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PatchSiren cyber security CVE debrief

CVE-2023-52425 Siemens CVE debrief

CVE-2023-52425 is a denial-of-service vulnerability in libexpat through version 2.5.0, caused by excessive resource consumption when processing large tokens requiring multiple buffer fills and repeated full reparsings. The vulnerability was published on August 13, 2024, with a CVSS 3.1 score of 7.5 (HIGH). Siemens SINEC NMS is affected, with remediation available by updating to version 3.0 or later. The vulnerability is not listed in CISA's Known Exploited Vulnerabilities catalog.

Vendor
Siemens
Product
SINEC NMS
CVSS
HIGH 7.5
CISA KEV
Not listed in stored evidence
Original CVE published
2023-12-12
Original CVE updated
2025-08-12
Advisory published
2023-12-12
Advisory updated
2025-08-12

Who should care

Organizations running Siemens SINEC NMS, developers using libexpat for XML parsing in network-accessible applications, and operators of industrial control systems that may process untrusted XML input should prioritize remediation.

Technical summary

The vulnerability exists in libexpat's handling of large tokens that require multiple buffer fills. When such tokens are processed, the parser performs many full reparsings, leading to excessive resource consumption and potential denial of service. The attack vector is network-accessible with low complexity and no authentication required.

Defensive priority

HIGH

Recommended defensive actions

  • Update Siemens SINEC NMS to version 3.0 or later per vendor guidance
  • Review XML parsing implementations for libexpat usage and upgrade to patched versions
  • Monitor network-accessible services that may parse untrusted XML input
  • Apply defense-in-depth controls for industrial control systems per CISA recommended practices
  • Validate input size limits for XML documents processed by affected systems

Evidence notes

The vulnerability description is sourced from CISA CSAF advisory ICSA-24-228-06, which references Siemens security advisory SSA-784301. The CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C indicates network attack vector with low attack complexity, no privileges required, and high availability impact.

Sources and references

Verified primary and authoritative sources

  • CVE-2023-52425 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2023-52425

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

  • CVE-2023-52425 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2023-52425

    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/2024/icsa-24-228-06.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/csaf/ssa-784301.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/html/ssa-784301.html

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-24-228-06

    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.