CVE-2021-42257

Name: CVE-2021-42257
Creator: NVD / NIST
Published: 2021-10-11T20:15:07.373+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.1/10EPSS 0.38%

Last modified Jun 17, 2026

CVE-2021-42257 is a high-severity vulnerability rated 7.1/10 on the CVSS scale. check_smart before 6.9.1 allows unintended drive access by an unprivileged user because it only checks for a substring match of a device path (the /dev/bus substring and a number), aka an unanchored regular expression.. EPSS estimates a 0.38% chance of exploitation in the next 30 days.

Description

check_smart before 6.9.1 allows unintended drive access by an unprivileged user because it only checks for a substring match of a device path (the /dev/bus substring and a number), aka an unanchored regular expression.

Metrics

CVSS 3.1

7.1/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

EPSS Probability

0.38%

29.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-20

Affected Software

Vendor	Product	Versions
Check Smart Project	Check Smart	< 6.9.1

References

http://www.openwall.com/lists/oss-security/2021/10/14/2Exploit, Third Party Advisory
https://bugzilla.suse.com/show_bug.cgi?id=1183057Exploit, Issue Tracking, Patch, Third Party Advisory
https://nvd.nist.gov/vuln/detail/CVE-2021-42257
https://www.claudiokuenzler.com/blog/1068/check_smart-6.9.1-security-fix-release-pseudo-device-pathThird Party Advisory
https://www.claudiokuenzler.com/monitoring-plugins/check_smart.phpThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/14/2Exploit, Third Party Advisory
https://bugzilla.suse.com/show_bug.cgi?id=1183057Exploit, Issue Tracking, Patch, Third Party Advisory
https://nvd.nist.gov/vuln/detail/CVE-2021-42257
https://www.claudiokuenzler.com/blog/1068/check_smart-6.9.1-security-fix-release-pseudo-device-pathThird Party Advisory
https://www.claudiokuenzler.com/monitoring-plugins/check_smart.phpThird Party Advisory

Timeline

Published: Oct 11, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-42257?

How severe is CVE-2021-42257?

CVE-2021-42257 has a CVSS score of 7.1/10 (HIGH severity). The EPSS model estimates a 0.38% probability of exploitation in the next 30 days.

How do I fix CVE-2021-42257?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-42257?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST