CVE-2025-21744

Kernel crash via stale interface dereference

Published Feb 27, 2025 · Updated May 23, 2026

A NULL pointer dereference in the Linux brcmfmac driver allows local users to crash the kernel during device or module teardown. brcmf_get_ifp() returns NULL after brcmf_del_if() invalidates the interface mapping, but brcmf_txfinalize() dereferences ifp->ndev while updating tx_errors. The fault requires a flowring that still contains an skb and local low-privilege access capable of initiating teardown; no data disclosure or modification is reported.

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

A NULL pointer dereference in the Linux brcmfmac driver allows local users to crash the kernel during device or module teardown. brcmf_get_ifp() returns NULL after brcmf_del_if() invalidates the interface mapping, but brcmf_txfinalize() dereferences ifp->ndev while updating tx_errors. The fault requires a flowring that still contains an skb and local low-privilege access capable of initiating teardown; no data disclosure or modification is reported.

The record

CVE
CVE-2025-21744
Published
Feb 27, 2025
Updated
May 23, 2026
Vendor
Siemens
Product
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 27, 2025CVE publishedPublication date reported by the CVE source.
  2. May 23, 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=0 <*

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Siemens · SIMATIC S7-1500 TM MFP - GNU/Linux subsystemversion=0 <*
The Linux Kernel Organization · Linuxversion=4.7.10 <4.8; version=4.8.4 <4.9; version=4.9; version=6faa698c35a43b9e74ea24e90fe37471d08d00d0; version=7f00ee2bbc630900ba16fc2690473f3e2db0e264 <2326e19190e176fd72bb542b837a9d2b7fcb8693; version=7f00ee2bbc630900ba16fc2690473f3e2db0e264 <3877fc67bd3d5566cc12763bce39710ceb74a97d; version=7f00ee2bbc630900ba16fc2690473f3e2db0e264 <4e51d6d093e763348916e69d06d87e0a5593661b; version=7f00ee2bbc630900ba16fc2690473f3e2db0e264 <59ff4fa653ff6db07c61152516ffba79c2a74bda; version=7f00ee2bbc630900ba16fc2690473f3e2db0e264 <61541d9b5a23df33934fcc620a3a81f246b1b240; version=7f00ee2bbc630900ba16fc2690473f3e2db0e264 <68abd0c4ebf24cd499841a488b97a6873d5efabb; version=7f00ee2bbc630900ba16fc2690473f3e2db0e264 <a2beefc4fa49ebc22e664dc6b39dbd054f8488f9; version=7f00ee2bbc630900ba16fc2690473f3e2db0e264 <fbbfef2a5b858eab55741a58b2ac9a0cc8d53c58; version=9119232cc92a269d7860b4aa51f07d3923a3cc10

Published CVSS scores

5.5Canonical UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5Siemens ProductCERTCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5NIST NVDCVSS: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
T1499Endpoint Denial of Service

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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