CVE-2025-21814

Local kernel crash via missing PTP callback

Published Feb 27, 2025 · Updated Sep 8, 2026

NULL pointer dereference in the Linux PTP subsystem allows local users to crash affected systems through PTP ioctl or sysfs handlers. The handlers unconditionally invoke info->enable even when a registered driver, including ptp_s390, ptp_vclock, or ptp_mock, supplies no callback. A local low-privileged user needs access to an affected PTP interface; invoking the missing callback causes a kernel NULL dereference and service interruption.

CVSS severity5.5
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the Linux PTP subsystem allows local users to crash affected systems through PTP ioctl or sysfs handlers. The handlers unconditionally invoke info->enable even when a registered driver, including ptp_s390, ptp_vclock, or ptp_mock, supplies no callback. A local low-privileged user needs access to an affected PTP interface; invoking the missing callback causes a kernel NULL dereference and service interruption.

The record

CVE
CVE-2025-21814
Published
Feb 27, 2025
Updated
Sep 8, 2026
Vendor
Siemens
Product
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
Classifications
CWE-476
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 27, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=V3.1.6 <*

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Siemens · SIPLUS S7-1500 CPU 1518-4 PN/DP MFPversion=V3.1.6 <*
Siemens · SIMATIC S7-1500 TM MFP - GNU/Linux subsystemversion=0 <*
The Linux Kernel Organization · Linuxversion=3.0; version=d94ba80ebbea17f036cecb104398fbcd788aa742 <1334c64a5d1de6666e0c9f984db6745083df1eb4; version=d94ba80ebbea17f036cecb104398fbcd788aa742 <5d1041c76de656f9f8d5a192218039a9acf9bd00; version=d94ba80ebbea17f036cecb104398fbcd788aa742 <755caf4ee1c615ee5717862e427124370f46b1f3; version=d94ba80ebbea17f036cecb104398fbcd788aa742 <81846070cba17125a866e8023c01d3465b153339; version=d94ba80ebbea17f036cecb104398fbcd788aa742 <8441aea46445252df5d2eed6deb6d5246fc24002; version=d94ba80ebbea17f036cecb104398fbcd788aa742 <9df3a9284f39bfd51a9f72a6a165c79e2aa5066b; version=d94ba80ebbea17f036cecb104398fbcd788aa742 <fd53aa40e65f518453115b6f56183b0c201db26b; version=d94ba80ebbea17f036cecb104398fbcd788aa742 <fdc1e72487781dd7705bcbe30878bee7d5d1f3e8
Siemens · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPversion=V3.1.6 <*
Siemens · SIMATIC S7-1500 CPU 1518-4 PN/DP MFPversion=V3.1.6 <*

Published CVSS scores

5.5Siemens ProductCERTCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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