PatchSiren cyber security CVE debrief

CVE-2024-50095 Siemens CVE debrief

A locking contention vulnerability in the Linux kernel's RDMA MAD (Management Datagram) agent timeout handler can cause soft lockups when processing a high volume of timed-out Work Requests (WRs). The original implementation acquired and released the mad_agent_priv lock for each timed-out WR, creating severe contention under load. This manifests during RDMA-CM connection establishment between peer nodes. The fix simplifies the timeout handler by creating a local list of timed-out WRs with a single lock acquisition/release cycle, significantly reducing locking overhead.

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 industrial network infrastructure including RUGGEDCOM RST2428P switches and SCALANCE XC/XR/XCM/XRM/XCH/XRH families, particularly those utilizing RDMA-CM for high-performance computing or storage networking in industrial environments.

Technical summary

The vulnerability exists in the RDMA MAD agent timeout handler within the Linux kernel. When processing timed-out Work Requests (WRs), the original implementation performed individual lock acquisitions and releases for each WR, causing heavy locking contention. Under high-load scenarios involving RDMA-CM connection establishment between peer nodes, this contention leads to soft lockups. The resolution creates a local list of timed-out WRs and processes them with a single lock acquisition/release cycle, eliminating the per-WR locking overhead.

Defensive priority

medium

Recommended defensive actions

Apply vendor-provided firmware updates to affected Siemens industrial network devices
For RUGGEDCOM RST2428P and SCALANCE XCM-/XRM-/XCH-/XRH-300 family, update to V3.2 or later
For SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family, consult vendor documentation for specific update guidance
Monitor RDMA-CM connection establishment for signs of soft lockup or system unresponsiveness
Implement network segmentation for RDMA-enabled industrial control systems
Review and apply CISA ICS recommended practices for defense-in-depth strategies

Evidence notes

The vulnerability was resolved in the Linux kernel RDMA/mad subsystem. The issue was identified through soft lockup traces observed during RDMA-CM path usage for peer node connection establishment. The root cause was excessive lock contention in the timeout handler when processing multiple timed-out WRs.

Sources and references

Verified primary and authoritative sources

CVE-2024-50095 CVE Program record
Publisher, destination, and source semantics verified

URL: https://www.cve.org/CVERecord?id=CVE-2024-50095

CVE Program - Official CVE Program record with source-provided CVE metadata.
CVE-2024-50095 NVD vulnerability detail
Publisher, destination, and source semantics verified

URL: https://nvd.nist.gov/vuln/detail/CVE-2024-50095

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/2025/icsa-25-226-07.json

cisa_csaf
Source reference
Unverified legacy reference

URL: https://cert-portal.siemens.com/productcert/csaf/ssa-355557.json

Reference
Source reference
Unverified legacy reference

URL: https://cert-portal.siemens.com/productcert/html/ssa-355557.html

Reference
Source reference
Unverified legacy reference

URL: https://www.cisa.gov/news-events/ics-advisories/icsa-25-226-07

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.