CVE-2021-45707

Name: CVE-2021-45707
Creator: NVD / NIST
Published: 2021-12-27T00:15:09.94+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 1.64%

Last modified Jun 17, 2026

CVE-2021-45707 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. An issue was discovered in the nix crate 0.16.0 and later before 0.20.2, 0.21.x before 0.21.2, and 0.22.x before 0.22.2 for Rust. unistd::getgrouplist has an out-of-bounds write if a user is in more than 16 /etc/groups groups.. EPSS estimates a 1.64% chance of exploitation in the next 30 days.

Description

An issue was discovered in the nix crate 0.16.0 and later before 0.20.2, 0.21.x before 0.21.2, and 0.22.x before 0.22.2 for Rust. unistd::getgrouplist has an out-of-bounds write if a user is in more than 16 /etc/groups groups.

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

1.64%

73.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
Nix Project	Nix	>= 0.16.0, < 0.20.2
Nix Project	Nix	>= 0.21.0, < 0.21.2
Nix Project	Nix	>= 0.22.0, < 0.22.2

References

https://github.com/advisories/GHSA-wgrg-5h56-jg27Third Party Advisory
https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/nix/RUSTSEC-2021-0119.mdThird Party Advisory
https://rustsec.org/advisories/RUSTSEC-2021-0119.htmlIssue Tracking, Third Party Advisory
https://github.com/advisories/GHSA-wgrg-5h56-jg27Third Party Advisory
https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/nix/RUSTSEC-2021-0119.mdThird Party Advisory
https://rustsec.org/advisories/RUSTSEC-2021-0119.htmlIssue Tracking, Third Party Advisory

Timeline

Published: Dec 27, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-45707?

How severe is CVE-2021-45707?

CVE-2021-45707 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.64% probability of exploitation in the next 30 days.

How do I fix CVE-2021-45707?

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-2021-45707?

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

Scan your code now

Source: NVD / NIST