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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
2024-08-13
Original CVE updated
2024-08-13
Advisory published
2024-08-13
Advisory updated
2024-08-13

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.

Official resources

CVE-2023-52425 was published on August 13, 2024, with CISA ICS advisory ICSA-24-228-06 issued the same date. The vulnerability affects libexpat through version 2.5.0 and has been confirmed to impact Siemens SINEC NMS.