Girder maintains data security through a variety of mechanisms.

Default Authorization

Internally, endpoints default to requiring administrator permissions in order to use them. This means that, for example, when writing a plugin, a developer must consciously choose to allow non-administrator access. Basic administrator, user, or token access restrictions are applied before any other endpoint code is executed.

CORS (Cross-Origin Resource Sharing)

In an out-of-the-box Girder deployment, CORS is disabled for API calls. If you want your server to support API calls that are cross-origin requests from web browsers, you’ll need to modify some configuration settings.

As an administrator, go to the Admin console, then to Server configuration. Open the Advanced Settings panel and you will see several settings that allow you to specify the CORS policies for the REST API. The most important setting is the CORS Allowed Origins field, which is used to specify what origins are allowed to make cross-origin requests to the instance’s REST API. By default, this is blank, meaning no cross-origin requests are allowed. To allow requests from any origin, simply set this to *. You can also specify this as a comma-separated list of explicit origins to allow. If the Origin header occurs in this explicit list, the Access-Control-Allow-Origin header of the response will be set to the request’s Origin header value. You may also specify both * and a white list of explicit origins to allow. In this case, the response header will be set to the Origin header if it is explicitly listed, otherwise it will be set to *.

If you want more fine-grained control over the CORS policies, you can also restrict the allowed methods and allowed request headers by providing them in comma-separated lists in the CORS Allowed Methods and CORS Allowed Headers fields, though this is usually not necessary–the default values for these two fields are quite permissive and should enable complete access to the web API so long as the origin is allowed.

These settings simply control the CORS headers that are sent to the browser; actual enforcement of the CORS policies takes place on the user’s browser.

Database Injection Attacks

Girder defends against database injection attacks by using PyMongo as the only pathway between the application server and the database server. This protects against many injection vulnerabilities as described in the MongoDB Documentation. Girder also uses a model layer to mediate and validate all interaction with the database. This ensures that for all database operations, structural attributes (collection name, operation type, etc.) are hardcoded and not modifiable by the client, while data attributes (stored content) are validated for proper form before being accepted from a client.

Additionally, we strongly recommend configuring your MongoDB server with JavaScript disabled unless explicitly needed for your Girder-based application or plugin. Again, see the MongoDB Documentation for more information.

Session Management

Girder uses session management performed through the Girder-Token header or through a token passed through a GET parameter. This token is provided to the client through the cookie and expires after a configurable amount of time. In order to prevent session stealing, it is highly recommended to run Girder under HTTPS.

Cross-Site Scripting (XSS)

In order to protect against XSS attacks, all input from users is sanitized before presentation of the content on each page. This is handled by the template system Girder uses (Pug). This sanitizes user-provided content.

Cross-Site Request Forgery (CSRF)

To prevent CSRF attacks, Girder requires the Girder-Token parameter as a header for all state-changing requests. This token is taken from the user’s cookie and then passed in the request as part of the Girder one-page application and other clients such that the cookie alone is not enough to form a valid request. A sensible CORS policy (discussed above) also helps mitigate this attack vector.

Dependent Libraries

Another common attack vector is through libraries upon which Girder depends such as Cherrypy, Pug, PyMongo, etc. Girder’s library dependencies reference specific versions, ensuring that arbitrary upstream changes to libraries are not automatically accepted into Girder’s environment. Conversely, during development and before releases we work to ensure our dependencies are up to date in order to get the latest security fixes.

Notes on Secure Deployment

It is recommended that Girder be deployed using HTTPS as the only access method. Additionally, we recommend encrypting the volume where the Mongo database is stored as well as always connecting to Mongo using authenticated access. The volume containing any on-disk assetstores should also be encrypted to provide encryption of data at rest. We also recommend using a tool such as logrotate to enable the audit of Girder logs in the event of a data breach. Finally, we recommend a regular (and regularly tested) backup of the Girder database, configuration, and assetstores. Disaster recovery is an important part of any security plan.