An interesting task in PHP

Question

PHP

I liked one of the tasks from one of the latest CTFs for its simplicity, I suggest breaking your head a little.
There is an executable script:

<?php
    $key = "KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK";
    $pass = "KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK";
    if ( strcasecmp( $_GET['pass'], $pass ) == 0 ) {
        echo($key);
    }
?>

Actually the question is in obtaining the key, how to do it?
Where is the vulnerability that many of us tend to leave behind?

Answer 1

?pass[]=something

Answer 2

Oh may may, what a cant in PHP, I immediately remember another confusion in the return values ​​​​in strpos () when it can return 0 or false

Answer 3

I'm afraid many do not check the type of input parameters in GET.

Answer 4

Here's another question for you then. If you do this:
switch( $_GET['pass'] ) { // ... }
do you need to check $_GET['pass']?