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CVE-2024-5594 Siemens CVE debrief

CVE-2024-5594 affects Siemens SINEMA Remote Connect Server and was publicly disclosed on 2025-03-11 in Siemens/CISA advisories. The issue is in control-channel message handling: messages containing nonprintable characters should be refused, but the advisory notes that a malicious OpenVPN peer could otherwise cause garbage to be written to the OpenVPN log or trigger high CPU load. Siemens provides a fixed release recommendation: update to V3.2 SP3 or later.

Vendor
Siemens
Product
SINEMA Remote Connect Server
CVSS
MEDIUM 5.4
CISA KEV
Not listed in stored evidence
Original CVE published
2024-11-12
Original CVE updated
2025-05-06
Advisory published
2024-11-12
Advisory updated
2025-05-06

Who should care

Organizations running Siemens SINEMA Remote Connect Server, especially teams responsible for remote access, OT network monitoring, and patching of externally reachable VPN/control-channel components. Operators should care even though the severity is medium, because the issue can impact logging integrity and availability.

Technical summary

The advisory describes a validation weakness in control-channel message handling. Nonprintable characters are supposed to be rejected, but malformed input from a malicious OpenVPN peer can be accepted far enough to affect logging and CPU usage. The published CVSS vector is AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L, indicating network reachability, low privileges, no user interaction, and limited integrity/availability impact.

Defensive priority

Medium priority. Remediate as part of routine OT remote-access hardening, and elevate priority if the affected server is internet-reachable, broadly exposed to partner connectivity, or operationally sensitive to logging/CPU degradation.

Recommended defensive actions

  • Upgrade Siemens SINEMA Remote Connect Server to V3.2 SP3 or later.
  • Review exposure of the remote-access/control-channel service and restrict access to only required peers.
  • Monitor for abnormal log content and unexpected CPU spikes on affected systems until remediation is complete.
  • Track Siemens and CISA advisories for any follow-up guidance or product-specific mitigations.

Evidence notes

Primary evidence comes from the CISA CSAF advisory ICSA-25-072-02 and Siemens' linked security advisory resources. The supplied description explicitly states: 'control channel: refuse control channel messages with nonprintable characters in them' and notes that a malicious OpenVPN peer can send garbage to the OpenVPN log or cause high CPU load. The remediated version is listed by Siemens as V3.2 SP3 or later. The provided CVSS vector is CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L/E:U/RL:O/RC:C.

Sources and references

Verified primary and authoritative sources

  • CVE-2024-5594 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2024-5594

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2024-5594 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2024-5594

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2025/icsa-25-072-02.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/csaf/ssa-073066.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/html/ssa-073066.html

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-25-072-02

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/uscert/ics/alerts/ICS-ALERT-10-301-01

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/resources-tools/resources/ics-recommended-practices

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/topics/industrial-control-systems

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://us-cert.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf

    Reference

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.