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CVE-2024-42312 Siemens CVE debrief

CVE-2024-42312 is a Linux kernel vulnerability affecting the sysctl subsystem, specifically in how inode ownership fields (i_uid/i_gid) are initialized in /proc/sys inodes. The issue stems from incomplete initialization of these fields when set_ownership() callbacks skip setting them, potentially leading to use of uninitialized values. The vulnerability was resolved by ensuring i_uid/i_gid are always initialized in the sysfs core, with proper default values applied when ownership computation fails. Siemens has identified this as affecting the GNU/Linux subsystem of their SIMATIC S7-1500 TM MFP industrial control product. The vulnerability requires local access with low privileges and can result in high availability impact. No patch is currently available from Siemens; mitigation relies on access controls and trusted application practices.

Vendor
Siemens
Product
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2024-04-09
Original CVE updated
2026-05-14
Advisory published
2024-04-09
Advisory updated
2026-05-14

Who should care

Organizations operating Siemens SIMATIC S7-1500 TM MFP systems with enabled GNU/Linux subsystems, particularly in industrial automation and critical infrastructure environments. Security teams responsible for embedded Linux systems in OT/ICS environments should prioritize access controls until patches become available.

Technical summary

This vulnerability exists in the Linux kernel's sysctl implementation where i_uid and i_gid fields of /proc/sys inodes may remain uninitialized when set_ownership() callbacks skip setting them. The root cause was incomplete handling in net_ctl_set_ownership() which failed to apply default ownership values when computation of better values failed. The resolution moves initialization to the sysfs core, ensuring these fields are always set before set_ownership() is called. The vulnerability is classified as CWE-20 (Improper Input Validation) and has a CVSS 3.1 score of 5.5 (MEDIUM) with local attack vector, low attack complexity, low privileges required, and high availability impact.

Defensive priority

medium

Recommended defensive actions

  • Restrict interactive shell access to the GNU/Linux subsystem to trusted personnel only
  • Only build and execute applications from trusted sources
  • Monitor for Siemens security advisories regarding patch availability for SSA-265688
  • Apply defense-in-depth strategies for industrial control systems per CISA guidance
  • Review and implement ICS-CERT recommended practices for securing embedded Linux subsystems

Evidence notes

The vulnerability description indicates this is a kernel-level fix for uninitialized inode ownership fields in the sysctl/proc_sysctl subsystem. The fix ensures i_uid/i_gid are always initialized in the sysfs core, addressing a gap where net_ctl_set_ownership() failed to apply default values when ownership computation failed. Siemens has confirmed this affects their SIMATIC S7-1500 TM MFP product's GNU/Linux subsystem.

Sources and references

Verified primary and authoritative sources

  • CVE-2024-42312 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2024-42312

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

  • CVE-2024-42312 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2024-42312

    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.