Doubt in MySQL Quick Admin <= 1.5.5 (COOKIE) Local File Inclusion Vulnerability POC posted on milworm

Greetings All,

I am trying to reproduce the issue, but php is reporting some error:
like fail to open lang/…/…/…/…/…/…/…/…/…/…/etc/passwd%00; path=//lang.php.

vulnerable code is:

include("lang/".$_SESSION['language']."/lang.php");

exploit is: …/…/…/…/…/…/…/…/…/…/etc/passwd%00; path=/ as the value of vulnerable paramter.

exploit link is:http://milw0rm.com/exploits/6641

After observing this error i thought there must some issue with the application, so created a vulnerable php program whose
details are:

<?php

include("lang/".$_GET[filename]."/lang.php");

?>

Then i send a GET a request:

GET /vulnerable php?filename=lang/…/…/…/…/…/…/…/…/…/…/etc/passwd%00; path=/

still, i am observing same error.

This is happening because inside include function, there is an additon of /lang.php after the vulnerable parameter value
in both case.

I am not able to understand how the author manage to view the contents of /etc/passwd by this method.

please help me out.

Thanks in advance.