OTPulse

Hitachi Energy RTU500 series CMU

MonitorCVSS 5.9ICS-CERT ICSA-24-354-01Dec 19, 2024
Hitachi EnergyEnergy
Attack path
Attack VectorNetwork
Auth RequiredNone
ComplexityHigh
User InteractionNone needed
Summary

A buffer overflow vulnerability (CWE-120) in Hitachi Energy RTU500 series CMU (Communications Module) firmware versions 12.0.1 through 13.5.1 allows a remote attacker without authentication to cause a denial-of-service condition. Successful exploitation could crash or disable the CMU, interrupting communications between remote terminal units and the control center. The vulnerability requires high attack complexity and has low exploit probability (0.2% EPSS), but affects critical infrastructure communications.

What this means
What could happen
A denial-of-service attack against the RTU500 CMU could cause the communications module to stop functioning, disrupting remote monitoring and control of grid assets and potentially triggering alarm conditions or loss of visibility in the control center.
Who's at risk
Electric utilities and regional transmission operators that deploy Hitachi Energy RTU500 series remote terminal units for grid monitoring and control. Primary concern is for communications modules (CMU) that manage telemetry and control traffic between substations and control centers.
How it could be exploited
An attacker with network access to the RTU500 series CMU could send a specially crafted request that triggers a buffer overflow condition in the communications module, causing it to crash or become unresponsive and unable to process legitimate commands or telemetry.
Prerequisites
  • Network access to the RTU500 CMU (likely port for Modbus TCP or proprietary protocol)
  • No authentication required to trigger the vulnerability
remotely exploitableno authentication requiredhigh attack complexity (mitigating factor)affects critical grid visibility and control capability
Exploitability
Unlikely to be exploited — EPSS score 0.2%
Affected products (8)
8 pending
ProductAffected VersionsFix Status
RTU500 series CMU Firmware: >=12.0.1|<=12.0.14≥ 12.0.1|≤ 12.0.14No fix yet
RTU500 series CMU Firmware: >=12.2.1|<=12.2.11≥ 12.2.1|≤ 12.2.11No fix yet
RTU500 series CMU Firmware: >=12.4.1|<=12.4.11≥ 12.4.1|≤ 12.4.11No fix yet
RTU500 series CMU Firmware: >=12.6.1|<=12.6.9≥ 12.6.1|≤ 12.6.9No fix yet
RTU500 series CMU Firmware: >=12.7.1|<=12.7.6≥ 12.7.1|≤ 12.7.6No fix yet
RTU500 series CMU Firmware: >=13.2.1|<=13.2.6≥ 13.2.1|≤ 13.2.6No fix yet
RTU500 series CMU Firmware: >=13.4.1|<=13.4.3≥ 13.4.1|≤ 13.4.3No fix yet
RTU500 series CMU Firmware: 13.5.113.5.1No fix yet
Remediation & Mitigation
0/4
Do now
0/2
WORKAROUNDRestrict network access to RTU500 CMU to authorized control center stations and engineering workstations only using firewall rules; block inbound connections from untrusted networks
WORKAROUNDDisable or restrict remote access protocols on RTU500 CMU if not operationally required for your process control workflow
Schedule — requires maintenance window
0/1

Patching may require device reboot — plan for process interruption

HOTFIXUpdate RTU500 CMU firmware to version 12.0.15 or later (12.0 series), 12.2.12 or later (12.2 series), 12.4.12 or later (12.4 series), 12.6.10 or later (12.6 series), 12.7.7 or later (12.7 series), 13.2.7 or later (13.2 series), 13.4.4 or later (13.4 series), or 13.5.2 or later (13.5 series)
Long-term hardening
0/1
HARDENINGIsolate RTU500 devices from direct Internet connections and ensure they are separated from corporate IT networks by a firewall with minimal exposed ports
View full CISA ICS-CERT advisory
API: /api/v1/advisories/34aa8168-6c51-4315-9501-0f4db136c8a0

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