Macro Expert 4.0 - Multiple Privilege Escalation

2016-09-26 00:05:46

# Exploit Title: Macro Expert 4.0 Multiple Elevation of Privilege
# Date: 26/09/2016
# Exploit Author: Tulpa
# Contact: [email protected]
# Author website: www.tulpa-security.com
# Vendor Homepage: http://www.macro-expert.com/
# Software Link: http://www.macro-expert.com/download.htm
# Version: Software Version 4.0
# Tested on: Windows 7 x86
# Shout-out to carbonated and ozzie_offsec

1. Description:
Macro Expert installs as a service with an unquoted service path running with SYSTEM

privileges. This could potentially allow an authorized but non-privileged local
user to execute arbitrary code with elevated privileges on the system. Additionally the

default installation path suffers from weak folder permission which an unauthorized user

in the BUILTIN\Users group could take advantage of.

2. Proof

C:\Program Files\GrassSoft>sc qc "Macro Expert"
[SC] QueryServiceConfig SUCCESS

SERVICE_NAME: Macro Expert
TYPE : 10 WIN32_OWN_PROCESS
START_TYPE : 2 AUTO_START
ERROR_CONTROL : 1 NORMAL
BINARY_PATH_NAME : c:\program files\grasssoft\macro expert\MacroService.exe
LOAD_ORDER_GROUP :
TAG : 0
DISPLAY_NAME : Macro Expert
DEPENDENCIES :
SERVICE_START_NAME : LocalSystem

C:\Program Files\GrassSoft>cacls "Macro Expert"
C:\Program Files\GrassSoft\Macro Expert BUILTIN\Users:(OI)(CI)C
NT SERVICE\TrustedInstaller:(ID)F
NT SERVICE\TrustedInstaller:(CI)(IO)(ID)F
NT AUTHORITY\SYSTEM:(ID)F
NT AUTHORITY\SYSTEM:(OI)(CI)(IO)(ID)F
BUILTIN\Administrators:(ID)F
BUILTIN\Administrators:(OI)(CI)(IO)(ID)F
BUILTIN\Users:(ID)R
BUILTIN\Users:(OI)(CI)(IO)(ID)(special access:)
GENERIC_READ

GENERIC_EXECUTE

CREATOR OWNER:(OI)(CI)(IO)(ID)F


3. Exploit:

A successful attempt would require the local user to be able to insert their
code in the system root path undetected by the OS or other security applications
where it could potentially be executed during application startup or reboot.
If successful, the local user's code would execute with the elevated privileges
of the application.

Fixes

No fixes

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