How severe is CVE-2021-28500?

CVE-2021-28500 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.

Is CVE-2021-28500 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-28500?

CVE-2021-28500 affects Arista Eos. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-28500?

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

When was CVE-2021-28500 published?

CVE-2021-28500 was published on 2022-01-14 and last updated on 2026-06-17.

CVE-2021-28500

CVE-2021-28500 is a critical-severity vulnerability in Arista Eos with a CVSS 3.x base score of 9.1. 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-285.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 6.9
EPSS exploit prediction: 1% (54th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-285
Affected product: Arista Eos
Published: 2022-01-14
Last modified: 2026-06-17

Description

An issue has recently been discovered in Arista EOS where the incorrect use of EOS's AAA API’s by the OpenConfig and TerminAttr agents could result in unrestricted access to the device for local users with nopassword configuration.

Frequently asked questions

What is CVE-2021-28500?: An issue has recently been discovered in Arista EOS where the incorrect use of EOS's AAA API’s by the OpenConfig and TerminAttr agents could result in unrestricted access to the device for local users with nopassword configuration.
How severe is CVE-2021-28500?: CVE-2021-28500 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.
Is CVE-2021-28500 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-28500?: CVE-2021-28500 affects Arista Eos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-28500?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-28500 published?: CVE-2021-28500 was published on 2022-01-14 and last updated on 2026-06-17.

References

https://www.arista.com/en/support/advisories-notices/security-advisories/13449-security-advisory-0071

Affected products (1)

cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*

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