In Apache NiFi 1.2.0 to 1.11.4, the NiFi UI and API were protected by mandating TLS v1.2, as well as listening connections established by processors like ListenHTTP, HandleHttpRequest, etc. However intracluster communication such as cluster request replication, Site-to-Site, and load balanced queues continued to support TLS v1.0 or v1.1.
In Apache NiFi 1.0.0 to 1.11.4, the notification service manager and various policy authorizer and user group provider objects allowed trusted administrators to inadvertently configure a potentially malicious XML file. The XML file has the ability to make external calls to services (via XXE).
In Apache NiFi 0.0.1 to 1.11.0, the flow fingerprint factory generated flow fingerprints which included sensitive property descriptor values. In the event a node attempted to join a cluster and the cluster flow was not inheritable, the flow fingerprint of both the cluster and local flow was printed, potentially containing sensitive values in plaintext.
A XSS vulnerability was found in Apache NiFi 1.0.0 to 1.10.0. Malicious scripts could be injected to the UI through action by an unaware authenticated user in Firefox. Did not appear to occur in other browsers.
The XMLFileLookupService in NiFi versions 1.3.0 to 1.9.2 allowed trusted users to inadvertently configure a potentially malicious XML file. The XML file has the ability to make external calls to services (via XXE) and reveal information such as the versions of Java, Jersey, and Apache that the NiFI instance uses.
When updating a Process Group via the API in NiFi versions 1.3.0 to 1.9.2, the response to the request includes all of its contents (at the top most level, not recursively). The response included details about processors and controller services which the user may not have had read access to.
When using an authentication mechanism other than PKI, when the user clicks Log Out in NiFi versions 1.0.0 to 1.9.2, NiFi invalidates the authentication token on the client side but not on the server side. This permits the user's client-side token to be used for up to 12 hours after logging out to make API requests to NiFi.