Vulnerability · Published Mar 26, 2021 · Assigned by GitHub_M

CVE-2021-21372Nimble arbitrary code execution for specially crafted package metadata

High 8.3

In plain English

A high-severity improper input validation in security from nim-lang. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 3.6% (higher than 90% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.3High

Exploit odds (30 days)3.6%top 10.4% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

Nimble is a package manager for the Nim programming language. In Nim release version before versions 1.2.10 and 1.4.4, Nimble doCmd is used in different places and can be leveraged to execute arbitrary commands. An attacker can craft a malicious entry in the packages.json package list to trigger code execution.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	nim	1.4.6+really1.4.2-1	DEBIAN-CVE-2021-21372
Debian:14	nim	1.4.6+really1.4.2-1	DEBIAN-CVE-2021-21372
Ubuntu:24.04:LTS	nim	no fix listed	UBUNTU-CVE-2021-21372
Ubuntu:25.10	nim	no fix listed	UBUNTU-CVE-2021-21372
Ubuntu:26.04:LTS	nim	no fix listed	UBUNTU-CVE-2021-21372
Ubuntu:26.10	nim	no fix listed	UBUNTU-CVE-2021-21372

Affected products (as reported)

Vendor	Product	Versions
nim-lang	security	< 1.2.10>= 1.4.0, < 1.4.4

Weakness: CWE-20, CWE-74 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H

References

https://consensys.net/diligence/vulnerabilities/nim-insecure-ssl-tls-defaults-remote-code-execution/ x_refsource_MISC
https://github.com/nim-lang/security/security/advisories/GHSA-rg9f-w24h-962p x_refsource_CONFIRM
https://github.com/nim-lang/nimble/blob/master/changelog.markdown#0130 x_refsource_MISC
https://github.com/nim-lang/nimble/commit/7bd63d504a4157b8ed61a51af47fb086ee818c37 x_refsource_MISC