HighCVE-2023-32736

    Siemens SIMATIC S7-PLCSIM V16: Deserialization of Untrusted Data (CVE-2023-32736)

    Published Sources: CVE.org, Siemens ProductCERT

    What is affected, what to do

    A vulnerability has been identified in SIMATIC S7-PLCSIM V16 (All versions), SIMATIC S7-PLCSIM V17 (All versions), SIMATIC STEP 7 Safety V16 (All versions), SIMATIC STEP 7 Safety V17 (All versions < V17 Update 8), SIMATIC STEP 7 Safety V18 (All versions < V18 Update 5), SIMATIC STEP 7 V16 (All versions), SIMATIC STEP 7 V17 (All versions < V17 Update 8), SIMATIC STEP 7 V18 (All versions < V18 Update 5), SIMATIC WinCC Unified V16 (All versions), SIMATIC WinCC Unified V17 (All versions < V17 Update 8), SIMATIC WinCC Unified V18 (All versions < V18 SP5), SIMATIC WinCC V16 (All versions), SIMATIC WinCC V17 (All versions < V17 Update 8), SIMATIC WinCC V18 (All versions < V18 SP5), SIMOCODE ES V16 (All versions), SIMOCODE ES V17 (All versions < V17 Update 8), SIMOCODE ES V18 (All versions), SIMOTION SCOUT TIA V5.4 SP1 (All versions), SIMOTION SCOUT TIA V5.4 SP3 (All versions), SIMOTION SCOUT TIA V5.5 SP1 (All versions), SINAMICS Startdrive V16 (All versions), SINAMICS Startdrive V17 (All versions), SINAMICS Startdrive V18 (All versions), SIRIUS Safety ES V17 (TIA Portal) (All versions < V17 Update 8), SIRIUS Safety ES V18 (TIA Portal) (All versions), SIRIUS Soft Starter ES V17 (TIA Portal) (All versions < V17 Update 8), SIRIUS Soft Starter ES V18 (TIA Portal) (All versions), TIA Portal Cloud V16 (All versions), TIA Portal Cloud V17 (All versions < V4.6.0.1), TIA Portal Cloud V18 (All versions < V4.6.1.0). Affected products do not properly sanitize user-controllable input when parsing user settings.

    The available sources name no fixed version. Check the vendor guidance in the references below.

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    7.3

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    7.3

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: CVE.org, Siemens ProductCERT

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 12.4

    Show all metrics
    Severity
    High
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    44.54 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    7.3 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    7.3
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    7.0
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    0.2 %
    Low — model estimates < 1% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    12.4
    Elevated — this CVE ranks above at least 10% of all CVEs scored today.
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CISA assessment (SSVC)
    Exploitation: none known · not automatable · Technical impact: total
    Source: CISA Vulnrichment, as of 2 December 2024
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-502

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    A vulnerability has been identified in SIMATIC S7-PLCSIM V16 (All versions), SIMATIC S7-PLCSIM V17 (All versions), SIMATIC STEP 7 Safety V16 (All versions), SIMATIC STEP 7 Safety V17 (All versions < V17 Update 8), SIMATIC STEP 7 Safety V18 (All versions < V18 Update 5), SIMATIC STEP 7 V16 (All versions), SIMATIC STEP 7 V17 (All versions < V17 Update 8), SIMATIC STEP 7 V18 (All versions < V18 Update 5), SIMATIC WinCC Unified V16 (All versions), SIMATIC WinCC Unified V17 (All versions < V17 Update 8), SIMATIC WinCC Unified V18 (All versions < V18 SP5), SIMATIC WinCC V16 (All versions), SIMATIC WinCC V17 (All versions < V17 Update 8), SIMATIC WinCC V18 (All versions < V18 SP5), SIMOCODE ES V16 (All versions), SIMOCODE ES V17 (All versions < V17 Update 8), SIMOCODE ES V18 (All versions), SIMOTION SCOUT TIA V5.4 SP1 (All versions), SIMOTION SCOUT TIA V5.4 SP3 (All versions), SIMOTION SCOUT TIA V5.5 SP1 (All versions), SINAMICS Startdrive V16 (All versions), SINAMICS Startdrive V17 (All versions), SINAMICS Startdrive V18 (All versions), SIRIUS Safety ES V17 (TIA Portal) (All versions < V17 Update 8), SIRIUS Safety ES V18 (TIA Portal) (All versions), SIRIUS Soft Starter ES V17 (TIA Portal) (All versions < V17 Update 8), SIRIUS Soft Starter ES V18 (TIA Portal) (All versions), TIA Portal Cloud V16 (All versions), TIA Portal Cloud V17 (All versions < V4.6.0.1), TIA Portal Cloud V18 (All versions < V4.6.1.0). Affected products do not properly sanitize user-controllable input when parsing user settings. This could allow an attacker to cause a type confusion and execute arbitrary code within the affected application.

    Source: NVD (NIST), siemens_advisory, cvelistv5

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    SiemensSIMATIC S7-PLCSIM V16
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    SiemensSIMATIC S7-PLCSIM V17
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    SiemensSIMATIC STEP 7 Safety V16
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    SiemensSIMATIC STEP 7 Safety V17
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    SiemensSIMATIC STEP 7 Safety V18
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    SiemensSIMATIC STEP 7 V16
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    SiemensSIMATIC STEP 7 V17
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    SiemensSIMATIC STEP 7 V18
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    SiemensSIMATIC WinCC Unified V16
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    SiemensSIMATIC WinCC Unified V17
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    SiemensSIMATIC WinCC Unified V18
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    SiemensSIMATIC WinCC V16
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    SiemensSIMATIC WinCC V17
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    SiemensSIMATIC WinCC V18
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    SiemensSIMOCODE ES V16
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    SiemensSIMOCODE ES V17
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    SiemensSIMOCODE ES V18
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    SiemensSIMOTION SCOUT TIA V5.4 SP1
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    SiemensSIMOTION SCOUT TIA V5.4 SP3
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    SiemensSIMOTION SCOUT TIA V5.5 SP1
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    SiemensSINAMICS Startdrive V16
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    SiemensSINAMICS Startdrive V17
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    SiemensSINAMICS Startdrive V18
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    SiemensSIRIUS Safety ES V17 (TIA Portal)
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    SiemensSIRIUS Safety ES V18 (TIA Portal)
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    SiemensSIRIUS Soft Starter ES V17 (TIA Portal)
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    SiemensSIRIUS Soft Starter ES V18 (TIA Portal)
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    SiemensTIA Portal Cloud V16
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    SiemensTIA Portal Cloud V17
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    SiemensTIA Portal Cloud V18
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    Vendors and products

    Weakness classes (CWE)

    • CWE-502Deserialization of Untrusted Data

      Base

      The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

      Entry at MITRE CWE-502

    References & sources

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    <a href="https://intel.neosec.eu/en/cve/CVE-2023-32736"><img src="https://intel.neosec.eu/badge/cve/CVE-2023-32736.svg?lang=en" alt="CVE-2023-32736 – NEOSEC Intel" height="20"></a>