A vulnerability in Arista EOS affects platforms configured with both 802.1X port authentication and the RADIUS proxy feature using dynamic authorization. A low-privileged attacker on an adjacent network segment can induce a RADIUS packet through a configured RADIUS proxy client to block dynamic authorization messages, such as Change-of-Authorization and Disconnect-Requests, from being applied. This allows an endpoint session that should be disconnected by the RADIUS server or network access control system to remain authorized on the network. Both features must be explicitly configured for this issue to be exploitable. The vulnerability has a medium severity score and no known exploitation in the wild has been reported. No patch or remediation details are provided.