Question

I am learning sql injections and very interested how to cause this.
I have written script to see how it is going. so here is my code =>

if (isset($_POST['act'])){
    if ($connection = mysqli_connect($var['host'],$var['user'],$var['password'],$var['database'])){
        if (mysqli_connect_errno()==0){
            $username = $_POST['username'];
            $password = $_POST['pswd'];
            if ($result = mysqli_query($connection,"SELECT username,password FROM login WHERE username='" . $username . "' AND password='" . $password . "'")){
                if (mysqli_num_rows($result)){
                    header("Location: http://localhost/default.php");
                } else {
                    $res = "Invalid Credentials ...";
                }
            }
        }
    }
}

<form name="action" method="post" action="index.php">
    Username:<input type="text" name="username" size="12"><br>
    Password:<input type="password" name="pswd" size=12><br>
    <input type="submit" name="act" value="Login">
</form>

I’m writing like this in forms, but nothing happening

in username and in password form => some’ OR ‘1’=’1′

I’m very interested how to cause sql injection to break this script and without valid credentials redirect to default.php (of course within from marked script)

Thanks …

Answer 1

Try entering ' OR 1 -- as username

Also, just in case, chack if you have magic_quotes_gpc disabled 🙂