use admin
db.createUser(
  {
    user: "myUserAdmin",
    pwd: "abc123",
    roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]
  }
)

2016-10-26T08:40:09.218+0300 I NETWORK  [conn45] end connection 127.0.0.1:59014 (0 connections now open)
2016-10-26T08:40:09.718+0300 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:59015 #46 (1 connection now open)
2016-10-26T08:40:09.721+0300 I NETWORK  [conn46] end connection 127.0.0.1:59015 (0 connections now open)
2016-10-26T08:40:10.221+0300 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:59016 #47 (1 connection now open)
2016-10-26T08:40:10.224+0300 I NETWORK  [conn47] end connection 127.0.0.1:59016 (0 connections now open)
2016-10-26T08:40:10.725+0300 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:59017 #48 (1 connection now open)
2016-10-26T08:40:10.728+0300 I NETWORK  [conn48] end connection 127.0.0.1:59017 (0 connections now open)