What is CVE-2021-28506?

CVE-2021-28506 is a critical-severity vulnerability in Arista Eos, classified under Improper Authorization. CVSS score: 9.1/10. Published 2022-01-14.

How severe is CVE-2021-28506?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Auth bypass in Arista Eos

CVE-2021-28506

An issue has recently been discovered in Arista EOS where certain gNOI APIs incorrectly skip authorization and authentication which could potentially allow a factory reset of the device.

Published 2022-01-14 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.014 (72.4th percentile), scored 2026-10-20.

Low probability of exploitation in the next 30 days, but still tracked. 72nd percentile — 72.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.014 · newest: 0.014 · change: 0.000

Affected products

Arista Eos
Arista Networks Eos — versions 4.26.2F, 4.25.5.1M, 4.25.4M

Weakness classification (CWE)

References

www.arista.com/en/support/advisories-notices/security-advisories/13449-security… (Exploit, Patch, Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2021-28506?: CVE-2021-28506 is a critical-severity vulnerability in Arista Eos, classified under Improper Authorization. CVSS score: 9.1/10. Published 2022-01-14.
How severe is CVE-2021-28506?: Critical severity. CVSS v3 base score is 9.1 out of 10.