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CVE-2024-56548 Siemens CVE debrief

CVE-2024-56548 is a medium-severity vulnerability (CVSS 5.5) in the Linux kernel's hfsplus filesystem driver, published on 2025-08-12 and last modified on 2026-02-25. The vulnerability stems from a block size mismatch condition: when a loop device's block size is modified via the LOOP_SET_BLOCK_SIZE ioctl, the hfsplus driver may allocate memory based on the new block size but subsequently perform I/O operations using a different io_size, leading to potential out-of-bounds writes. This local attack vector requires low privileges and no user interaction, with availability impact rated as high. Siemens has identified affected products in its industrial networking portfolio, including the RUGGEDCOM RST2428P and SCALANCE XC/XR/XCM/XRM/XCH/XRH families. Vendor fixes are available, with updates to V3.2 or later versions recommended for affected RUGGEDCOM and SCALANCE XCM-/XRM-/XCH-/XRH-300 products; SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family configurations should consult vendor documentation for specific guidance.

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, SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500, or SCALANCE XCM-/XRM-/XCH-/XRH-300 family products in industrial environments; security teams managing Linux-based industrial control systems utilizing hfsplus filesystems on loop devices; OT security practitioners responsible for patch management in critical infrastructure sectors.

Technical summary

The hfsplus filesystem driver in the Linux kernel contains a vulnerability where block size changes on loop devices (via LOOP_SET_BLOCK_SIZE ioctl) can cause memory allocation and I/O size mismatches. When hfsplus_read_wrapper calls hfsplus_submit_bio, the function may read a different io_size than what was used for allocation, resulting in potential out-of-bounds writes. This is a local vulnerability requiring low privileges with no user interaction, affecting availability. Siemens industrial networking products incorporating vulnerable kernel versions are affected, with vendor fixes available as of the 2026-02-25 advisory update.

Defensive priority

medium

Recommended defensive actions

  • Apply vendor-provided updates to V3.2 or later for RUGGEDCOM RST2428P and SCALANCE XCM-/XRM-/XCH-/XRH-300 family products per Siemens guidance
  • Review Siemens ProductCERT SSA-355557 for specific configuration guidance on SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family products
  • Implement defense-in-depth strategies for industrial control systems as recommended by CISA
  • Monitor for anomalous local filesystem activity on systems utilizing hfsplus-formatted loop devices
  • Restrict local access to systems running affected Siemens networking products to authorized personnel only

Evidence notes

CVE description and CVSS vector from official CVE record; affected products and remediation details from CISA CSAF advisory ICSA-25-226-07, which republishes Siemens ProductCERT SSA-355557 advisory dated 2026-02-25.

Official resources

2025-08-12