PatchSiren cyber security CVE debrief

CVE-2024-35973 Siemens CVE debrief

CVE-2024-35973 is a medium-severity vulnerability (CVSS 5.5) affecting the GENEVE tunneling implementation in the Linux kernel, specifically in the `geneve_xmit_skb` function. The issue involves improper header validation that could lead to a denial-of-service condition. Siemens has identified this vulnerability as affecting certain industrial networking products running SINEC OS, including the RUGGEDCOM RST2428P and SCALANCE X-family switches. The vulnerability requires local access with low privileges to exploit, and successful exploitation results in high availability impact with no confidentiality or integrity impact. Siemens has released updates to address this issue, recommending affected users upgrade to SINEC OS V3.1 or later.

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 including SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family switches, SCALANCE XCM-/XRM-/XCH-/XRH-300 family devices, and RUGGEDCOM RST2428P switches. This particularly affects OT/ICS environments utilizing GENEVE tunneling for network virtualization, cloud infrastructure providers using GENEVE in their underlying Linux kernel implementations, and security teams responsible for maintaining availability of critical industrial control system networks.

Technical summary

The vulnerability exists in the GENEVE (Generic Network Virtualization Encapsulation) implementation within the Linux kernel's `geneve_xmit_skb` function. GENEVE is a tunneling protocol used for network virtualization, commonly deployed in cloud and data center environments. The flaw involves insufficient validation of GENEVE packet headers during transmission, which can be triggered by a local attacker with low privileges. The CVSS 3.1 vector (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) indicates a local attack vector with low attack complexity, requiring low privileges and no user interaction, resulting in high availability impact. Siemens has confirmed this affects SINEC OS versions prior to 3.1 on specific industrial networking hardware. The remediation requires updating to SINEC OS V3.1 or later, which contains the corrected header validation logic.

Defensive priority

medium

Recommended defensive actions

Update affected Siemens SINEC OS devices to version 3.1 or later to remediate this vulnerability
Review network segmentation for industrial control systems to limit exposure of GENEVE tunnel endpoints
Apply defense-in-depth strategies per CISA ICS recommended practices for industrial control systems
Monitor for anomalous local access attempts on affected SCALANCE and RUGGEDCOM devices
Verify that only authorized personnel have local access to devices running SINEC OS

Evidence notes

CVE published 2025-08-12; modified 2026-02-25. Source advisory ICSA-25-226-15 from CISA CSAF. Vendor fix available requiring update to V3.1 or later. CVSS vector confirms local attack vector with low attack complexity and low privileges required.

Official resources

2025-08-12