How severe is CVE-2021-21372?

CVE-2021-21372 has a CVSS 3.x base score of 8.3, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-21372 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21372?

CVE-2021-21372 affects Nim-lang Nim. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21372?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-21372 published?

CVE-2021-21372 was published on 2021-03-26 and last updated on 2026-06-17.

CVE-2021-21372

CVE-2021-21372 is a high-severity vulnerability in Nim-lang Nim with a CVSS 3.x base score of 8.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-78.

Key facts

Severity: High (CVSS 3.x base score 8.3)
CVSS v2: 6.8
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Nim-lang Nim
Published: 2021-03-26
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-21372?: 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.
How severe is CVE-2021-21372?: CVE-2021-21372 has a CVSS 3.x base score of 8.3, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-21372 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21372?: CVE-2021-21372 affects Nim-lang Nim. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21372?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-21372 published?: CVE-2021-21372 was published on 2021-03-26 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nim-lang:nim:*:*:*:*:*:*:*:*

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