1. OVERVIEW

KingSoft Office 2010 Suite application is vulnerable to Insecure DLL
Hijacking Vulnerability. Similar terms that describe this
vulnerability have been come up with Remote Binary Planting, and
Insecure DLL Loading/Injection/Hijacking/Preloading.


2. PRODUCT DESCRIPTION

Kingsoft Office offers robust set of features that you needed to
create professional documents. It contains three essential office
applications: Kingsoft Writer, Kingsoft Presentation, and Kingsoft
Spreadsheets with familiarity of interface and ease-to-use functions.
No re-learning process is required. With its strong compatibility with
variety of file formats, Kingsoft Office 2010 is the best alternative
to Microsoft Office.


3. VULNERABILITY DESCRIPTION

Kingsoft Office Suite applications pass an insufficiently qualified
path in loading their external libraries
 when a user opens its associated file with extensions.

 KingSoft Office Writer
  - affected dll: plgpf.dll
  - affected extention: doc, rtf

 KingSoft Office Presentation
  - affected dll: plgpf.dll
  - affected extention: ppt
  
 KingSoft Office Spreadsheets
  - affected dll: plgpf.dll
  - affected extention: xls
  

4. VERSIONS AFFECTED

2008 and probably lower versions


5. PROOF-OF-CONCEPT/EXPLOIT

http://core.yehg.net/lab/pr0js/advisories/dll_hijacking/kingsoft-office-2010/poc/movie/kingsoft-office-2010_dll-hijacking.mp4
http://core.yehg.net/lab/pr0js/advisories/dll_hijacking/kingsoft-office-2010/poc/kingsoft-office-2010_dll-hijacking-poc.zip

Tested Platform: Windows XP Service Pack 3 (Fresh Windows)


6. IMPACT

Attackers can trigger a successful exploit against a victim user in a
number of ways such as placing a malicious external
library file made as hidden attribute and a seemingly interesting file
in network shares, usb drives, file sharing networks,
social networks, ..etc  


7. SOLUTION

Fixed version from the vendor has not been released yet.
However, it is suggested that the following workarounds be deployed by
users to protect increasing mass exploitation of this
vulnerability class:
- Disable loading of libraries from WebDAV and remote network shares
- Disable the WebClient service
Please see workaround solution links in References section.


8. VENDOR

Kingsoft Corp.
http://www.kingsoftresearch.com/kso.php


9. CREDIT

This vulnerability was discovered by Aung Khant, http://yehg.net, YGN
Ethical Hacker Group, Myanmar.


10. DISCLOSURE TIME-LINE

09-11-2010: notified vendor
09-13-2010: vulnerability disclosed


11. REFERENCES

Original Advisory URL:
http://core.yehg.net/lab/pr0js/advisories/dll_hijacking/[kingsoft_office]_2010_insecure_dll_hijacking
KingSoft Wiki: https://secure.wikimedia.org/wikipedia/en/wiki/Kingsoft_Office
Workaround Solution: http://support.microsoft.com/kb/2264107
Workaround Solution:
https://www.microsoft.com/technet/security/advisory/2269637.mspx#EGF
Developer Solution:
http://msdn.microsoft.com/en-us/library/ff919712%28v=VS.85%29.aspx
Unofficial DLL Hijacking List:
http://www.corelan.be:8800/index.php/2010/08/25/dll-hijacking-kb-2269637-the-unofficial-list/
Testing for DLL Hijacking:
http://core.yehg.net/lab/pr0js/view.php/when_testing_for_dll_hijacking.txt

#yehg [09-13-2010]