Modicon PAC Controllers and PLC Simulator for EcoStruxure™ Control Expert and EcoStruxure™ Process Expert
MonitorCVSS 6.5SEVD-2021-222-04Aug 10, 2021
Schneider ElectricEnergyManufacturing
Attack path
Attack VectorNetwork
Auth RequiredLow
ComplexityLow
User InteractionNone needed
Summary
Multiple vulnerabilities (CWE-119, CWE-125, CWE-787, CWE-476) in Modicon PAC Controllers and PLC Simulator allow an attacker to craft a malicious project file that, when downloaded to the controller, causes a buffer overflow or memory access violation resulting in loss of availability. The PLC Simulator is not intended for production use. Affected products include Modicon M580, M580 Safety, M340, MC80, Momentum, Legacy Modicon Premium and Quantum, and PLC Simulator for EcoStruxure Control Expert and Process Expert.
What this means
What could happen
An attacker with access to upload a malicious project file could stop a Modicon controller or PLC simulator, causing loss of availability for industrial operations like power distribution or manufacturing processes.
Who's at risk
Energy utilities and manufacturing plants using Schneider Electric Modicon M580, M580 Safety, M340, MC80, or Momentum CPU controllers, as well as engineering teams using PLC Simulator in EcoStruxure Control Expert or Process Expert software. Legacy Modicon Premium and Quantum systems are also affected.
How it could be exploited
An attacker obtains a valid project file (either legitimate or by compromising a workstation), modifies it maliciously, and uploads it to the target Modicon PLC or PLC Simulator. The controller processes the malicious file, triggering a buffer overflow or memory access violation that crashes the device and stops all operations it controls.
Prerequisites
- Ability to upload a project file to the controller (requires engineering access via EcoStruxure Control Expert / Process Expert software or direct project file transfer capability
- Knowledge of the target controller model and firmware version
- A crafted or modified project file
Remotely exploitable (via project file upload)Requires valid engineering accessLow complexity attack once access is gainedNo patch available for legacy Modicon Premium, Quantum, and Modicon Premium CPUNo patch available for PLC SimulatorAffects availability of industrial control systems
Exploitability
Unlikely to be exploited — EPSS score 0.5%
Affected products (9)
5 with fix2 pending2 EOL
ProductAffected VersionsFix Status
Modicon M580 CPU <SV4.10<SV4.10SV4.10
Modicon M580 CPU Safety (part numbers BMEP58*S and BMEH58*S)< SV4.21SV4.21
Modicon M340 CPU <3.50<3.503.50
Modicon MC80 <SV1.90< SV1.90All versions
PLC Simulator for EcoStruxure™ Control Expert All versionsAll versionsNo fix yet
PLC Simulator for EcoStruxure™ Process Expert All versionsAll versionsNo fix yet
Legacy Modicon Premium and Quantum All versionsAll versionsNo fix (EOL)
Modicon Premium CPU All versionsAll versionsNo fix (EOL)
Remediation & Mitigation
0/8
Do now
0/2HARDENINGRestrict access to upload project files to the controller to authorized engineering personnel only (network access controls, role-based access)
WORKAROUNDDo not use PLC Simulator for EcoStruxure Control Expert and Process Expert in production environments; use only in isolated test/development systems
Schedule — requires maintenance window
0/5Patching may require device reboot — plan for process interruption
HOTFIXUpdate Modicon M580 CPU to firmware version SV4.10 or later
HOTFIXUpdate Modicon M580 CPU Safety (BMEP58*S, BMEH58*S) to firmware version SV4.21 or later and EcoStruxure Control Expert to V16.0 HF001 or later
HOTFIXUpdate Modicon M340 CPU to firmware version 3.50 or later
HOTFIXUpdate Modicon MC80 to firmware version SV1.90 or later
HOTFIXUpdate Modicon Momentum CPU to firmware version V2.6 or later
Mitigations - no patch available
0/1The following products have reached End of Life with no planned fix: Legacy Modicon Premium and Quantum All versions, Modicon Premium CPU All versions. Apply the following compensating controls:
HARDENINGDisable or isolate legacy Modicon Premium, Quantum, and Modicon Premium CPU controllers from network access where possible, and monitor for suspicious project file uploads
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