Apache NiFi 0.7.0 through 1.23.2 include the JoltTransformJSON Processor, which provides an advanced configuration user interface that is vulnerable to DOM-based cross-site scripting. If an authenticated user, who is authorized to configure a JoltTransformJSON Processor, visits a crafted URL, then arbitrary JavaScript code can be executed within the session context of the authenticated user. Upgrading to Apache NiFi 1.24.0 or 2.0.0-M1 is the recommended mitigation.

Apache NiFi 0.0.2 through 1.22.0 include Processors and Controller Services that support HTTP URL references for retrieving drivers, which allows an authenticated and authorized user to configure a location that enables custom code execution. The resolution introduces a new Required Permission for referencing remote resources, restricting configuration of these components to privileged users. The permission prevents unprivileged users from configuring Processors and Controller Services annotated with the new Reference Remote Resources restriction. Upgrading to Apache NiFi 1.23.0 is the recommended mitigation.

The DBCPConnectionPool and HikariCPConnectionPool Controller Services in Apache NiFi 0.0.2 through 1.21.0 allow an authenticated and authorized user to configure a Database URL with the H2 driver that enables custom code execution. The resolution validates the Database URL and rejects H2 JDBC locations. You are recommended to upgrade to version 1.22.0 or later which fixes this issue.

Multiple components in Apache NiFi 0.0.1 to 1.16.0 do not restrict XML External Entity references in the default configuration. The Standard Content Viewer service attempts to resolve XML External Entity references when viewing formatted XML files. The following Processors attempt to resolve XML External Entity references when configured with default property values: - EvaluateXPath - EvaluateXQuery - ValidateXml Apache NiFi flow configurations that include these Processors are vulnerable to malicious XML documents that contain Document Type Declarations with XML External Entity references. The resolution disables Document Type Declarations in the default configuration for these Processors, and disallows XML External Entity resolution in standard services.

In the TransformXML processor of Apache NiFi before 1.15.1 an authenticated user could configure an XSLT file which, if it included malicious external entity calls, may reveal sensitive information.

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 NiFi download token (one-time password) mechanism used a fixed cache size and did not authenticate a request to create a download token, only when attempting to use the token to access the content. An unauthenticated user could repeatedly request download tokens, preventing legitimate users from requesting download tokens.

In Apache NiFi 1.10.0 to 1.11.4, the NiFi stateless execution engine produced log output which included sensitive property values. When a flow was triggered, the flow definition configuration JSON was printed, potentially containing sensitive values in plaintext.

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.

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.

The template upload API endpoint accepted requests from different domain when sent in conjunction with ARP spoofing + man in the middle (MiTM) attack, resulting in a CSRF attack. The required attack vector is complex, requiring a scenario with client certificate authentication, same subnet access, and injecting malicious code into an unprotected (plaintext HTTP) website which the targeted user later visits, but the possible damage warranted a Severe severity level. Mitigation: The fix to apply Cross-Origin Resource Sharing (CORS) policy request filtering was applied on the Apache NiFi 1.8.0 release. Users running a prior 1.x release should upgrade to the appropriate release.

When a client request to a cluster node was replicated to other nodes in the cluster for verification, the Content-Length was forwarded. On a DELETE request, the body was ignored, but if the initial request had a Content-Length value other than 0, the receiving nodes would wait for the body and eventually timeout. Mitigation: The fix to check DELETE requests and overwrite non-zero Content-Length header values was applied on the Apache NiFi 1.8.0 release. Users running a prior 1.x release should upgrade to the appropriate release.

The message-page.jsp error page used the value of the HTTP request header X-ProxyContextPath without sanitization, resulting in a reflected XSS attack. Mitigation: The fix to correctly parse and sanitize the request attribute value was applied on the Apache NiFi 1.8.0 release. Users running a prior 1.x release should upgrade to the appropriate release.

The X-Frame-Options headers were applied inconsistently on some HTTP responses, resulting in duplicate or missing security headers. Some browsers would interpret these results incorrectly, allowing clickjacking attacks. Mitigation: The fix to consistently apply the security headers was applied on the Apache NiFi 1.8.0 release. Users running a prior 1.x release should upgrade to the appropriate release.

Apache NiFi JMS Deserialization issue because of ActiveMQ client vulnerability. Malicious JMS content could cause denial of service. See ActiveMQ CVE-2015-5254 announcement for more information. The fix to upgrade the activemq-client library to 5.15.3 was applied on the Apache NiFi 1.6.0 release. Users running a prior 1.x release should upgrade to the appropriate release.

Apache NiFi External XML Entity issue in SplitXML processor. Malicious XML content could cause information disclosure or remote code execution. The fix to disable external general entity parsing and disallow doctype declarations was applied on the Apache NiFi 1.6.0 release. Users running a prior 1.x release should upgrade to the appropriate release.

Any authenticated user (valid client certificate but without ACL permissions) could upload a template which contained malicious code and caused a denial of service via Java deserialization attack. The fix to properly handle Java deserialization was applied on the Apache NiFi 1.4.0 release. Users running a prior 1.x release should upgrade to the appropriate release.

A malicious X-ProxyContextPath or X-Forwarded-Context header containing external resources or embedded code could cause remote code execution. The fix to properly handle these headers was applied on the Apache NiFi 1.5.0 release. Users running a prior 1.x release should upgrade to the appropriate release.