CVE-2021-28503 Auth bypass in Arista EOS

High 7.4 Published 4 Feb 2022 Updated 16 Sep 2024

Remote attackers can bypass authentication and access Arista EOS devices via eAPI when certificate-based authentication is configured.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-28503?

CVE-2021-28503 is a high-severity authentication bypass vulnerability in Arista EOS, published on 4 Feb 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The impact of this vulnerability is that Arista's EOS eAPI may skip re-evaluating user credentials when certificate based authentication is used, which allows remote attackers to access the device via eAPI.

Weakness: CWE-287, CWE-305

Which versions are affected by CVE-2021-28503?

It affects 1 product.

Products include Arista Eos.

How do I fix CVE-2021-28503?

No fix has been published for CVE-2021-28503 yet. Limit exposure of the affected software until one is available.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2021-28503 being exploited?

There is no known exploitation of CVE-2021-28503 in the wild and no public exploit code.

Sources

Also known as GHSA-mvw4-rrm9-fqfc.