CVE-2021-47384Network attack vector

System crash via malformed w83793 sensor value

Published May 21, 2024 · Updated May 11, 2026

NULL pointer dereference in the Linux kernel w83793 hwmon driver allows attackers to crash an affected system through a device read. When a sensor byte matches the documented bit pattern, the subclient-detection path uses the obsolete lm75 array and dereferences a NULL client pointer. Reachability requires the w83793 monitoring driver and a device that supplies the matching byte; the reported consequence is a kernel crash or instability, not data access or modification.

CVSS severity5.3
Medium
EPSS probability1.03%
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 Linux kernel w83793 hwmon driver allows attackers to crash an affected system through a device read. When a sensor byte matches the documented bit pattern, the subclient-detection path uses the obsolete lm75 array and dereferences a NULL client pointer. Reachability requires the w83793 monitoring driver and a device that supplies the matching byte; the reported consequence is a kernel crash or instability, not data access or modification.

The record

CVE
CVE-2021-47384
Published
May 21, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 21, 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=5.4
  2. Affected versionversion=cf48d17623281c2b3185030ed23f148bd47e15de <6cb01fe630eaffc5a2c3f7364436caddba286623
  3. Affected versionversion=cf48d17623281c2b3185030ed23f148bd47e15de <746011193f44f97f8784edcf8327c587946745fc
  4. Affected versionversion=cf48d17623281c2b3185030ed23f148bd47e15de <7c4fd5de39f273626a2b0f3a446d2cc85cd47616
  5. Affected versionversion=cf48d17623281c2b3185030ed23f148bd47e15de <dd4d747ef05addab887dc8ff0d6ab9860bbcd783

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.4; version=cf48d17623281c2b3185030ed23f148bd47e15de <6cb01fe630eaffc5a2c3f7364436caddba286623; version=cf48d17623281c2b3185030ed23f148bd47e15de <746011193f44f97f8784edcf8327c587946745fc; version=cf48d17623281c2b3185030ed23f148bd47e15de <7c4fd5de39f273626a2b0f3a446d2cc85cd47616; version=cf48d17623281c2b3185030ed23f148bd47e15de <dd4d747ef05addab887dc8ff0d6ab9860bbcd783

Published CVSS scores

5.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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