The remote Samba server is affected by a buffer overflow vulnerability.
According to its banner, the version of Samba 3.x running on the remote host is earlier than 3.5.5. The 'sid_parse()' and related 'dom_sid_parse()' functions in such versions fail to correctly check their input lengths when reading a binary representation of a Windows SID (Security ID). An attacker who is able to get a connection to a file share, either authenticated or via a guest connection, can leverage this issue to launch a stack buffer overflow attack against the affected smbd service and possibly execute arbitrary code.
Either apply one of the patches referenced in the project's advisory or upgrade to 3.5.5 / 3.4.9 / 3.3.14 or later.