The white box is composed of three parts: 1. The first part is an input box with the label Input secret: 2. The second is a button named Submit query 3. The last is a link View sourcecode pointing to http://natas6.natas.labs.overthewire.org/index-source.html
Now if we just click on submit query, the page is refreshed and a message saying Wrong secret appears.
The link View sourcecode seems to display the server code (which is PHP).
<html>
<head>
<!−− This stuff in the header has nothing to do with the level −−>
<link rel="stylesheet" type="text/css" href="http://natas.labs.overthewire.org/css/level.css">
<link rel="stylesheet" href="http://natas.labs.overthewire.org/css/jquery−ui.css" />
<link rel="stylesheet" href="http://natas.labs.overthewire.org/css/wechall.css" />
<script src="http://natas.labs.overthewire.org/js/jquery−1.9.1.js"></script>
<script src="http://natas.labs.overthewire.org/js/jquery−ui.js"></script>
<script src=http://natas.labs.overthewire.org/js/wechall−data.js></script><script src="http://natas.labs.overthewire.org/js/wechall.js"></script>
<script>var wechallinfo = { "level": "natas6", "pass": "<censored>" };</script>
</head>
<body>
<h1>natas6</h1>
<div id="content">
<? include "includes/secret.inc";
if(array key exists("submit", $ POST)) {
if($secret == $ POST[’secret’]) {
print "Access granted. The password for natas7 is <censored>";
} else {
print "Wrong secret";
}
}
?>
<form method=post>
Input secret: <input name=secret><br>
<input type=submit name=submit>
</form>
<div id="viewsource"><a href="index−source.html">View sourcecode</a></div>
</div>
</body>
</html>We see that the variable $secret isn’t declared in the code. It must be declared in the include which is located in http://natas6.natas.labs.overthewire.org/includes/secret.inc. Navigating to this page only show a blank page. But if we look at the page source, here is what we see:
<?
$secret = "FOEIUWGHFEEUHOFUOIU";
?>Now we go back to the original page, enter this secret in the input box and click on Submit Query.
A message appears:
Access granted. The password for natas7 is 7z3hEENjQtflzgnT29q7wAvMNfZdh0i9