CVE-2021-47002

Kernel crash via unchecked scratch-page allocation failure

Published Feb 28, 2024 · Updated May 23, 2026

NULL pointer dereference in Linux SUNRPC allows local users to crash affected kernels after a page allocation failure. svc_rqst_alloc can leave rq_scratch_page null when alloc_pages_node fails, and svc_rqst_free passes that null pointer to put_page without checking it. Reaching the fault requires the SUNRPC request-allocation cleanup path and a failed scratch-page allocation; published sources document no confidentiality or integrity impact.

CVSS severity5.5
Medium
EPSS probability0.24%
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 Linux SUNRPC allows local users to crash affected kernels after a page allocation failure. svc_rqst_alloc can leave rq_scratch_page null when alloc_pages_node fails, and svc_rqst_free passes that null pointer to put_page without checking it. Reaching the fault requires the SUNRPC request-allocation cleanup path and a failed scratch-page allocation; published sources document no confidentiality or integrity impact.

The record

CVE
CVE-2021-47002
Published
Feb 28, 2024
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 28, 2024CVE 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=5.10.220 <5.10.221; version=5.11; version=5191955d6fc65e6d4efe8f4f10a6028298f57281 <1e10f58f1c9a6b667b045513c7a4e6111c24fe7c; version=5191955d6fc65e6d4efe8f4f10a6028298f57281 <b9f83ffaa0c096b4c832a43964fe6bff3acffe10; version=5191955d6fc65e6d4efe8f4f10a6028298f57281 <c664aaec9aee544538a78ba4893a44bc73a6d742; version=79e4e0d489c8e72b9efa388e504a036eec1550c6 <3de81c1e84bf84803308da3272a829a7655c5336

Published CVSS scores

5.5NIST National Vulnerability DatabaseCVSS: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 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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