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CVE-2024-53042 Siemens CVE debrief

A Linux kernel vulnerability in the IPv4 IP tunnel subsystem where `ip_tunnel_init_flow()` is called without holding the RCU read lock, triggering a suspicious RCU usage warning. The issue occurs when code paths traverse RCU-protected lists in non-reader sections. The fix replaces `l3mdev_master_upper_ifindex_by_index_rcu()` with `l3mdev_master_upper_ifindex_by_index()`, which properly acquires the RCU read lock. This vulnerability affects Siemens SIMATIC S7-1500 TM MFP industrial control systems running the GNU/Linux subsystem.

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 industrial control systems with the GNU/Linux subsystem enabled; OT security teams managing Linux-based industrial devices; kernel maintainers and network stack developers

Technical summary

The vulnerability exists in `ip_tunnel_init_flow()` within the Linux kernel's IPv4 IP tunnel implementation. The function calls `l3mdev_master_upper_ifindex_by_index_rcu()` without ensuring the RCU read lock is held, violating RCU usage conventions. When CONFIG_PROVE_RCU or similar debugging is enabled, this triggers a suspicious RCU usage warning indicating RCU-list traversal in a non-reader section. The resolution substitutes `l3mdev_master_upper_ifindex_by_index()`, which internally acquires `rcu_read_lock()` before accessing RCU-protected data structures. This is a correctness fix that prevents potential use-after-free or data corruption scenarios in network device layer operations.

Defensive priority

medium

Recommended defensive actions

  • Apply kernel updates from Siemens when available per advisory guidance
  • Restrict interactive shell access to the GNU/Linux subsystem to trusted personnel only
  • Build and run applications only from trusted sources
  • Monitor for anomalous network tunnel behavior or kernel warnings
  • Review CISA ICS recommended practices for defense-in-depth strategies

Evidence notes

The vulnerability was resolved in the Linux kernel by modifying `ip_tunnel_init_flow()` to use the non-RCU variant of the function that internally manages RCU read lock acquisition. The warning was observed in kernel version 6.12.0-rc3 with debug locks enabled, showing RCU-list traversal in non-reader section at net/core/dev.c:876 while holding rtnl_mutex.

Sources and references

Verified primary and authoritative sources

  • CVE-2024-53042 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2024-53042

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

  • CVE-2024-53042 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2024-53042

    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.