CVE-2021-40084

Name: CVE-2021-40084
Creator: NVD / NIST
Published: 2021-08-25T01:15:12.957+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 2.71%

Last modified Jun 17, 2026

CVE-2021-40084 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. opensysusers through 0.6 does not safely use eval on files in sysusers.d that may contain shell metacharacters. For example, it allows command execution via a crafted GECOS field whereas systemd-sysusers (a program with the same specification) does not do that.. EPSS estimates a 2.71% chance of exploitation in the next 30 days.

Description

opensysusers through 0.6 does not safely use eval on files in sysusers.d that may contain shell metacharacters. For example, it allows command execution via a crafted GECOS field whereas systemd-sysusers (a program with the same specification) does not do that.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

2.71%

84.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-94

Affected Software

Vendor	Product	Versions
Artixlinux	Opensysusers	<= 0.6

References

https://bugs.debian.org/992058Exploit, Mailing List, Third Party Advisory
https://github.com/artix-linux/opensysusers/releasesRelease Notes, Third Party Advisory
https://bugs.debian.org/992058Exploit, Mailing List, Third Party Advisory
https://github.com/artix-linux/opensysusers/releasesRelease Notes, Third Party Advisory

Timeline

Published: Aug 25, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-40084?

How severe is CVE-2021-40084?

CVE-2021-40084 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 2.71% probability of exploitation in the next 30 days.

How do I fix CVE-2021-40084?

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-2021-40084?

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

Scan your code now

Source: NVD / NIST