CVE-2025-21682Public exploit

Kernel crash via stale RSS ring map

Published Jan 31, 2025 · Updated Sep 8, 2026

NULL pointer dereference in the bnxt driver allows local users to crash Linux and affected Siemens SIMATIC controller kernels. __bnxt_reserve_rings() skips RSS-map refresh when pending HW-GRO re-enablement and a halved ring count cancel, leaving stale indices that access a freed ring. Triggering the crash requires CAP_NET_ADMIN over a Broadcom bnxt network device and attaching and detaching XDP before reducing channels.

CVSS severity5.5
Medium
EPSS probability0.23%
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 bnxt driver allows local users to crash Linux and affected Siemens SIMATIC controller kernels. __bnxt_reserve_rings() skips RSS-map refresh when pending HW-GRO re-enablement and a halved ring count cancel, leaving stale indices that access a freed ring. Triggering the crash requires CAP_NET_ADMIN over a Broadcom bnxt network device and attaching and detaching XDP before reducing channels.

The record

CVE
CVE-2025-21682
Published
Jan 31, 2025
Updated
Sep 8, 2026
Vendor
Siemens
Product
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 31, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=V3.1.5 <*
  2. 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=V3.1.5 <*; version=V3.1.6 <*
The Linux Kernel Organization · Linuxversion=1054aee82321483dceabbb9b9e5d6512e8fe684b <076a694a42ae3f0466bc6e4126050eeb7b7d299a; version=1054aee82321483dceabbb9b9e5d6512e8fe684b <08831a894d18abfaabb5bbde7c2069a7fb41dd93; version=1054aee82321483dceabbb9b9e5d6512e8fe684b <90336fc3d6f5e716ac39a9ddbbde453e23a5aa65; version=1054aee82321483dceabbb9b9e5d6512e8fe684b <f0aa6a37a3dbb40b272df5fc6db93c114688adcd; version=4.16
Siemens · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPversion=V3.1.5 <*; version=V3.1.6 <*
Siemens · SIMATIC S7-1500 CPU 1518-4 PN/DP MFPversion=V3.1.5 <*; version=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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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