Need

Ensure the privacy and security of sensitive business information

Context

• Usage of Elixir (v1.11+) for building scalable and fault-tolerant applications
• Usage of Plug for creating middleware
• Usage of Phoenix Framework for web interface development

Description

Non compliant code

        defmodule UnsecuredController do
  use Phoenix.Controller

  def list_customers(conn, _params) do
    customers = Repo.all(Customer)
    render(conn, "index.html", customers: customers)
  end
end
        
        

This code retrieves all customer information from the database and renders it without any authentication or authorization check. This can lead to exposure of sensitive customer data, which can be used to craft new attack vectors.

Steps

• Use a middleware like Plug to handle authentication and authorization.
• Create a function to check if the user is authenticated and authorized before allowing access to the customer data.
• Wrap your sensitive routes with this middleware.

Compliant code

        defmodule SecuredController do
  use Phoenix.Controller

  plug :authenticate_user

  def list_customers(conn, _params) do
    customers = Repo.all(Customer)
    render(conn, "index.html", customers: customers)
  end

  defp authenticate_user(conn, _opts) do
    # Check if user is authenticated and authorized
    #... code ...
    # If not authenticated or authorized, redirect or send error response
    #... code ...
  end
end
        
        

This code checks if the user is authenticated and authorized before retrieving and rendering customer data. This prevents unauthorized users from accessing sensitive customer data.

References

• 080. Business information leak - Customers or providers