Apache NiFI 1.10.0 through 2.10.0 provide a Parameter Context update REST API method that does not enforce authorization checking on components referencing Parameter values. Updating a Parameter Context can change parameter values that affect referencing components, but framework authorization was limited to read and write privileges on the Parameter Context itself. As a result of the missing authorization, an authenticated user authorized to modify a Parameter Context, but not authorized on referencing components, could alter Parameter values affecting those components. In deployments where a Parameter value contains executable scripting content, updating a Parameter can result in code execution during automatic component validation, without starting the referencing component. The impact was limited to stopped components by existing verification checks, and the issue applies only to deployments that use component-level authorization policies. Upgrading to Apache NiFi 2.11.0 is the recommended mitigation, which aligns the Parameter Context update method authorization with other methods, adding authorization checking on affected components.

Apache NiFi 0.0.1 through 2.9.0 support building qualified URLs from one of several HTTP request headers that provide an alternative to the standard Host header without validating the values provided. Apache NiFi 1.6.0 introduced a configurable application property to restrict values provided in the HTTP Host header, but did not apply the validation to alternative Proxy and Forwarded headers. The absence of proxy host header validation allowed a client to instruct Apache NiFi web services to construct invalid qualified URLs for redirection or data references. Upgrading to Apache NiFi 2.10.0 is the recommended mitigation, which implements validation for the X-ProxyHost and X-Forwarded-Host HTTP request headers based on the nifi.web.proxy.host property. Enabling header validation requires configuring the application with HTTPS. Reverse proxy servers in front of Apache NiFi are responsible for filtering input request headers and providing allowed values to the application.

Improper escaping of database table names in the CaptureChangeMySQL Processor included with Apache NiFi 1.2.0 through 2.9.0 allows for injecting SQL commands using crafted naming. Manual quoted boundaries added in Apache NiFi 1.8.0 narrowed the scope of potential injection options, but did not cover additional strategies. Apache NiFi installations that do not use the CaptureChangeMySQL Processor are not subject to this vulnerability. Upgrading to Apache NiFi 2.10.0 is the recommended mitigation, which incorporates more robust identifier escaping.

Apache NiFi 1.13.0 through 2.2.0 includes the username and password used to authenticate with MongoDB in the NiFi provenance events that MongoDB components generate during processing. An authorized user with read access to the provenance events of those processors may see the credentials information. Upgrading to Apache NiFi 2.3.0 is the recommended mitigation, which removes the credentials from provenance event records.

Apache NiFi 1.10.0 through 2.0.0 are missing fine-grained authorization checking for Parameter Contexts, referenced Controller Services, and referenced Parameter Providers, when creating new Process Groups.

Creating a new Process Group can include binding to a Parameter Context, but in cases where the Process Group did not reference any Parameter values, the framework did not check user authorization for the bound Parameter Context. Missing authorization for a bound Parameter Context enabled clients to download non-sensitive Parameter values after creating the Process Group.

Creating a new Process Group can also include referencing existing Controller Services or Parameter Providers. The framework did not check user authorization for referenced Controller Services or Parameter Providers, enabling clients to create Process Groups and use these components that were otherwise unauthorized.

This vulnerability is limited in scope to authenticated users authorized to create Process Groups. The scope is further limited to deployments with component-based authorization policies. Upgrading to Apache NiFi 2.1.0 is the recommended mitigation, which includes authorization checking for Parameter and Controller Service references on Process Group creation.

Apache NiFi 1.16.0 through 1.28.0 and 2.0.0-M1 through 2.0.0-M4 include optional debug logging of Parameter Context values during the flow synchronization process. An authorized administrator with access to change logging levels could enable debug logging for framework flow synchronization, causing the application to write Parameter names and values to the application log. Parameter Context values may contain sensitive information depending on application flow configuration. Deployments of Apache NiFi with the default Logback configuration do not log Parameter Context values. Upgrading to Apache NiFi 2.0.0 or 1.28.1 is the recommendation mitigation, eliminating Parameter value logging from the flow synchronization process regardless of the Logback configuration.

Apache NiFi 1.10.0 through 1.27.0 and 2.0.0-M1 through 2.0.0-M3 support a description field for Parameters in a Parameter Context configuration that is vulnerable to cross-site scripting. An authenticated user, authorized to configure a Parameter Context, can enter arbitrary JavaScript code, which the client browser will execute within the session context of the authenticated user. Upgrading to Apache NiFi 1.28.0 or 2.0.0-M4 is the recommended mitigation.

Apache NiFi 1.10.0 through 1.26.0 and 2.0.0-M1 through 2.0.0-M3 support a description field in the Parameter Context configuration that is vulnerable to cross-site scripting. An authenticated user, authorized to configure a Parameter Context, can enter arbitrary JavaScript code, which the client browser will execute within the session context of the authenticated user. Upgrading to Apache NiFi 1.27.0 or 2.0.0-M4 is the recommended mitigation.

Apache NiFi 1.21.0 through 1.23.0 support JDBC and JNDI JMS access in several Processors and Controller Services with connection URL validation that does not provide sufficient protection against crafted inputs. An authenticated and authorized user can bypass connection URL validation using custom input formatting. The resolution enhances connection URL validation and introduces validation for additional related properties. Upgrading to Apache NiFi 1.23.1 is the recommended mitigation.

The JndiJmsConnectionFactoryProvider Controller Service, along with the ConsumeJMS and PublishJMS Processors, in Apache NiFi 1.8.0 through 1.21.0 allow an authenticated and authorized user to configure URL and library properties that enable deserialization of untrusted data from a remote location.

The resolution validates the JNDI URL and restricts locations to a set of allowed schemes.

You are recommended to upgrade to version 1.22.0 or later which fixes this issue.

Impact

org.apache.nifi.authentication.single.user.writer.StandardLoginCredentialsWriter contains a local information disclosure vulnerability due to writing credentials (username and password) to a file that is readable by all other users on unix-like systems. On unix-like systems, the system's temporary directory is shared between all users on that system. As such, files written to that directory without setting the correct file permissions can allow other users on that system to view the contents of the files written to those temporary files.

Source

An insecure temporary file is created here: - https://github.com/apache/nifi/blob/6a1c7c72d5b91b9ce5d5cb5b86e3155d21e2c19b/nifi-commons/nifi-single-user-utils/src/main/java/org/apache/nifi/authentication/single/user/writer/StandardLoginCredentialsWriter.java#L75

The username and password credentials are written to this file here: - https://github.com/apache/nifi/blob/6a1c7c72d5b91b9ce5d5cb5b86e3155d21e2c19b/nifi-commons/nifi-single-user-utils/src/main/java/org/apache/nifi/authentication/single/user/writer/StandardLoginCredentialsWriter.java#L85-L95

Patches

The vulnerability has been patched in version 1.16.

Prerequisites

This vulnerability impacts Unix-like systems, and very old versions of Mac OSX and Windows as they all share the system temporary directory between all users.

Workarounds

Setting the java.io.tmpdir system environment variable to a directory that is exclusively owned by the executing user will fix this vulnerability for all operating systems.

References

- https://issues.apache.org/jira/browse/NIFI-9785 - https://github.com/apache/nifi/commit/859d5fe - https://github.com/apache/nifi/pull/5856 - https://nifi.apache.org/security.html#CVE-2022-26850 - https://twitter.com/JLLeitschuh/status/1511736635645435904?s=20&t=I3w3zF6Y2DUvWYsEFqERjg

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.

Eclipse Jetty is vulnerable to a denial of service, caused by an error when handling a request containing multiple Accept headers with a large number of quality parameters. By sending a specially-crafted request, a remote attacker could exploit this vulnerability to exhaust minutes of CPU time.

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).

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.

An information disclosure vulnerability was found in Apache NiFi 1.10.0. The sensitive parameter parser would log parsed values for debugging purposes. This would expose literal values entered in a sensitive property when no parameter was present.

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.

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.

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.

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.

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.

In Apache NiFi before 1.0.1 and 1.1.x before 1.1.1, there is a cross-site scripting vulnerability in connection details dialog when accessed by an authorized user. The user supplied text was not being properly handled when added to the DOM.

An authorized user could upload a template which contained malicious code and accessed sensitive files via an XML External Entity (XXE) attack. The fix to properly handle XML External Entities was applied on the Apache NiFi 1.4.0 release. Users running a prior 1.x release should upgrade to the appropriate release.

In Apache NiFi before 0.7.4 and 1.x before 1.3.0, there are certain user input components in the UI which had been guarding for some forms of XSS issues but were insufficient.