查询字符串安全性和变量插值

Question

Not very familiar with PHP, is it possible for the user to take advantage of variable interpolation to get the value of secret?

<?php 
    $secret = 'hidden data';
    echo $_GET['id'];
?> 

I tried passing in for the id: $secret, %24secret, ${secret}, {$secret}, %7D%24secret%7D, %24%7Dsecret%7D. So far it seems safe, but just want to make sure I am not missing anything. Thanks in advance.

Answer 1

No, it's impossible for a user to retrieve hard-coded strings in this way.