Access Subsite list from root site using sharepoint hosted app

See more:

Office

SharePoint2013

I've a SharePoint Hosted App and its deployed to Root site. Using that App, I need to read items of specific list from all sub sites of that root site. My current Code:

 SP.SOD.executeFunc("sp.js", 'SP.ClientContext', function () {
    var hostsuburl = "Subsite URL goes here";
    var context = new SP.ClientContext(hostsuburl);
    var oList = context.get_web().get_lists().getByTitle("ResourceDetails");
    var camlQuery = new SP.CamlQuery();
    camlQuery.set_viewXml("<View><Query><Where><Eq><FieldRef Name='monthnumber'/><Value Type='Text'>" + CurrentMonth + "</Value></Eq></Where></Query></View>");
    this.collListItem = oList.getItems(camlQuery);
    context.load(collListItem, 'Include(ActualHours,AvailableHours,CostPerHour)');
    context.executeQueryAsync(function onQuerySucceeded(sender, args) {
    alert('Inside OnQuery succeeded');
    }
 , function onQueryFailed(sender, args) {
      alert('Failed to get lists. Error:n1' + args.get_message());
  });
});

When I deploy code, I'm getting into onQueryFailed function, and getting error as "Unexpected response data from server error". I've checked the CAML Query, It has no error. How can I get it done? Any help would be appreciated.
Thanks,
Arun