USN-4559-1: Samba update

Tom Tervoort discovered that the Netlogon protocol implemented by Samba incorrectly handled the authentication scheme. A remote attacker could use this issue to forge an authentication token and steal the credentials of the domain admin. While a previous security update fixed the issue by changing the "server schannel" setting to default to "yes", instead of "auto", which forced a secure netlogon channel, this update provides additional improvements. For compatibility reasons with older devices, Samba now allows specifying an insecure netlogon...