Titan FTP Server Version 2019 Build 3505 - Directory Traversal / Local File Inclusion

# Exploit Title: Titan FTP Server Version 2019 Build 3505 Directory Traversal/Local File Inclusion
# Google Dork: N/A
# Date: 3/26/2019
# Exploit Author: Kevin Randall
# Vendor Homepage: https://titanftp.com/
# Software Link: https://titanftp.com/download
# Version: Firmware: Titan FTP Server Version 2019 Build 3505
# Tested on: Windows 7 32 Bit
# CVE : CVE-2019-10009
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Discovered By: Kevin Randall on 3/23/2019
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A Directory Traversal issue was discovered in the Web GUI in Titan FTP Server 2019 Build 3505.
When an authenticated user attempts to preview an uploaded file (through PreviewHandler.ashx) by using a \..\..\ technique, arbitrary files can
be loaded in the server response outside the root directory.
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Tools used:

Parrot OS

Windows 7 32 Bit

BurpSuite

Browser
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Vulnerability has been fixed in the following build:
Build: Titan FTP Server 2019 Build 3515
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Proof of Concept (PoC):

Step 1: Authenticate through Titan FTP Web GUI

Step 2: Upload file and attempt to view it

Step 3: Intercept requests with BurpSuite when attempting to view uploaded file

Step 4: Modify "path=" and "filename=" parameters in the following GET request:
Ex: View contents of README.txt file in Python27 directory:
Note: You can access other files in directories such as System32, Desktop etc.
Payload:
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GET /PreviewHandler.ashx?path=\..\..\..\..\Python27\README.txt&filename=README.txt
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Step 5: If path is set-up correctly and if file exists, you will receive a 200 OK back from the server.

Step 6: View the file through the file preview in the FTP server.
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Timeline:

Date Discovered: 3/23/2019
Date Disclosed to Vendor: 3/23/2019
CVE Obtained: 3/24/2019
Vendor Created Patched Version Titan FTP Version 2019 Build 3515: 3/25/2019
Vendor Created Entry in Jira System for issue (SVR-499): 3/25/2019
Date Disclosed: 3/26/2019

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