The remote host is vulnerable to a local 'privilege escalation' flaw.
According to its banner, the version of the Samba server installed on the remote host is affected by a flaw where a local attacker can gain group-0 access. In order for the exploit to work, the local system must be configured to use Microsoft Active Directory and return a NULL value for the group ID. Successful exploitation would result in the local attacker gaining elevated access on the local machine.
Upgrade to version 3.0.26 or higher.