Authentication bypass in TrueNAS SCALE HA heartbeat origin check

Authentication bypass in the HA heartbeat origin check in middlewared in TrueNAS SCALE before 25.10.8 (and in release trains before their respective fixes) allows an attacker on the same network segment to achieve unauthenticated full-administrator API access and execute commands as root. middlewared registers the HA peer-authentication hook (ha_permission) unconditionally, with no failover-licence or heartbeat-interface check. An unauthenticated connection whose TCP peer address is a hardcoded HA heartbeat address (169.254.10.1 or 169.254.10.2) and whose peer port is <= 1024 is granted a node credential that is authorized for every API method and treated as full administrator. Both conditions are properties of the attacker's own socket, and thus an attacker on the same layer-2 segment satisfies them without forging anything. The hook is present on non-HA, unlicensed, single-node Community Edition installations. The fix additionally requires that the connection terminate on the HA heartbeat listener (a local address/port the attacker cannot control).