Protect mass assignment
06 Mar 2012
Last weekend github is hacked because of mass assignment issue, actually it's not rails fault, it's a "junior" develop forgot to add attr_accessible or attr_protected to model, like
class User < ActiveRecord::Base end class UsersController < ApplicationController def update if current_user.update_attributes(params[:user]) # do something end end end
if hacker can pass params[:user][:role] = 'admin', he may get admin privilege and do anything in your system, it's horrible.
Rails provides methods attr_accessible and attr_protected to solve this issue, but developers are too lazy and always forget to add them to models. If the way to solve security issue is not default, it is not security. Just like how rails3 solve XSS issue, rails should make it default way to protect attributes. Before rails do it, we should add attr_accessible or attr_protected to all models.
class User < ActiveRecord::Base attr_accessible :email, :password, :password_confirmation, :remember_me end
From rails 3.1, a new configuration is introduced
config.active_record.whitelist_attributes = true
It will create an empty whitelist of attributes available for mass-assignment for all models in your app.
It's important to protect your system, don't be lazy any more.