CVE-2021-47067

System hang via unenforced regulator voltage spread

Published Feb 29, 2024 · Updated May 11, 2026

Improper locking in the Linux kernel allows local users to hang Tegra30 systems through out-of-range coupled regulator voltages. The Tegra30 regulator driver fails to enforce the coupled maximum-spread constraint when the CPU regulator has no consumers, leaving voltage adjustment unable to converge. Reachability requires Tegra30 hardware and system-wide DVFS enabled in the device tree; the resulting voltage-coupler lockup interrupts the system.

CVSS severity5.5
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper locking in the Linux kernel allows local users to hang Tegra30 systems through out-of-range coupled regulator voltages. The Tegra30 regulator driver fails to enforce the coupled maximum-spread constraint when the CPU regulator has no consumers, leaving voltage adjustment unable to converge. Reachability requires Tegra30 hardware and system-wide DVFS enabled in the device tree; the resulting voltage-coupler lockup interrupts the system.

The record

CVE
CVE-2021-47067
Published
Feb 29, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-667, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 29, 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=5.5
  2. Affected versionversion=783807436f363e5b1ad4d43ba7debbedfcadbb99 <a1ad124c836816fac8bd5e461d36eaf33cee4e24
  3. Affected versionversion=783807436f363e5b1ad4d43ba7debbedfcadbb99 <dc4452867200fa94589b382740952b58aa1c3e6c
  4. Affected versionversion=783807436f363e5b1ad4d43ba7debbedfcadbb99 <ef85bb582c41524e9e68dfdbde48e519dac4ab3d
  5. Affected versionversion=783807436f363e5b1ad4d43ba7debbedfcadbb99 <ff39adf5d31c72025bba799aec69c5c86d81d549

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.5; version=783807436f363e5b1ad4d43ba7debbedfcadbb99 <a1ad124c836816fac8bd5e461d36eaf33cee4e24; version=783807436f363e5b1ad4d43ba7debbedfcadbb99 <dc4452867200fa94589b382740952b58aa1c3e6c; version=783807436f363e5b1ad4d43ba7debbedfcadbb99 <ef85bb582c41524e9e68dfdbde48e519dac4ab3d; version=783807436f363e5b1ad4d43ba7debbedfcadbb99 <ff39adf5d31c72025bba799aec69c5c86d81d549

Published CVSS scores

5.5NIST NVDCVSS: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-667Improper Locking
T1499Endpoint Denial of Service

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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