PatchSiren

PatchSiren cyber security CVE debrief

CVE-2023-6121 Siemens CVE debrief

CVE-2023-6121 is a Linux kernel NVMe-oF/TCP issue that can expose kernel memory contents through an out-of-bounds read. According to the supplied source description, a crafted TCP packet may trigger a heap-based buffer overflow that results in kmalloc data being printed and potentially leaked to the kernel ring buffer (dmesg). NVD classifies the weakness as CWE-125 and rates it CVSS 4.3 (AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).

Vendor
Siemens
Product
RUGGEDCOM RST2428P (6GK6242-6PA00)
CVSS
MEDIUM 4.3
CISA KEV
Not listed in stored evidence
Original CVE published
2025-08-12
Original CVE updated
2026-02-25
Advisory published
2025-08-12
Advisory updated
2026-02-25

Who should care

Linux administrators and platform teams running NVMe-over-Fabrics over TCP, especially on distributions or appliances that ship affected Linux kernel builds. Based on the source corpus, Red Hat Enterprise Linux 6.0, 7.0, 8.0, and 9.0 are listed as vulnerable CPE criteria, and downstream vendors also reference the issue in their advisories.

Technical summary

The vulnerability is an out-of-bounds read in the NVMe-oF/TCP subsystem of the Linux kernel. The supplied description says a remote attacker may send a crafted TCP packet that can trigger a heap-based buffer overflow, causing kmalloc data to be printed and potentially leaked to dmesg. NVD maps the issue to CWE-125 and gives it a network-reachable CVSS vector of AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N, indicating low-privilege access is required and the primary impact is limited confidentiality leakage.

Defensive priority

Medium. The issue is network-triggerable and can expose kernel memory contents, but the supplied CVSS vector indicates limited confidentiality impact and no integrity or availability impact. Prioritize systems that expose NVMe-oF/TCP services or rely on kernel builds identified by vendor advisories.

Recommended defensive actions

  • Apply vendor kernel updates or errata referenced for CVE-2023-6121 as soon as practical.
  • Prioritize externally reachable NVMe-oF/TCP hosts and storage nodes for patching.
  • Review downstream vendor advisories and issue tracking referenced in the source corpus to confirm the exact fixed builds for your distribution.
  • If immediate patching is not possible, reduce exposure of NVMe-oF/TCP endpoints to only trusted management or storage networks.
  • Validate that logging and monitoring coverage includes unexpected kernel-ring-buffer messages on affected systems.

Evidence notes

All claims are grounded in the supplied NVD-derived source item and its listed references. The source description states the issue is an out-of-bounds read in Linux NVMe-oF/TCP that may leak kmalloc data into dmesg. The metadata lists CWE-125, CVSS vector AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N, and vulnerable CPE criteria for Red Hat Enterprise Linux 6.0, 7.0, 8.0, and 9.0. The reference set also includes Red Hat errata, a Red Hat bug tracker entry, Debian LTS, and Siemens advisories, showing downstream vendor handling in the corpus. Published date used: 2023-11-16; modified date used: 2026-05-12.

Sources and references

Verified primary and authoritative sources

  • CVE-2023-6121 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2023-6121

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

  • CVE-2023-6121 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2023-6121

    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-25-226-15.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/csaf/ssa-613116.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/html/ssa-613116.html

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-25-226-15

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/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://www.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.