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Understanding "Safe" Validation Rules
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After all, if the developer configures the form with certain fields, shouldn't they all just be copied to the `$model` after validation has passed? Why isn't this good enough?Because Yii is protecting you from security surprises.
Though it may seem obvious to accept all the fields built into a form, during the controller's action (where Massive Assignment is taking place), Yii has no way of knowing which actual fields were part of a the form. and which are from a bad guy who is **synthesizing** form input with a contrived POST in order to fool the application.
This is protecting against two scenarios:
1. Some models have attributes that are legitimate (in general), but not in a specific form. For instance, a change-your-password form for a user should accept the `password` and `passwordRepeat` attributes, but not the `isAdmin` attribute that makes him an administrator of the application. For a changePassword scenario, isAdmin should be marked explicitly `'unsafe'`.
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