CVE-2017-5144
📋 TL;DR
This critical authentication bypass vulnerability in Carlo Gavazzi VMU-C energy monitoring devices allows attackers to access most application functions without credentials. Affected systems include VMU-C EM devices prior to firmware Version A11_U05 and VMU-C PV devices prior to firmware Version A17. This impacts industrial control systems using these devices for energy monitoring.
💻 Affected Systems
- Carlo Gavazzi VMU-C EM
- Carlo Gavazzi VMU-C PV
📦 What is this software?
Vmu C Em Firmware by Carlosgavazzi
Vmu C Pv Firmware by Carlosgavazzi
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of energy monitoring systems allowing unauthorized control, data manipulation, or disruption of industrial operations.
Likely Case
Unauthorized access to sensitive energy consumption data, configuration changes, or potential device manipulation.
If Mitigated
Limited impact if devices are isolated in protected networks with strict access controls.
🎯 Exploit Status
Authentication bypass vulnerabilities typically have low exploitation complexity once discovered.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: VMU-C EM: firmware Version A11_U05 or later, VMU-C PV: firmware Version A17 or later
Vendor Advisory: https://ics-cert.us-cert.gov/advisories/ICSA-17-012-03
Restart Required: Yes
Instructions:
1. Download latest firmware from Carlo Gavazzi support portal. 2. Backup current configuration. 3. Apply firmware update following vendor instructions. 4. Verify successful update and restore configuration if needed.
🔧 Temporary Workarounds
Network Segmentation
allIsolate affected devices in separate VLANs with strict firewall rules limiting access to authorized management systems only.
Access Control Lists
allImplement network ACLs to restrict access to device management interfaces to specific IP addresses only.
🧯 If You Can't Patch
- Segment network to isolate vulnerable devices from untrusted networks
- Implement strict firewall rules allowing only necessary traffic to device management interfaces
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface or serial console. For VMU-C EM: version must be A11_U05 or higher. For VMU-C PV: version must be A17 or higher.Check Version:
Access device web interface and navigate to System Information or use serial console to check firmware version.Verify Fix Applied:
After firmware update, verify version shows patched version and test that authentication is required for all application functions.📡 Detection & Monitoring
Log Indicators:
- Unauthenticated access attempts to application functions
- Configuration changes without authentication logs
Network Indicators:
- HTTP requests to device management interface without authentication headers
- Unusual traffic patterns to device ports
SIEM Query:
source_ip="device_ip" AND (http_status=200 OR http_method=POST) AND NOT (http_cookie CONTAINS "session" OR http_authorization EXISTS)