Samba 3.x and 4.x before 4.2.11, 4.3.x before 4.3.8, and 4.4.x before 4.4.2 does not require SMB signing within a DCERPC session over ncacn_np, which allows man-in-the-middle attackers to spoof SMB clients by modifying the client-server data stream.
Exploitability
AV:NAC:HPR:NUI:NScope
S:UImpact
C:NI:HA:N5.9/CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N