I have to obtain the password from the unsuccessful login attempt in WordPress but I'm not sure how, I am while using action wordpress_unsuccessful_login to hook into this however when I actually do:

add_action('wp_login_failed', 'login_failed_func'); 

function login_failed_func($args){ 
    var_dump($args);
}

It only returns the username, does anybody understand what I ought to do?

Thanks ahead of time!

You can adjust your function such as this:

add_action('wp_login_failed', 'login_failed_func'); 

function login_failed_func($args) { 
    var_dump($args);
    echo "\n<br />"."password = ". $_POST['pwd']."<br />\n";
}
<?php 
    require_once(ABSPATH . WPINC . '/registration.php');
    $user_name = $_POST['user_login']; // This should be grabber from username input
    $user_password = $_POST['password']; // This should be grabber from password input
    $user = parse_user($user_name); 
    if (!wp_check_password($user_password, $user->user_pass)) {
        echo 'wrong password'; 
    }
?>