CVE-2021-47503

System crash via premature SCSI host removal

Published May 24, 2024 · Updated May 11, 2026

NULL pointer dereference in Linux kernel 5.10 through 5.15.7 allows local users to crash the system during pm80xx device probing. pm8001_alloc invokes scsi_remove_host on its probe-error path before scsi_add_host has registered the SCSI host, so device_del dereferences an uninitialized device pointer. Reachability requires a pm80xx controller and entry into the PCI probe failure path; the demonstrated consequence is a kernel crash, not data access or modification.

CVSS severity6.2
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 Linux kernel 5.10 through 5.15.7 allows local users to crash the system during pm80xx device probing. pm8001_alloc invokes scsi_remove_host on its probe-error path before scsi_add_host has registered the SCSI host, so device_del dereferences an uninitialized device pointer. Reachability requires a pm80xx controller and entry into the PCI probe failure path; the demonstrated consequence is a kernel crash, not data access or modification.

The record

CVE
CVE-2021-47503
Published
May 24, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 24, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=05c6c029a44d9f43715577e33e95eba87f44d285 <1e434d2687e8bc0b3cdc9dd093c0e9047c0b4add
  2. Affected versionversion=05c6c029a44d9f43715577e33e95eba87f44d285 <653926205741add87a6cf452e21950eebc6ac10b
  3. Affected versionversion=05c6c029a44d9f43715577e33e95eba87f44d285 <f8dccc1bdea7e21b5ec06c957aef8831c772661c
  4. Affected versionversion=5.10

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=05c6c029a44d9f43715577e33e95eba87f44d285 <1e434d2687e8bc0b3cdc9dd093c0e9047c0b4add; version=05c6c029a44d9f43715577e33e95eba87f44d285 <653926205741add87a6cf452e21950eebc6ac10b; version=05c6c029a44d9f43715577e33e95eba87f44d285 <f8dccc1bdea7e21b5ec06c957aef8831c772661c; version=5.10
The Linux Kernel Organization · Linux Kernelversion=05c6c029a44d <1e434d2687e8; version=05c6c029a44d <f8dccc1bdea7; version=5.10; version=f8dccc1bdea7 <653926205741

Published CVSS scores

6.2CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/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
Privilegesunauthenticated
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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