Insecure object reference - Scala

Insecure object reference - Scala

Need

Enforce proper access controls to prevent unauthorized access to sensitive data

Context

  • Usage of Scala 2.12 for developing scalable and high-performance applications
  • Usage of play-json for JSON parsing and serialization in Play Framework
  • Usage of Play framework for building web applications
  • Usage of play-slick for integrating the Slick database library with the Play Framework
  • Usage of Slick for Database Querying and ORM

Description

Non compliant code

        def getUser(id: String) = Action {
  User.findById(id).map { user =>
    Ok(Json.toJson(user))
  }.getOrElse(NotFound)
}

The above code demonstrates an insecure direct object reference (IDOR) vulnerability. This is a common issue in web applications that expose object references to users.

In this case, the getUser function in a Play Framework controller is allowing any user to retrieve any User object, simply by providing the user's ID. The findById function is directly using the ID provided in the request to fetch the user data from the database, without any check to confirm whether the requester has the necessary permissions to access this data.

This means that if an attacker can guess or otherwise obtain a valid user ID, they can use this function to retrieve that user's data, even if they should not have access to it. This is a serious security issue, as it could allow unauthorized access to sensitive user data.

The vulnerability could be exploited by an attacker simply by making a request to the getUser endpoint with the ID of a user they wish to target. Because there is no authorization check in place, the server would respond with the targeted user's data, regardless of who made the request.

Steps

  • Implement proper authentication and authorization mechanisms to ensure that only authorized users can access the getUser endpoint.
  • Use session management or token-based authentication to authenticate users and associate their identity with their requests.
  • Ensure that the user making the request has the necessary permissions to access the requested user's data.
  • Avoid using insecure identifiers, such as user IDs, directly in the API endpoints. Instead, use a more secure and unique identifier, such as a randomly generated token or a UUID.
  • Implement access control checks within the getUser endpoint to verify that the authenticated user has the necessary privileges to access the requested user's data.
  • Consider implementing a role-based access control (RBAC) system to manage user permissions and restrict access to sensitive data.
  • Regularly review and update the authorization mechanisms to address any new vulnerabilities or security risks that may arise.
  • Perform thorough testing and security audits to identify and fix any potential security vulnerabilities in the application.

Compliant code

        def getUser = Action { implicit request =>
  request.session.get("userId").flatMap { userId =>
    User.findById(userId).map { user =>
      Ok(Json.toJson(user))
    }
  }.getOrElse(Unauthorized)
}

The updated code now includes a session-based authentication mechanism. The getUser function no longer takes an id parameter directly from the request. Instead, it retrieves the userId from the session data associated with the request. This userId is then used to find the corresponding user in the database.

The request.session.get("userId") function attempts to retrieve the userId from the session data. If the userId is not found in the session data (i.e., the user is not authenticated), the function returns None and the getOrElse function is called, returning an Unauthorized response.

If the userId is found in the session data, the flatMap function is called to find the corresponding user in the database. If the user is found, the Ok(Json.toJson(user)) function is called to return the user's data as a JSON response. If the user is not found, the getOrElse function is called, returning a NotFound response.

This approach ensures that only authenticated users can access the getUser endpoint and that users can only access their own data. It also avoids the use of insecure identifiers, such as user IDs, directly in the API endpoints.

To further enhance the security of the application, consider implementing a role-based access control (RBAC) system to manage user permissions and restrict access to sensitive data. Regularly review and update the authorization mechanisms to address any new vulnerabilities or security risks that may arise. Perform thorough testing and security audits to identify and fix any potential security vulnerabilities in the application.

References