title: Grails Prevent HTML modifications
body: <p>I'm looking for a way to prevent HTML form user modifications, based on this example:</p>
  
  <p>"User" entity has an enum Role (User, Administrator etc.) and there's a UserController that displays a g:form for first, last and email. Controller's action does user.properties = params.</p>
  
  <p>How, a user can modify the HTML form with Firebug or Chrome Webdeveloper and rename textfield firstname to role and enter "Administrator" and will be granted Administrator rights.</p>
  
  <p>There's useToken="true" and the withForm-closure, but this just seems to prevent the user to double-submit the same form. Beside this works with sessions and it's therefore not really scalable over multiple servers.</p>
  
  <p>I'm using Grails 2.3.6. Is there a way to prevent such things except not using xxx.properties = params?</p>