HighCVE-2021-40359

    Siemens SIMATIC: Path Traversal (CVE-2021-40359)

    Published Sources: Siemens ProductCERT, CVE.org

    What is affected, what to do

    A vulnerability has been identified in OpenPCS 7 V8.2 (All versions), OpenPCS 7 V9.0 (All versions < V9.0 Upd4), OpenPCS 7 V9.1 (All versions), SIMATIC BATCH V8.2 (All versions), SIMATIC BATCH V9.0 (All versions), SIMATIC BATCH V9.1 (All versions), SIMATIC NET PC Software V14 (All versions), SIMATIC NET PC Software V15 (All versions), SIMATIC NET PC Software V16 (All versions < V16 Update 6), SIMATIC NET PC Software V17 (All versions < V17 SP1), SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3 UC04), SIMATIC PCS 7 V9.1 (All versions < V9.1 SP1), SIMATIC Route Control V8.2 (All versions), SIMATIC Route Control V9.0 (All versions), SIMATIC Route Control V9.1 (All versions), SIMATIC WinCC V15 and earlier (All versions < V15 SP1 Update 7), SIMATIC WinCC V16 (All versions < V16 Update 5), SIMATIC WinCC V17 (All versions < V17 Update 2), SIMATIC WinCC V7.4 (All versions < V7.4 SP1 Update 19), SIMATIC WinCC V7.5 (All versions < V7.5 SP2 Update 5). When downloading files, the affected systems do not properly neutralize special elements within the pathname.

    Update simaticpcs_7 to version 9.1.

    Affected
    • Siemens OpenPCS 7 V8.2 eq All versions..All versions
    • Siemens OpenPCS 7 V9.0 eq All versions < V9.0 Upd4..All versions < V9.0 Upd4
    • Siemens OpenPCS 7 V9.1 eq All versions..All versions
    • Siemens SIMATIC BATCH V8.2 eq All versions..All versions
    • Siemens SIMATIC BATCH V9.0 eq All versions..All versions
    • Siemens SIMATIC BATCH V9.1 eq All versions..All versions
    • Siemens SIMATIC NET PC Software V14 eq All versions..All versions
    • Siemens SIMATIC NET PC Software V15 eq All versions..All versions
    • Siemens SIMATIC NET PC Software V16 eq All versions < V16 Update 6..All versions < V16 Update 6
    • Siemens SIMATIC NET PC Software V17 eq All versions < V17 SP1..All versions < V17 SP1
    • Siemens SIMATIC PCS 7 V8.2 eq All versions..All versions
    • Siemens SIMATIC PCS 7 V9.0 eq All versions < V9.0 SP3 UC04..All versions < V9.0 SP3 UC04
    • Siemens SIMATIC PCS 7 V9.1 eq All versions < V9.1 SP1..All versions < V9.1 SP1
    • Siemens SIMATIC Route Control V8.2 eq All versions..All versions
    • Siemens SIMATIC Route Control V9.0 eq All versions..All versions
    • Siemens SIMATIC Route Control V9.1 eq All versions..All versions
    • Siemens SIMATIC WinCC V15 and earlier eq All versions < V15 SP1 Update 7..All versions < V15 SP1 Update 7
    • Siemens SIMATIC WinCC V16 eq All versions < V16 Update 5..All versions < V16 Update 5
    • Siemens SIMATIC WinCC V17 eq All versions < V17 Update 2..All versions < V17 Update 2
    • Siemens SIMATIC WinCC V7.4 eq All versions < V7.4 SP1 Update 19..All versions < V7.4 SP1 Update 19
    • Siemens SIMATIC WinCC V7.5 eq All versions < V7.5 SP2 Update 5..All versions < V7.5 SP2 Update 5

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    Metrics

    7.7

    Priority

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

    Source: Vendor (CNA), CVSS v3

    7.7

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: Siemens ProductCERT, CVE.org

    1.2 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 67.4

    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
    74.86 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
    7.7 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
    7.7
    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
    1.2 %
    Moderate — model estimates 1-10% 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
    67.4
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    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
    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-22

    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 OpenPCS 7 V8.2 (All versions), OpenPCS 7 V9.0 (All versions < V9.0 Upd4), OpenPCS 7 V9.1 (All versions), SIMATIC BATCH V8.2 (All versions), SIMATIC BATCH V9.0 (All versions), SIMATIC BATCH V9.1 (All versions), SIMATIC NET PC Software V14 (All versions), SIMATIC NET PC Software V15 (All versions), SIMATIC NET PC Software V16 (All versions < V16 Update 6), SIMATIC NET PC Software V17 (All versions < V17 SP1), SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3 UC04), SIMATIC PCS 7 V9.1 (All versions < V9.1 SP1), SIMATIC Route Control V8.2 (All versions), SIMATIC Route Control V9.0 (All versions), SIMATIC Route Control V9.1 (All versions), SIMATIC WinCC V15 and earlier (All versions < V15 SP1 Update 7), SIMATIC WinCC V16 (All versions < V16 Update 5), SIMATIC WinCC V17 (All versions < V17 Update 2), SIMATIC WinCC V7.4 (All versions < V7.4 SP1 Update 19), SIMATIC WinCC V7.5 (All versions < V7.5 SP2 Update 5). When downloading files, the affected systems do not properly neutralize special elements within the pathname. An attacker could then cause the pathname to resolve to a location outside of the restricted directory on the server and read unexpected critical files.

    Source: siemens_advisory, NVD (NIST), 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
    SiemensOpenPCS 7 V8.2
    • All versions
    • —
    SiemensOpenPCS 7 V9.0
    • All versions < V9.0 Upd4
    • —
    SiemensOpenPCS 7 V9.1
    • All versions
    • —
    SiemensSIMATIC BATCH V8.2
    • All versions
    • —
    SiemensSIMATIC BATCH V9.0
    • All versions
    • —
    SiemensSIMATIC BATCH V9.1
    • All versions
    • —
    SiemensSIMATIC NET PC Software V14
    • All versions
    • —
    SiemensSIMATIC NET PC Software V15
    • All versions
    • —
    SiemensSIMATIC NET PC Software V16
    • All versions < V16 Update 6
    • —
    SiemensSIMATIC NET PC Software V17
    • All versions < V17 SP1
    • —
    SiemensSIMATIC PCS 7 V8.2
    • All versions
    • —
    SiemensSIMATIC PCS 7 V9.0
    • All versions < V9.0 SP3 UC04
    • —
    SiemensSIMATIC PCS 7 V9.1
    • All versions < V9.1 SP1
    • —
    SiemensSIMATIC Route Control V8.2
    • All versions
    • —
    SiemensSIMATIC Route Control V9.0
    • All versions
    • —
    SiemensSIMATIC Route Control V9.1
    • All versions
    • —
    SiemensSIMATIC WinCC V15 and earlier
    • All versions < V15 SP1 Update 7
    • —
    SiemensSIMATIC WinCC V16
    • All versions < V16 Update 5
    • —
    SiemensSIMATIC WinCC V17
    • All versions < V17 Update 2
    • —
    SiemensSIMATIC WinCC V7.4
    • All versions < V7.4 SP1 Update 19
    • —
    SiemensSIMATIC WinCC V7.5
    • All versions < V7.5 SP2 Update 5
    • —
    siemenssimatic_batch
    • 9.0
    • 8.2
    • 9.1
    • —
    • —
    • —
    siemenssimatic_net_pc
    • 15
    • 17
    • 14
    • 16
    • —
    • —
    • —
    • —
    siemenssimatic_route_control
    • 9.1
    • 8.2
    • 9.0
    • —
    • —
    • —
    siemenssimatic_wincc
    • 16
    • 7.5
    • 17
    • 15
    • ≤ 7.4
    • —
    • —
    • —
    • —
    • —
    siemenssimaticpcs_7
    • 9.0 – < 9.1
    • ≤ 8.2
    • 9.1
    • 9.1
    • —
    • —

    Vendors and products

    Weakness classes (CWE)

    • CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

      Base

      The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

      Entry at MITRE CWE-22

    References & sources

    Linked advisories

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    Badge preview for CVE-2021-40359
    <a href="https://intel.neosec.eu/en/cve/CVE-2021-40359"><img src="https://intel.neosec.eu/badge/cve/CVE-2021-40359.svg?lang=en" alt="CVE-2021-40359 – NEOSEC Intel" height="20"></a>