What’s Vulnerable › Vulnerabilities

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.

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2022-01-14 · updated 2026-06-17
• Weakness: CWE-285

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.

Affected products

• Arista Networks EOS: before 4.20; from 4.21.0 through 4.21.14m; from 4.22.0 through 4.22.11m; from 4.23.0 through 4.23.8m; from 4.24.6.0 through 4.24.6m; from 4.25.0 through 4.25.4m — fixed in 4.20

How to fix

Upgrade to a fixed version: Arista Networks EOS 4.20. Check the vendor advisory for mitigations.

References

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

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