What is SQL Injection ?
SQL Injection is a attack against websites / web applications which are using SQL Database.
Simply, Hacker will insert malicious SQL command and takeover the database.
How Does it Work?
Let's say, You have a code like this,
<?php
$username = $_POST['username'];
$password = md5($_POST['password']);
$sql = "SELECT * FROM `users` WHERE username = '$username' AND password = '$password'";
?>
If user input,
Username : admin
Password : admin123
The SQL will looks like,
SELECT * FROM `users` WHERE username = 'admin' AND password = '0192023A7BBD73250516F069DF18B500'
It will works fine,
But If user input,
If your input,
Username : admin' OR 1 = 1 --
Password : admin123
The SQL will looks like,
SELECT * FROM `users` WHERE username = 'admin' OR 1 = 1 --' AND password = '0192023A7BBD73250516F069DF18B500'
Here you can see, The password query will be commented (Will not Execute).
And 1 = 1 is always true, The hacker can get all the information of Users.
They can delete or change any record too.
Click Here | Watch SQl Injection tutorial
SQL Injection Strings
Click Here | Some injection Strings
How to prevent SQL Injections?
Nowadays, Most of the back-end frameworks handle injections itself. But If you don't use any frameworks, You can do it manually.
Every language has built-in functions for handle SQL injections while binding data.
