Vulnerability · Published Aug 25, 2021 · Assigned by mitre
CVE-2021-40084
Critical 9.8
In plain English
A critical-severity security flaw in the opensysusers package (Debian). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.9% (higher than 87% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)9.8Critical
Exploit odds (30 days)2.9%top 12.8% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | opensysusers | 0.6-3 | DEBIAN-CVE-2021-40084 |
| Debian:13 | opensysusers | 0.6-3 | DEBIAN-CVE-2021-40084 |
| Debian:14 | opensysusers | 0.6-3 | DEBIAN-CVE-2021-40084 |
| Ubuntu:22.04:LTS | opensysusers | no fix listed | UBUNTU-CVE-2021-40084 |
| Ubuntu:24.04:LTS | opensysusers | no fix listed | UBUNTU-CVE-2021-40084 |
| Ubuntu:25.10 | opensysusers | no fix listed | UBUNTU-CVE-2021-40084 |
| Ubuntu:26.04:LTS | opensysusers | no fix listed | UBUNTU-CVE-2021-40084 |
Affected products (as reported)
References
- https://bugs.debian.org/992058 x_refsource_MISC
- https://github.com/artix-linux/opensysusers/releases x_refsource_MISC