Siemens SIMATIC S7-1200 and S7-1500 CPU Families
Plan Patch9.3ICS-CERT ICSA-22-286-04Oct 11, 2022
Attack VectorLocal
Auth RequiredNone
ComplexityLow
User InteractionNone needed
Summary
Siemens SIMATIC S7-1200, S7-1500 CPUs and related products use a global private key shared across all devices in each product family to protect confidential configuration data and legacy PG/PC and HMI communication protocols. An attacker with access to a single CPU unit or backup memory card can perform an offline attack to extract this key and use it against all other devices in the same family. The extracted key enables decryption of configuration data or forgery of legitimate engineering and HMI messages. Siemens introduced individual password-based protection and TLS-encrypted communication in TIA Portal V17 and later as the modern replacement for this legacy protection scheme.
What this means
What could happen
An attacker with access to one CPU can extract the global private key used to protect all devices in that product family, then use it to decrypt confidential configuration data or impersonate engineering workstations and HMI systems to manipulate process logic.
Who's at risk
Manufacturing facilities and utilities using Siemens S7-1200 or S7-1500 PLCs for automation and process control. This includes SIMATIC Drive Controllers, ET 200SP Open Controllers, S7-PLCSIM Advanced simulation environments, and any organization relying on TIA Portal for engineering projects. Any facility with exposed CPU units, backup media, or unencrypted project files is at risk.
How it could be exploited
An attacker obtains a single CPU unit or a backup memory card/project file from a CPU and performs an offline cryptographic attack to extract the family-wide private key. Once extracted, the key can be used to decrypt configuration data from any other CPU in that family or to forge legitimate PG/PC and HMI communication messages to inject commands into the control system.
Prerequisites
- Physical or logical access to a CPU unit, backup memory card, or exported TIA Portal project file containing the encrypted key
- Offline computing capability to perform cryptographic analysis
- Knowledge of the legacy key protection algorithm
Low attack complexity (offline cryptanalysis)Affects all devices in a product family once key is extractedPhysical access or project file exposure enables complete compromiseLegacy protection mechanism cannot be considered secure by modern standardsNo patch available for SIMATIC ET 200SP Open Controller CPU 1515SP PC
Exploitability
Low exploit probability (EPSS 0.2%)
Affected products (7)
6 with fix1 EOL
ProductAffected VersionsFix Status
SIMATIC Drive Controller family<V2.9.22.9.2
SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants)<V21.921.9
SIMATIC S7-1200 CPU family (incl. SIPLUS variants)<V4.5.04.5.0
SIMATIC S7-1500 CPU family (incl. related ET200 CPUs and SIPLUS variants)<V2.9.22.9.2
SIMATIC S7-1500 Software Controller<V21.921.9
SIMATIC S7-PLCSIM Advanced<V4.04.0
SIMATIC ET 200SP Open Controller CPU 1515SP PC (incl. SIPLUS variants)All versionsNo fix (EOL)
Remediation & Mitigation
0/10
Do now
0/2WORKAROUNDConfigure all affected CPUs to 'Only allow PG/PC and HMI communication' to restrict legacy protocol access
HARDENINGRestrict physical access to CPU units, memory cards, and TIA Portal project files containing sensitive configuration data
Schedule — requires maintenance window
0/7Patching may require device reboot — plan for process interruption
SIMATIC Drive Controller family
HOTFIXUpdate SIMATIC Drive Controller family to version 2.9.2 or later
SIMATIC S7-1500 Software Controller
HOTFIXUpdate SIMATIC S7-1500 Software Controller to version 21.9 or later
SIMATIC S7-PLCSIM Advanced
HOTFIXUpdate SIMATIC S7-PLCSIM Advanced to version 4.0 or later
All products
HOTFIXUpdate SIMATIC ET 200SP Open Controller CPU 1515SP PC2 to version 21.9 or later
HOTFIXUpdate SIMATIC S7-1200 CPU family to version 4.5.0 or later
HOTFIXUpdate SIMATIC S7-1500 CPU family to version 2.9.2 or later
HOTFIXMigrate and redeploy TIA Portal projects to the updated firmware version after patching
Mitigations - no patch available
0/1SIMATIC ET 200SP Open Controller CPU 1515SP PC (incl. SIPLUS variants) has reached End of Life. The vendor will not release a patch. Apply the following compensating controls:
HARDENINGIsolate legacy PG/PC and HMI communication to trusted network segments with strict network access controls
CVEs (1)
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