PatchSiren cyber security CVE debrief

CVE-2024-39499 Siemens CVE debrief

CVE-2024-39499 is a medium-severity information disclosure vulnerability in the VMware Virtual Machine Communication Interface (VMCI) driver. The flaw exists in the `event_deliver()` function where `event_msg->event_data.event` is used as an array index without proper sanitization. This user-controlled value can trigger speculative execution side-channels, potentially leaking kernel memory contents to user-space attackers. The vulnerability was published on August 12, 2025, and last modified on February 25, 2026. Siemens ProductCERT issued advisory SSA-355557 addressing this issue in their SINEC OS-based products, including RUGGEDCOM RST2428P and SCALANCE networking equipment families. CISA republished this advisory as ICSA-25-226-07. The vulnerability is not listed in CISA's Known Exploited Vulnerabilities catalog.

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 networking infrastructure including SCALANCE managed switches (XC-300/XR-300/XC-400/XR-500WG/XR-500 families), SCALANCE XCM-/XRM-/XCH-/XRH-300 families, and RUGGEDCOM RST2428P ruggedized switches. Critical infrastructure operators in energy, manufacturing, and transportation sectors deploying these devices in virtualized environments face elevated risk. Security teams responsible for OT/ICS asset management, virtualization platform administrators supporting industrial workloads, and compliance officers tracking CVE remediation for NERC CIP or IEC 62443 requirements should prioritize this advisory.

Technical summary

The vulnerability resides in the Linux kernel's VMCI (Virtual Machine Communication Interface) driver, specifically in `event_deliver()`. The function receives an `event_msg` structure from user-space, where `event_msg->event_data.event` is used directly as an array index without bounds checking or sanitization. This architectural pattern creates conditions for speculative execution attacks—similar to Spectre variants—where out-of-bounds array access during speculative execution can leak kernel memory through cache side-channels before the mis-speculation is rolled back. The attack surface requires local user-space access to the VMCI device, typical in virtualized environments where guest operating systems communicate with the hypervisor. Siemens products incorporating vulnerable Linux kernel versions with VMCI support are affected, particularly those running SINEC OS on virtualization platforms.

Defensive priority

medium

Recommended defensive actions

Apply vendor-supplied firmware updates for affected Siemens SCALANCE and RUGGEDCOM products as detailed in Siemens ProductCERT advisory SSA-355557
Implement network segmentation to limit exposure of industrial control system devices to untrusted networks
Monitor for anomalous access patterns to VMCI interfaces on virtualized industrial systems
Review and apply CISA ICS recommended practices for defense-in-depth strategies
Validate that virtualization hosts running affected Siemens products have applied relevant VMware security updates for the underlying VMCI driver

Evidence notes

Vulnerability description sourced from CISA CSAF advisory ICSA-25-226-07 and Siemens ProductCERT SSA-355557. CVSS 5.5 MEDIUM severity confirmed. Affected products identified through CSAF product tree: RUGGEDCOM RST2428P (6GK6242-6PA00), SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family, and SCALANCE XCM-/XRM-/XCH-/XRH-300 family. Advisory revision history shows multiple updates through February 2026, including corrections to affected product lists and removal of rejected CVEs.

Sources and references

Verified primary and authoritative sources

CVE-2024-39499 CVE Program record
Publisher, destination, and source semantics verified

URL: https://www.cve.org/CVERecord?id=CVE-2024-39499

CVE Program - Official CVE Program record with source-provided CVE metadata.
CVE-2024-39499 NVD vulnerability detail
Publisher, destination, and source semantics verified

URL: https://nvd.nist.gov/vuln/detail/CVE-2024-39499

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.