Your initial attempt to get hashes from $/$etc$/$password on the Linux system did not work because the shadow password file is in use and the shellshock exploit did not get you root access. However, the system may be vulnerable to other exploits that gain root access. Research the exploit$/$unix$/$ftp$/$vsftpd$\_234\_$backdoor module in Metasploit and determine how to use it to gain access to the target machine. Use the exploit to get a root shell and view the contents of $/$etc$/$shadow$.$