PatchSiren

PatchSiren cyber security CVE debrief

CVE-2024-42076 Siemens CVE debrief

CVE-2024-42076 is a vulnerability in the Linux kernel's Controller Area Network (CAN) J1939 protocol implementation, specifically within the j1939_send_one() function. The issue involves unused data in this function, which could lead to information disclosure or undefined behavior. The vulnerability has been assigned a CVSS score of 5.5 (MEDIUM severity). Siemens has identified this CVE as affecting certain industrial networking products running SINEC OS, including the RUGGEDCOM RST2428P and SCALANCE X-family switches. However, the CISA advisory marks the impact assessment as 'Misinformed,' suggesting the actual risk to these products may differ from initial assessments. The vulnerability was published on August 12, 2025, and last modified on February 25, 2026, with the most recent update reflecting CISA republication based on Siemens ProductCERT advisory SSA-355557.

Vendor
Siemens
Product
RUGGEDCOM RST2428P (6GK6242-6PA00)
CVSS
MEDIUM 5.5
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

Organizations operating Siemens RUGGEDCOM RST2428P switches, SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family, or SCALANCE XCM-/XRM-/XCH-/XRH-300 family devices in industrial control environments. System administrators managing CAN/J1939 networks in transportation, manufacturing, and critical infrastructure sectors should monitor vendor guidance for clarification on actual product impact given the 'Misinformed' classification in the advisory.

Technical summary

The vulnerability exists in the Linux kernel's net/can/j1939/ implementation. The j1939_send_one() function contains unused data that may not be properly initialized or cleared before transmission, potentially leading to information disclosure of kernel memory contents. The J1939 protocol is used in heavy-duty vehicles and industrial applications for CAN bus communication. While the CVSS base score is 5.5 (MEDIUM), the CISA advisory marks the impact as 'Misinformed,' indicating the actual security impact on Siemens products may require re-evaluation. The vulnerability affects Siemens industrial networking products utilizing SINEC OS with the vulnerable kernel component.

Defensive priority

medium

Recommended defensive actions

  • Review Siemens ProductCERT advisory SSA-355557 for current product impact assessment
  • Verify SINEC OS version and kernel CAN/J1939 subsystem configuration on affected Siemens devices
  • Apply vendor-provided firmware updates when available per Siemens security advisory
  • Monitor CISA ICS advisories for updates to impact classification
  • Implement network segmentation for CAN/J1939 traffic in industrial control environments
  • Follow CISA ICS recommended practices for defense-in-depth strategies

Evidence notes

CVE published 2025-08-12; modified 2026-02-25. CISA advisory ICSA-25-226-07 identifies Siemens as vendor. Impact marked 'Misinformed' in source. Advisory updated 2026-02-25 based on Siemens SSA-355557.

Official resources

public