In Apache NiFi before 0.7.2 and 1.x before 1.1.2 in a cluster environment, if an anonymous user request is replicated to another node, the originating node identity is used rather than the "anonymous" user.

In Apache NiFi before 0.7.2 and 1.x before 1.1.2 in a cluster environment, the proxy chain serialization/deserialization is vulnerable to an injection attack where a carefully crafted username could impersonate another user and gain their permissions on a replicated request to another node.