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PatchSiren cyber security CVE debrief

CVE-2024-35813 Siemens CVE debrief

A vulnerability in the Linux kernel's MMC (MultiMediaCard) core subsystem could allow a local attacker to cause a denial of service condition. The flaw exists in the close-ended FFU (Field Firmware Update) code path where an array access using `prev_idata = idatas[i - 1]` occurs without validating that the iterator `i` is greater than zero. This missing bounds check could result in a negative array index access. The vulnerability was introduced in commit 4d0c8d0aef63 (mmc: core: Use mrq.sbc in close-ended ffu). Siemens has identified this vulnerability as affecting the GNU/Linux subsystem of the SIMATIC S7-1500 TM MFP industrial control system. No patch is currently available from the vendor.

Vendor
Siemens
Product
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2024-05-17
Original CVE updated
2026-08-04
Advisory published
2024-05-17
Advisory updated
2026-08-04

Who should care

Organizations operating Siemens SIMATIC S7-1500 TM MFP systems with the GNU/Linux subsystem enabled, industrial control system operators, OT security teams, and Linux kernel maintainers deploying MMC/SD card support in embedded or industrial environments.

Technical summary

The vulnerability is an off-by-one style bounds checking issue in the Linux kernel's MMC core subsystem. When processing close-ended FFU operations, the code assigns `prev_idata = idatas[i - 1]` without first verifying that `i > 0`. On the first iteration where `i == 0`, this results in accessing `idatas[-1]`, which is undefined behavior and typically causes an out-of-bounds memory access. This can lead to kernel crashes or memory corruption, resulting in denial of service. The fix involves adding a simple bounds check before the array access.

Defensive priority

medium

Recommended defensive actions

  • Restrict interactive shell access to the GNU/Linux subsystem to trusted personnel only
  • Only build and run applications from trusted sources
  • Monitor for vendor security updates from Siemens
  • Apply defense-in-depth strategies for industrial control systems per CISA guidance

Evidence notes

The vulnerability description is sourced from the Linux kernel commit message and CISA ICS advisory ICSA-24-102-01. The affected product identification comes from the CSAF product tree with high confidence. The CVSS 3.1 vector AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H indicates local attack vector with low attack complexity, low privileges required, and high availability impact.

Sources and references

Verified primary and authoritative sources

  • CVE-2024-35813 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2024-35813

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

  • CVE-2024-35813 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2024-35813

    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-24-102-01.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/csaf/ssa-265688.json

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://cert-portal.siemens.com/productcert/html/ssa-265688.html

    Reference

  • Source reference

    Unverified legacy reference

    URL: https://www.cisa.gov/news-events/ics-advisories/icsa-24-102-01

    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.