CVE-2017-12150

It was found that samba did not enforce “SMB signing” when certain configuration options were enabled. A remote attacker could launch a man-in-the-middle attack and retrieve information in plain-text.

Mitigation

The missing implied signing for 'smb2mount -e', 'smbcacls -e' and 'smbcquotas -e' can be enforced by explicitly using '--signing=required' on the commandline or "client signing = required" in smb.conf.