What is CVE-2021-40084?

CVE-2021-40084 is a critical-severity vulnerability in Artixlinux Opensysusers, classified under Code Injection. CVSS score: 9.8/10. Published 2021-08-25.

How severe is CVE-2021-40084?

Critical severity. CVSS v3 base score is 9.8 out of 10.

RCE in Artixlinux Opensysusers

CVE-2021-40084

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.

Vulnerability class: RCE (Remote Code Execution)

Published 2021-08-25 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.027 (85.5th percentile), scored 2026-10-08.

Low probability of exploitation in the next 30 days, but still tracked. 86th percentile — 85.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.027 · newest: 0.027 · change: 0.000

Affected products

Artixlinux Opensysusers

Weakness classification (CWE)

CWE-94 — Code Injection

References

bugs.debian.org/992058 (Exploit, Mailing List, Third Party Advisory)
github.com/artix-linux/opensysusers/releases (Third Party Advisory, Release Notes)

Frequently asked questions

What is CVE-2021-40084?: CVE-2021-40084 is a critical-severity vulnerability in Artixlinux Opensysusers, classified under Code Injection. CVSS score: 9.8/10. Published 2021-08-25.
How severe is CVE-2021-40084?: Critical severity. CVSS v3 base score is 9.8 out of 10.