PatchSiren

PatchSiren cyber security CVE debrief

CVE-2025-26389 Siemens CVE debrief

CVE-2025-26389 is a critical Siemens OZW Web Servers vulnerability affecting OZW672 and OZW772. According to the CISA CSAF advisory and Siemens references, the web service does not sanitize input parameters for the `exportDiagramPage` endpoint, which can allow an unauthenticated remote attacker to execute arbitrary code with root privileges. Because the attack is network-based and requires no user interaction or authentication, this issue should be treated as urgent for exposed industrial environments.

Vendor
Siemens
Product
OZW672
CVSS
CRITICAL 10
CISA KEV
Not listed in stored evidence
Original CVE published
2025-05-13
Original CVE updated
2025-05-13
Advisory published
2025-05-13
Advisory updated
2025-05-13

Who should care

OT/ICS operators and security teams running Siemens OZW672 or OZW772, especially any environment where the web service is reachable from untrusted networks. System integrators, asset owners, and defenders responsible for patching or segmenting Siemens building or industrial control assets should prioritize this advisory.

Technical summary

The advisory describes an input-sanitization failure in the `exportDiagramPage` endpoint of affected Siemens web services. The resulting impact is unauthenticated remote code execution with root privileges. The supplied CVSS vector is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H, indicating a high-severity network-reachable issue with no privileges required and no user interaction needed.

Defensive priority

Immediate. This is a critical, network-reachable RCE affecting OT-facing web services, with no authentication required and full confidentiality, integrity, and availability impact stated in the advisory.

Recommended defensive actions

  • Apply the vendor fix and update affected devices to V8.0 or later, as specified in the Siemens remediation guidance.
  • Inventory Siemens OZW672 and OZW772 assets and confirm whether the affected web service is deployed or exposed.
  • Restrict network access to the web interface and place affected devices behind appropriate segmentation and access controls.
  • Review the Siemens and CISA advisory references for product-specific remediation guidance before maintenance windows.
  • Validate remediation after patching by confirming the device reports the intended version and that the web service exposure is reduced.

Evidence notes

The debrief is based on the supplied CISA CSAF source item for ICSA-25-135-10 and the embedded Siemens references. The source explicitly states that unsanitized input parameters in `exportDiagramPage` can enable an unauthenticated remote attacker to execute arbitrary code with root privileges. Product scope, remediation version, and severity vector were taken from the provided corpus only.

Sources and references

Verified primary and authoritative sources

  • CVE-2025-26389 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2025-26389

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

  • CVE-2025-26389 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2025-26389

    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-25-135-10.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/csaf/ssa-047424.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/html/ssa-047424.html

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-25-135-10

    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.