php imap_open Remote Code Execution

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.