Access denied while making get call to Inflowblox from Sharepoint

I'm trying to make one get request to a REST endpoint from Sharepoint to Infloblox but I'm always getting an access denied error, even though we are passing the basic Authorizations.

XMLHttpRequest: Network Error 0x80070005, Access is denied.

var settings = {
  "async": true,
  "crossDomain": true,
  "url": "https://x.x.x.x/wapi/v1.2.1/network?_return_fields%2B=extattrs&*VLAN%3A=xxxx&*Site%3A=xxx&_return_as_object=1",
  "method": "GET",
  "headers": {
    "Authorization": "Basic some_authentication_token",
    "Cache-Control": "no-cache",
    "Postman-Token": "postmantoken"
  }
}

$.ajax(settings).done(function (response) {
  alert(response);
});