This vulnerability (CVE-2024-6858) in Arista EOS involves improper validation of input types (CWE-1287) when the device is configured in 802.1X mode. Specifically, multi-authentication unauthenticated hosts may be granted access to a switch port if there is an EAPOL capable device present in the fallback VLAN. This could allow unauthorized hosts to bypass intended network access controls. The CVSS 3.1 base score is 6.5 (medium severity) with attack vector as adjacent network, low attack complexity, no privileges required, no user interaction, unchanged scope, no confidentiality impact, high integrity impact, and no availability impact. The affected versions explicitly include 4.28.10, 4.29.0, 4.30.0, and 4.31.0. There is no vendor advisory or patch information available at this time.

The vulnerability allows multi-authentication unauthenticated hosts to potentially gain unauthorized access to switch ports in 802.1X mode if an EAPOL capable device exists in the fallback VLAN. This can lead to integrity violations on the network by permitting unauthorized devices to connect and potentially manipulate network traffic or configurations. There is no reported impact on confidentiality or availability.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, administrators should carefully review 802.1X and fallback VLAN configurations to minimize exposure. No official remediation or temporary fix has been provided by Arista Networks as of the current information.