CVE-2021-47290

Kernel crash via XCOPY completion NULL dereference

Published May 21, 2024 · Updated Aug 5, 2026

NULL pointer dereference in Linux kernel 5.13 through 5.13.5 allows local users to crash the system through LIO EXTENDED COPY I/O. LIO's global xcopy_pt_tpg is initialized without se_tpg_wwn, but target_complete_cmd dereferences that pointer while completing XCOPY-issued reads or writes. Reachability requires local low-privileged access to initiate an EXTENDED COPY operation against an LIO SCSI target, and successful triggering interrupts the host through a kernel crash.

CVSS severity5.5
Medium
EPSS probability0.46%
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 5.13 through 5.13.5 allows local users to crash the system through LIO EXTENDED COPY I/O. LIO's global xcopy_pt_tpg is initialized without se_tpg_wwn, but target_complete_cmd dereferences that pointer while completing XCOPY-issued reads or writes. Reachability requires local low-privileged access to initiate an EXTENDED COPY operation against an LIO SCSI target, and successful triggering interrupts the host through a kernel crash.

The record

CVE
CVE-2021-47290
Published
May 21, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=39ae3edda325e9cf9e978c9788affe88231f3b34 <a47fa41381a09e5997afd762664db4f5f6657e03
  2. Affected versionversion=39ae3edda325e9cf9e978c9788affe88231f3b34 <e7732c5a19a15a62b0b23fd683a639b0483e1f40
  3. Affected versionversion=5.13

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=39ae3edda325e9cf9e978c9788affe88231f3b34 <a47fa41381a09e5997afd762664db4f5f6657e03; version=39ae3edda325e9cf9e978c9788affe88231f3b34 <e7732c5a19a15a62b0b23fd683a639b0483e1f40; version=5.13

Published CVSS scores

5.5NISTCVSS: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
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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