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PatchSiren cyber security CVE debrief

CVE-2023-46589 Siemens CVE debrief

CVE-2023-46589 is an improper input validation vulnerability in Apache Tomcat that affects multiple versions across the 8.5, 9.0, 10.1, and 11.0 release lines. The vulnerability stems from incorrect parsing of HTTP trailer headers, where a trailer header exceeding the configured size limit can cause Tomcat to misinterpret a single HTTP request as multiple separate requests. This parsing error creates conditions for HTTP request smuggling attacks when Tomcat is deployed behind a reverse proxy, potentially allowing attackers to bypass security controls, access unauthorized resources, or poison web caches. The vulnerability carries a HIGH severity CVSS 3.1 score of 7.5, reflecting its network attack vector, low attack complexity, and no required privileges or user interaction. Siemens SINEC NMS is identified as an affected product incorporating vulnerable Tomcat components. The issue was published on August 13, 2024, with coordinated disclosure through CISA and Siemens security advisories. Apache has released patched versions that correct the trailer header parsing logic.

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 Apache Tomcat behind reverse proxies, particularly in industrial control system environments using Siemens SINEC NMS for network management. Security teams responsible for web application firewall rule tuning, reverse proxy configuration, and ICS/OT security posture should prioritize assessment. DevOps and platform engineering teams managing containerized or traditional Tomcat deployments should evaluate patch applicability. Compliance teams tracking CVE remediation for critical infrastructure should note the CISA ICS advisory classification.

Technical summary

The vulnerability exists in Tomcat's HTTP/1.1 trailer header parsing implementation. When processing chunked transfer-encoded requests with trailing headers, Tomcat fails to properly validate header size limits during the trailer parsing phase. An oversized trailer header can trigger parsing state confusion, causing the remainder of the request body to be interpreted as the start of a subsequent HTTP request. This desynchronization between the reverse proxy's view of request boundaries and Tomcat's internal request parsing enables classic HTTP request smuggling attacks. The attack requires the reverse proxy to forward requests without re-chunking or normalizing the transfer encoding, and for the proxy to have different header size limits than the backend Tomcat server. Successful exploitation could allow cache poisoning, credential hijacking, or unauthorized access to protected resources.

Defensive priority

HIGH

Recommended defensive actions

  • Upgrade Apache Tomcat to patched versions: 11.0.0-M11 or later, 10.1.16 or later, 9.0.83 or later, or 8.5.96 or later
  • For Siemens SINEC NMS deployments, update to version 3.0 or later
  • Review reverse proxy configurations for request smuggling mitigations including consistent header size limits
  • Monitor for anomalous HTTP request patterns that may indicate smuggling attempts
  • Validate that trailer header size limits are enforced consistently across all proxy layers
  • Apply defense-in-depth controls per CISA ICS recommended practices for industrial control system environments

Evidence notes

Vulnerability description and affected version ranges derived from official CVE record and CISA ICS advisory ICSA-24-228-06. Siemens SINEC NMS product association confirmed through CSAF product tree vendor field. Remediation guidance sourced from CISA advisory remediation section specifying update to V3.0 or later. CVSS score and severity from official CVE metadata.

Sources and references

Verified primary and authoritative sources

  • CVE-2023-46589 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2023-46589

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

  • CVE-2023-46589 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2023-46589

    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.