The imap_open function within php, if called without the /norsh flag, will attempt to preauthenticate an IMAP session. On Debian based systems, including Ubuntu, rsh is mapped to the ssh binary. Ssh's ProxyCommand option can be passed from imap_open to execute arbitrary commands. While many custom applications may use imap_open, this exploit works against the following applications: e107 v2, prestashop, SuiteCRM, as well as Custom, which simply prints the exploit strings for use. Prestashop exploitation requires the admin URI, and administrator credentials. suiteCRM/e107 require administrator credentials. Fixed in php 5.6.39.
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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