This module exploits a vulnerability found in Narcissus image configuration function. This is due to the backend.php file not handling the $release parameter properly, and then passes it on to the configure_image() function. In this function, the $release parameter can be used to inject system commands for passthru (a PHP function that's meant to be used to run a bash script by the vulnerable application), which allows remote code execution under the context of the web server.
To display the available options, load the module within the Metasploit console and run the commands 'show options' or 'show advanced':
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