PatchSiren cyber security CVE debrief

CVE-2024-43889 Siemens CVE debrief

CVE-2024-43889 is a divide-by-zero vulnerability in the Linux kernel's padata subsystem, specifically in the padata_mt_helper() function during system bootup. The flaw occurs when chunk_size is uninitialized and evaluates to zero, causing a potential crash condition. This vulnerability was published on August 12, 2025, and last modified on February 25, 2026. Siemens ProductCERT issued advisory SSA-355557 addressing third-party components in SINEC OS, which was subsequently republished by CISA as ICSA-25-226-07. The advisory underwent multiple revisions, with the most significant update on February 25, 2026, clarifying affected product configurations and removing rejected CVEs from the advisory. The vulnerability carries a MEDIUM severity CVSS score of 5.5. While the source advisory lists this CVE, the threat assessment categorizes the impact as 'Misinformed' for the referenced product IDs, suggesting potential documentation or categorization issues in the advisory's handling of this vulnerability. The affected products include Siemens industrial networking equipment running SINEC OS, specifically the RUGGEDCOM RST2428P and SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family devices. Organizations should consult the Siemens ProductCERT advisory for definitive patch guidance and affected product verification.

Vendor: Siemens
Product: RUGGEDCOM RST2428P (6GK6242-6PA00)
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 industrial networking equipment with SINEC OS, particularly RUGGEDCOM RST2428P and SCALANCE XC/XR series switches and routers. Critical infrastructure operators in energy, manufacturing, and transportation sectors using affected Siemens devices should prioritize verification against the Siemens ProductCERT advisory. Security teams responsible for OT/ICS asset management and patch coordination should monitor this advisory for definitive remediation guidance.

Technical summary

A divide-by-zero condition in padata_mt_helper() during kernel boot when chunk_size is uninitialized and zero. The vulnerability exists in the Linux kernel's parallel data processing subsystem (padata) and can trigger during system initialization. The flaw is categorized as MEDIUM severity with CVSS 5.5. Siemens has addressed this through third-party component updates in SINEC OS, with advisory SSA-355557 providing affected product guidance. The CISA advisory ICSA-25-226-07 republishes this information for U.S. critical infrastructure operators.

Defensive priority

medium

Recommended defensive actions

Review Siemens ProductCERT advisory SSA-355557 for definitive affected product list and patch availability
Verify SINEC OS version on RUGGEDCOM RST2428P and SCALANCE XC/XR family devices
Apply kernel updates provided by Siemens through established maintenance channels
Monitor CISA ICS advisories for additional guidance on ICSA-25-226-07
Implement defense-in-depth strategies per CISA ICS recommended practices for industrial control systems

Evidence notes

Vulnerability description derived from CISA CSAF source ICSA-25-226-07. Siemens vendor identification confirmed through csaf_product_tree_vendor field. Timeline dates sourced from CVE publishedAt and modifiedAt fields per source corpus. Threat categorization as 'Misinformed' documented in source threats array with product_ids CSAFPID-0006, CSAFPID-0002, CSAFPID-0003. Advisory revision history confirms February 25, 2026 republication based on Siemens SSA-355557. No KEV listing present; enrichment.isKev is false with null kevDateAdded.

Official resources

2025-08-12