A gNMI Set request can be accepted by Arista EOS devices even when the OpenConfig interface should have rejected it because the request lacked the proper authentication for a critical function. This flaw allows an attacker who can reach the gNMI API to push arbitrary configuration changes to the switch, potentially disabling network services, altering routing tables, or compromising security settings. The weakness is a missing authentication for critical functions (CWE‑306).

Arista Networks EOS devices that have OpenConfig enabled are vulnerable. All releases in the 4.31.x, 4.30.x, 4.29.x, and 4.28.x trains are affected, with remediation available by upgrading to at least 4.31.3M, 4.30.6M, 4.29.8M, or 4.28.11M respectively. For earlier releases such as 4.30.5, 4.29.7, and 4.28.10.1, a specific hotfix SWIX package has been provided by Arista.

The CVSS score of 7.2 rates this vulnerability as high. No EPSS score is available, and it is not listed in the CISA KEV catalog. The likely attack vector is remote over the gNMI gRPC interface, potentially over TLS if SSL profiles are enabled. An attacker who can reach this interface, especially with valid credentials for the gNMI service, could exploit the missing authentication to push unauthorized configuration changes, leading to service disruption or denial of network infrastructure.