Apigee supply a custom Drupal module for the Developer Portal. Can you provide an assurance that the functionality within this module or set of modules is protected against Cross-site request forgery (CSRF or XSRF).
For example, the Drupal Form API provides protection against CSRF using special tokens in the forms which are added automatically. If a module uses the Form API for all requests that modify data and if you properly follow the Form API documentation then the module is protected from CSRF.