Are drop down select fields vulnerable to any sort

Question

I have read here the mantra "never trust user input" and it makes sense. I can understand that any field that is typed in by the user is suspect. However, what about drop down select fields? Can they be used for any type of injection?

I have sanitized all the fields that allow a user to type in, and also used mysqli prepared statements for insertion into the database.

However, there are three drop-downs in my form and was wondering if I need to do anything about them?

Answer 1

Many modern browsers come with the capability of source-modification. So yes, any client -> server information can be injection.

But if you're using bind variables for all $_POST or $_GET data, you should be fine.