OTPulse

APsystems Energy Communication Unit (ECU-C) Power Control Software

Plan PatchCVSS 8.8ICS-CERT ICSA-24-023-01Jan 23, 2024
Energy
Attack path
Attack VectorAdjacent
Auth RequiredNone
ComplexityLow
User InteractionNone needed
Summary

A missing authentication mechanism in APSystems Energy Communication Unit (ECU-C) Power Control Software allows an attacker with network access to the device to execute arbitrary administrative commands and access sensitive data without valid credentials. The vulnerability affects all tested versions (C1.2.2, v3.11.4, W2.1.NA, v4.1SAA, v4.1NA). APSystems has not provided a patch and has not engaged with CISA on remediation. The vulnerability is classified as high severity (CVSS 8.8) due to high confidentiality, integrity, and availability impact. No public exploitation has been reported.

What this means
What could happen
An attacker with network access to the ECU-C device could bypass authentication and run administrative commands, potentially altering solar inverter setpoints, disabling power curtailment, or shutting down energy export functions without authorization.
Who's at risk
Solar energy operators and municipal utilities using APSystems ECU-C devices for inverter management and power export control. This affects sites where the ECU-C is installed to coordinate distributed solar inverters, particularly those with grid-export or demand-response capabilities.
How it could be exploited
An attacker on the local network segment (Layer 2 or routed access) to the ECU-C device can send specially crafted requests to access administrative functions and execute commands without providing credentials. The low complexity of the attack (AC:L) means no special tools or timing are required.
Prerequisites
  • Network access to the ECU-C device (adjacent network or routed IP connectivity)
  • No credentials required
No authentication requiredLow complexity attackNo patch availableAffects energy infrastructure
Exploitability
Unlikely to be exploited — EPSS score 0.1%
Affected products (5)
5 pending
ProductAffected VersionsFix Status
Energy Communication Unit Power Control Software: C1.2.2C1.2.2No fix yet
Energy Communication Unit Power Control Software: v3.11.4v3.11.4No fix yet
Energy Communication Unit Power Control Software: W2.1.NAW2.1.NANo fix yet
Energy Communication Unit Power Control Software: v4.1SAAv4.1SAANo fix yet
Energy Communication Unit Power Control Software: v4.1NAv4.1NANo fix yet
Remediation & Mitigation
0/4
Do now
0/3
HARDENINGRestrict network access to the ECU-C device by placing it behind a firewall and denying all inbound access except from authorized engineering and monitoring systems
HARDENINGIsolate the ECU-C device and associated solar control systems on a dedicated VLAN or network segment, separate from business IT networks
HARDENINGIf remote access to the ECU-C is required, implement a secure VPN gateway and restrict access to specific source IP addresses
Schedule — requires maintenance window
0/1

Patching may require device reboot — plan for process interruption

HARDENINGMonitor ECU-C network traffic for unauthorized access attempts and implement alerting on administrative function calls
View full CISA ICS-CERT advisory
API: /api/v1/advisories/a07ba19a-8c14-48df-b2fa-451640e2b638

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