Unitrends Enterprise Backup bpserverd Privilege Escalation

It was discovered that the Unitrends bpserverd proprietary protocol, as exposed via xinetd,
has an issue in which its authentication can be bypassed. A remote attacker could use this
issue to execute arbitrary commands with root privilege on the target system.
This is very similar to exploits/linux/misc/ueb9_bpserverd however it runs against the
localhost by dropping a python script on the local file system. Unitrends stopped
bpserverd from listening remotely on version 10.