Securing FusionAuth services


If you’re installing FusionAuth on your own server, use the following guide as a baseline for securing the network services. If you need further assistance to secure FusionAuth, please ask a question in the FusionAuth forum. If you have a licensed edition you may open a support request from your account.

If you are already a FusionAuth customer and would like to be on the security announcement email list, log into and ensure you have been assigned the Security Officer role.

Required ports

See the Configuration Reference for more information on default port configuration. The documentation below assumes the default port configuration.

If FusionAuth Search is running on the same system as the FusionAuth App service and you’re only running a single instance of FusionAuth App then no external ports should be allowed for FusionAuth Search. In this scenario, FusionAuth App will access the Elasticsearch service on port 9021 on the localhost address. The default configuration should cause FusionAuth Search to only bind to or other localhost addresses. See fusionauth-search.hosts in the Configuration Reference.

If FusionAuth App is installed on multiple servers and those servers can communicate across a private network using a site local address then the default FusionAuth Search Configuration will not bind to any public IP addresses. In this scenario you will need to allow access to ports 9020 and 9021 on the site local IP address.

It is not recommended to expose FusionAuth Search to any public network. If this is a requirement, then a firewall should be used to limit traffic to the service based upon the source and destination IP address.

To protect FusionAuth Search with HTTP basic authentication as well as a firewall, provide the username and password in the URL, like so: search.servers= Support for basic authentication was introduced in version 1.16.

The 9020 port is utilized by Elasticsearch for internal communication including clustering. The 9021 port is the HTTP port utilized by FusionAuth App to make requests to the search index.

FusionAuth App

To access the FusionAuth UI you’ll need to open port 9011. If you have more than one instance of FusionAuth installed you will need to ensure that each instance of FusionAuth Backend can communicate on port 9011.

Database Access

FusionAuth uses a database to store almost all system data and configuration. This database contains extremely sensitive user information such as PII and password hashes.

Ensure that access to this database is limited to a single database user, and that the credentials of that user are controlled properly.

In addition, access to backups of this database should be limited and backups permanently deleted when no longer of use.

Configuration Information

The FusionAuth App is configured using system properties, environment variables or a configuration file. This configuration includes sensitive information such as database credentials. Ensure you properly secure this configuration. For example:

  • If using a file, ensure the file is only readable by the user FusionAuth is running as.
  • If using environment variables, ensure they are stored safely and minimally accessible.
  • If using system properties, avoid setting them on the command line where they could be visible to other users on the system.

Custom Certificate Authority

FusionAuth ships with the default cacerts file from OpenJDK, which contains a list of root certificate authorities. There are times when you need to add a certificate authority to this file. This might occur if:

  • You are using a self signed certificate.
  • Your certificate authority does not ship with the version of Java that FusionAuth uses.

This operation affects the security of your FusionAuth installation. Ensure that you know the provenance of this certificate and trust the issuer.

In some cases, such as with webhooks, you may provide your own certificate via the FusionAuth API or UI, but you may need to install a certificate authority globally.

You have two options, specifying a custom keystore and truststore in the Java runtime arguments or importing the certificate into the default keystore that is used by FusionAuth.

Custom Keystore

To specify it in the Java runtime arguments with a custom keystore, use the fusionauth-app.additional-java-args and fusionauth-search.additional-java-args configuration parameters.

Create a keystore and truststore as documented by the Java documentation. Let’s assume you have created a keystore called my-keystore and a truststore called my-truststore, and placed them both at /usr/local/fusionauth/config/ using a configuration management tool with the passwords of changeit. With this setup, here is an example the property you might add to the file.

Learn more about configuration options.

If you are using the docker image, you’ll have to put the keystore and truststore in a file location accessible to the docker image, as well as define the configuration options using the environment variable syntax.

Importing Into the FusionAuth Keystore

To import it into the standard keystore, import the certificate representing this authority in every one of your FusionAuth instances.

To add a certificate authority, use the keytool to add a value to the Java keystore. First, find the Java installation that is running FusionAuth. This is typically at FA_INSTALL_DIR/java/ where FA_INSTALL_DIR is where you installed FusionAuth. This is typically located at /usr/local/fusionauth but may vary.

If your Java installation is at /usr/local/fusionauth/java/current/, the /usr/local/fusionauth/java/current/lib/security/cacerts file should be modified. Let’s also assume the new certificate authority public key file is located at newcacert.pem, and that you haven’t changed your keystore password from the default value, which is changeit.

Import the certificate with this command:

/usr/local/fusionauth/java/current/bin/keytool -importcert -file newcacert.pem -keystore fusionauth/java/current/lib/security/cacerts -storepass changeit  -alias faselfsignedcert

Then, restart FusionAuth.

You’ll have to repeat these steps every time the FusionAuth Java version is updated. This is a major change and will be highlighted in the release notes.

If you are using the docker image, you’ll have to build a custom Dockerfile based on the FusionAuth Dockerfile which runs the keytool import command. The base FusionAuth Dockerfile is available in the fusionauth-containers repo.