PatchSiren cyber security CVE debrief

CVE-2023-52486 Siemens CVE debrief

CVE-2023-52486 is a vulnerability in the Linux kernel's Direct Rendering Manager (DRM) subsystem. The issue involves improper reference counting of framebuffers (fb) during deadlock handling scenarios, where the same framebuffer could be unreferenced multiple times by mistake. This use-after-free style error could lead to memory corruption or system instability. The vulnerability was resolved in the Linux kernel with a fix that prevents duplicate unreferencing of framebuffers during deadlock recovery paths. Siemens has identified this CVE as affecting certain industrial networking products including the RUGGEDCOM RST2428P and SCALANCE X-family switches that incorporate the vulnerable Linux kernel components. CISA published advisory ICSA-25-226-15 on August 12, 2025, with subsequent updates through February 25, 2026, to refine affected product listings and incorporate corrections from Siemens ProductCERT advisory SSA-613116. The threat assessment categorizes impact as 'Misinformed' per the CSAF data. No known exploitation in ransomware campaigns has been documented. Organizations operating affected Siemens industrial networking equipment should consult vendor guidance for patch availability and apply kernel updates as provided through SINEC OS or device firmware releases.

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 Ethernet switches and routers, particularly in critical infrastructure environments. System administrators managing SCALANCE X-family or RUGGEDCOM devices with SINEC OS. Security teams responsible for OT/ICS network security and vulnerability management programs. Asset owners in manufacturing, energy, transportation, and other sectors deploying affected networking equipment.

Technical summary

The vulnerability exists in the Linux kernel's DRM (Direct Rendering Manager) subsystem, specifically in framebuffer reference counting logic during deadlock handling. When a deadlock condition occurs, the error recovery path could incorrectly unreference the same framebuffer multiple times, leading to a use-after-free condition. This is a classic reference counting bug where the cleanup path lacks proper state tracking to prevent duplicate decrements. The fix ensures that framebuffer unreferencing occurs exactly once per logical operation, even when retry or recovery paths are exercised. Affected Siemens products incorporate the vulnerable kernel code in their embedded systems, particularly those running SINEC OS on SCALANCE XC/XR/XCM/XRM/XCH/XRH families and RUGGEDCOM RST2428P platforms.

Defensive priority

medium

Recommended defensive actions

Review Siemens ProductCERT advisory SSA-613116 for detailed affected product versions and patch availability
Verify SINEC OS or firmware version on affected SCALANCE and RUGGEDCOM devices
Apply vendor-provided kernel updates or firmware patches when available
Monitor CISA ICS advisories for additional guidance on industrial control system security practices
Implement network segmentation for industrial control systems per CISA recommended practices

Evidence notes

Vulnerability description sourced from CISA CSAF advisory ICSA-25-226-15 and Linux kernel commit message. Affected product identification derived from Siemens ProductCERT SSA-613116 CSAF product tree. Timeline based on CISA advisory publication (2025-08-12) and subsequent revisions through 2026-02-25. No CVSS score available in source corpus.

Official resources

2025-08-12