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PatchSiren cyber security CVE debrief

CVE-2025-38466 Siemens CVE debrief

CVE-2025-38466 is a Linux kernel issue in uprobes handling that led to a reversion to requiring CAP_SYS_ADMIN. The source text says the kernel can verify that an instruction exists at a requested offset, but it cannot always determine whether that offset corresponds to the intended execution stream; the advisory also notes risk on architectures that mix data in the text segment. Siemens’ CSAF advisory maps this issue to specific SIMATIC S7-1500 CPU 1518/1518F MFP products and, in the supplied source, lists mitigation guidance rather than a fixed version. The practical defensive takeaway is to tightly control access to the embedded GNU/Linux subsystem and limit it to trusted personnel and trusted software.

Vendor
Siemens
Product
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2025-06-10
Original CVE updated
2026-05-14
Advisory published
2025-06-10
Advisory updated
2026-05-14

Who should care

OT/ICS operators, Siemens SIMATIC S7-1500 MFP administrators, and teams responsible for embedded Linux access control, especially where the additional GNU/Linux subsystem is reachable by service staff or third-party software.

Technical summary

The underlying Linux kernel change restores a CAP_SYS_ADMIN gate for uprobes. According to the source description, uprobes can be positioned in the middle of an instruction, and because instruction length is variable the kernel cannot fully determine whether the probed offset matches the intended execution stream. Siemens’ advisory maps the issue to SIMATIC S7-1500 CPU 1518/1518F MFP variants and recommends limiting interactive shell access to trusted personnel and only building/running applications from trusted sources. The supplied CVSS vector is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H, indicating local access prerequisites and a high availability impact.

Defensive priority

Medium

Recommended defensive actions

  • Confirm whether any listed SIMATIC S7-1500 CPU 1518/1518F MFP variants are deployed in your environment.
  • Restrict interactive shell access to the additional GNU/Linux subsystem to trusted personnel only, as recommended by Siemens.
  • Only install, build, and run trusted applications on the embedded Linux environment.
  • Review local account, maintenance, and service workflows to remove unnecessary access to shell or debug functions.
  • Monitor Siemens ProductCERT and CISA advisory updates for a future fix or revised guidance.

Evidence notes

The supplied source item is CISA’s CSAF republication for ICSA-25-162-05, which points to Siemens SSA-082556 and maps CVE-2025-38466 to five SIMATIC S7-1500 CPU product variants. The remediations section states that no fix is currently available and provides mitigation guidance focused on limiting shell access and trusted software use. The advisory was first published on 2025-06-10 and last updated on 2026-05-14 in the supplied timeline.

Official resources

Public advisory published 2025-06-10; latest supplied source update/republication 2026-05-14. The supplied corpus does not indicate a Known Exploited Vulnerabilities listing, and the advisory text provides mitigations only with no fix yet.