Month: March 2015

LFi Freak – An Automated File Inclusion Exploiter

I am sure you know about exploiting file inclusion vulnerabilities. In file inclusion situations in common we can read files arbitrarily in the system or remotely depending on the permissions. In PHP environments commonly we poison the log files or inject malicious PHP into the user agent header and load the “/proc/self/environ” file. However when we encounter file inclusion situations in PHP environments we can use the in-built PHP wrappers to make our exploitations much easier or perhaps bypass existing filters.

There are lot of LFI exploitation tools available but I’ve written this tool mainly focusing on the usage of “php://input”, “php://filter” and “data://” methods.  Even though the title explicitly conveys “LFI Freak” this can be used for RFI vulnerabilities as well. This tool is written in Python 2.7 and I have included binaries for both Windows and Linux systems. If you are running from the source or want to modify this, you need the BeautifulSoup library.

Here is a small walkthrough of the features of the tool.

To test for local or remote file inclusions you can use the option one “Automated testing”. I am using DVWA in here. To test this tool create a small vulnerable file.
[code language=”php”]
<?php
echo "File included: ".$_REQUEST["page"]."<br>";
$file = $_REQUEST["page"];
include $file;
?>
[/code]
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Dynamic Function Injection in PHP

In PHP we can pass arguments to a function dynamically during runtime. For example have look at this example.

View post on imgur.com

I have used call_user_func_array() to pass the arguments to the function. The syntax would be:
[code language=”php”]
call_user_func_array(function, param_arr)
[/code]
Since I have used $_GET we can pass the function and its arguments during runtime.

http://localhost/?func=user&args[]=Osanda&args[]=secret&args[]=abc@abc.com

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Running Shellcode in your Raspberry Pi

I was interested in learning ARM assembly language for developing small applications for microcontrollers. I wrote this small piece of shellcode which will write “127.0.0.1 google.lk” inside the /etc/hosts file in a Linux system. I used my Raspberry Pi model B+ for this 🙂
Image result for raspberry pi b+
We will be needing the following syscalls.

[code language=”c”]
#define __NR_exit (__NR_SYSCALL_BASE+ 1)
#define __NR_write (__NR_SYSCALL_BASE+ 4)
#define __NR_open (__NR_SYSCALL_BASE+ 5)
#define __NR_close (__NR_SYSCALL_BASE+ 6)
[/code]

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