CVE-2021-42257Public exploit

Drive shutdown via unanchored device-path validation

Published Oct 11, 2021 · Updated Aug 4, 2024

Improper input validation in check_smart 6.1 through 6.9 allows local users to alter drive settings through the -d option. The option's unanchored /dev/bus/\d substring check accepts attacker-controlled paths and passes the resulting string verbatim as arguments to privileged smartctl. Exploitation requires permission to run check_smart through sudo; injected smartctl options can disable SMART monitoring or read caching, or shut down a drive.

CVSS severity7.1
High
EPSS probability0.39%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in check_smart 6.1 through 6.9 allows local users to alter drive settings through the -d option. The option's unanchored /dev/bus/\d substring check accepts attacker-controlled paths and passes the resulting string verbatim as arguments to privileged smartctl. Exploitation requires permission to run check_smart through sudo; injected smartctl options can disable SMART monitoring or read caching, or shut down a drive.

The record

CVE
CVE-2021-42257
Published
Oct 11, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, T1548.003
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

3.6NIST NVDAV:L/AC:L/Au:N/C:N/I:P/A:P
7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/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 exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
T1548.003Sudo and Sudo Caching

Public exploit references

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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