Description:
------------
<?php
$to      = 'nobody@example.com';
$subject = 'the subject';
$message = 'hello';
$headers = 'From: someoneelse@example.com' . "\r\n" .
    'Reply-To: webmaster@example.com' . "\r\n" .
    'X-Mailer: PHP/' . phpversion();

mail($to, $subject, $message, $headers);
?>
One can mail anyone using someone else's email address without authentication. No password is required.   
$to = 'anybody@example.com'
'From: someoneelse@example.com'


"SERIOUS SECURITY ISSUE"
Bug detected By: DEVESH GOYAL

Expected result:
----------------
Must ask for password for the email address which is used in 
'From: someoneelse@example.com'


"SERIOUS SECURITY ISSUE"
Bug detected By: DEVESH GOYAL