Да, но вопрос в том, с каким именем пользователя будет иметь дело
Samba. В случае с security = SHARE действуют достаточно сложные правила
для определения этого имени:

A list of possible UNIX usernames to match with the
              given client password is constructed using the fol-
              lowing methods :

              o If the guest only parameter is set, then all  the
                other  stages  are  missed  and  only  the  guest
                account username is checked.

              o Is a username is sent with the  share  connection
                request,  then this username (after mapping - see
                username map), is added as a potential  username.

              o If  the  client did a previous logon request (the
                SessionSetup SMB call) then the username sent  in
                this SMB will be added as a potential username.

              o The  name  of the service the client requested is
                added as a potential username.

              o The NetBIOS name of the client is  added  to  the
                list as a potential username.

              o Any  users  on the  user list are added as poten-
                tial usernames.