monitor for suspicious authentication attempts and command execution patterns
🔍 How to Verify
Check if Vulnerable:
Check if device is Envoy R3.x or D4.x model and has not received security updates. Attempting to access /installer/upgrade_start with force parameter (only in test environments).Check Version:
Check web interface at http://[envoy-ip]/info or via SSH if availableVerify Fix Applied:
Verify firmware version is updated to latest release from Enphase and test that force parameter no longer executes arbitrary commands.📡 Detection & Monitoring
Log Indicators:
- Unusual authentication attempts to Envoy
- Access to /installer/upgrade_start with force parameter
- Unexpected command execution or process creation
Network Indicators:
- Traffic to Envoy management ports from unusual sources
- Outbound connections from Envoy devices not related to normal operations
SIEM Query:
source_ip="*" AND destination_port="80" AND uri_path="/installer/upgrade_start" AND query_string="*force=*"🔗 References
- https://enphase.com/en-us/products-and-services/envoy-and-combiner
- https://medium.com/stage-2-security/can-solar-controllers-be-used-to-generate-fake-clean-energy-credits-4a7322e7661a
- https://stage2sec.com
- https://enphase.com/en-us/products-and-services/envoy-and-combiner
- https://medium.com/stage-2-security/can-solar-controllers-be-used-to-generate-fake-clean-energy-credits-4a7322e7661a
- https://stage2sec.com
