How to upload a lot of pictures safely?

Question

CodeIgniter

Immediately to the point, there is a contact form in the frontend with the ability to upload images, there can be a large number of them, how to upload them safely so that the user cannot change something in the form through the element inspector if, for example, do hidden fields with value the image address?

Answer 1

The user can always " change something in the form through the element inspector by doing for example hidden fields with value image address ". Check all incoming data on the server, that's all security. What exactly to check and how depends on your code and business logic.