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.
CVE-2021-45707
CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence
This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 0.5%, top 35% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 2%CVSS: 9.8Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.8
- EG Score
- 9.8(medium)
- EPSS
- 73.8%
- KEV
- Not listed
Published
December 27, 2021
Last Modified
November 21, 2024
Advisory Details (3)
Auto-updated Jun 21, 2026Patch available. Sources: github.
generic
RUSTSEC-2021-0119: nix: Out-of-bounds write in nix::unistd::getgrouplist › RustSec Advisory Database
https://rustsec.org/advisories/RUSTSEC-2021-0119.htmlgithub Patch Available
Out-of-bounds write in nix::unistd::getgrouplist · GHSA-wgrg-5h56-jg27 · GitHub Advisory Database · GitHub
https://github.com/advisories/GHSA-wgrg-5h56-jg27Vendor Advisories for CVE-2021-45707(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Frequently asked(5)
What is CVE-2021-45707?
CVE-2021-45707 is a critical vulnerability published on December 27, 2021. 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.
When was CVE-2021-45707 disclosed?
CVE-2021-45707 was first published in the National Vulnerability Database on December 27, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-45707 actively exploited?
CVE-2021-45707 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 73.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-45707?
CVE-2021-45707 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2021-45707?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-45707, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2021-45707
Is Your Infrastructure Affected by CVE-2021-45707?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.