PatchSiren

PatchSiren cyber security CVE debrief

CVE-2024-56593 Siemens CVE debrief

CVE-2024-56593 is a NULL pointer dereference vulnerability in the Linux kernel's brcmfmac Wi-Fi driver, specifically within the `brcmf_sdiod_sglist_rw()` function. The flaw manifests when a high `sd_sgentry_align` value (e.g., 512) is configured and numerous queued SKBs (socket buffers) are transmitted from the packet queue, potentially causing a kernel oops (crash). 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 and related industrial networking products. CISA republished this advisory as ICSA-25-226-07. Notably, the CISA CSAF source marks the impact assessment for affected Siemens products as 'Misinformed,' indicating potential discrepancies in initial severity or applicability assessments. The vulnerability affects Siemens industrial networking equipment including RUGGEDCOM RST2428P and SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family devices running SINEC OS. No CVSS score is currently available in the source data.

Vendor
Siemens
Product
RUGGEDCOM RST2428P (6GK6242-6PA00)
CVSS
Unknown
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 with Wi-Fi capabilities, particularly RUGGEDCOM RST2428P and SCALANCE XC/XR series devices. OT security teams managing SINEC OS deployments and Linux-based industrial gateways using Broadcom FullMAC Wi-Fi chipsets should prioritize patch verification.

Technical summary

The vulnerability exists in the brcmfmac driver's SDIO scatter-gather list read/write function. When `sd_sgentry_align` is set to high values (512 bytes) and the packet queue contains many queued SKBs, the driver may dereference a NULL pointer during scatter-gather operations, resulting in a kernel oops. This is a memory safety defect in kernel-space Wi-Fi driver code handling DMA-aligned buffer operations. The flaw is triggered under specific memory pressure and alignment conditions during high-volume packet transmission scenarios.

Defensive priority

medium

Recommended defensive actions

  • Review Siemens ProductCERT advisory SSA-355557 for detailed product-specific patch availability and version information
  • Verify SINEC OS and brcmfmac driver versions on affected Siemens RUGGEDCOM and SCALANCE devices
  • Apply kernel updates or vendor-provided patches that address the NULL pointer dereference in brcmf_sdiod_sglist_rw()
  • Monitor CISA ICS advisories for updates to ICSA-25-226-07 regarding corrected impact assessments
  • Implement network segmentation for industrial Wi-Fi deployments to limit exposure of vulnerable brcmfmac-dependent systems
  • Consult Siemens support for guidance on `sd_sgentry_align` configuration mitigations if immediate patching is not feasible

Evidence notes

Vulnerability description derived from CISA CSAF advisory ICSA-25-226-07 and Siemens ProductCERT SSA-355557. Impact assessment marked 'Misinformed' per source threats data. Affected products identified from CSAF product tree.

Official resources

2025-08-12