InstantHMI - EoP: User to ADMIN

vendor:

InstantHMI

by:

sh4d0wman

7.5

CVSS

HIGH

Elevation of Privilege

276

CWE

Product Name: InstantHMI

Affected Version From: 6.1

Affected Version To: 6.1

Patch Exists: NO

Related CWE:

CPE:

Metasploit:

Other Scripts:

Platforms Tested: Windows 7 x86

2016

InstantHMI – EoP: User to ADMIN

During a standard installation of InstantHMI, the installer automatically creates a folder named "IHMI-6" in the root drive with incorrect default permissions. AUTHENTICATED USERS are given WRITE permission, allowing them to replace binaries or plant malicious DLLs to obtain elevated, administrative level privileges.

Mitigation:

Install the software under "c:\program files" or "C:\Program Files (x86)" and set appropriate permissions on the application folder.

Source

Exploit-DB raw data:

Title: InstantHMI - EoP: User to ADMIN
CWE Class: CWE-276: Incorrect Default Permissions
Date: 01/06/2016
Vendor: Software Horizons
Product: InstantHMI
Version: 6.1 
Download link: http://www.instanthmi.com/ihmisoftware.htm
Tested on: Windows 7 x86, fully patched
Release mode: no bugbounty program, public release

Installer Name: IHMI61-PCInstall-Unicode.exe
MD5: ee3ca3181c51387d89de19e89aea0b31
SHA1: c3f1929093a3bc28f4f8fdd9cb38b1455d7f0d6f

- 1. Introduction: -
During a standard installation (default option) the installer 
automatically creates a folder named "IHMI-6" in the root drive. 
No other location can be specified during standard installation.

As this folder receives default permissions AUTHENTICATED USERS 
are given the WRITE permission. 

Because of this they can replace binaries or plant malicious 
DLLs to obtain elevated, administrative level, privileges.

- 2. Technical Details/PoC: -
A. Obtain and execute the installer. 

B. Observe there is no prompt for the installation location.

C. Review permissions under the Explorer Security tab or run icacls.exe

Example:

IHMI-6 BUILTIN\Administrators:(I)(F)
       BUILTIN\Administrators:(I)(OI)(CI)(IO)(F)
       NT AUTHORITY\SYSTEM:(I)(F)
       NT AUTHORITY\SYSTEM:(I)(OI)(CI)(IO)(F)
       BUILTIN\Users:(I)(OI)(CI)(RX)
       NT AUTHORITY\Authenticated Users:(I)(M)
       NT AUTHORITY\Authenticated Users:(I)(OI)(CI)(IO)(M)

Successfully processed 1 files; Failed processing 0 files

D. Change the main executable: InstantHMI.exe with a malicious copy. 

E. Once executed by an administrator our code will run 
under administrator level privileges.

- 3. Mitigation: -
A. Install under "c:\program files" or "C:\Program Files (x86)"

B. set appropriate permissions on the application folder.

- 4. Author: -
sh4d0wman