Veracode Static Analysis report flaw with CWE 918 when it detect data from outside of the application. Here is my code spinet

protected virtual void RetrieveFile(string filePath) {

string downloadURL = ConfigurationManager.AppSettings["FileDownloadURL"];

HttpWebResponse response = null;

System.IO.Stream dataStream = null;

try {

System.Net.WebRequest request = System.Net.WebRequest.Create(downloadURL + "?FilePath=" + Server.UrlEncode(filePath));

response = (HttpWebResponse)request.GetResponse();

dataStream = response.GetResponseStream();

Response.ClearHeaders();

Response.ClearContent();

Response.Flush();

Response.End();

}

catch (System.Threading.ThreadAbortException ex) { }

catch (Exception ex) {

      WSApplication.Application.Report(CommonMessages.ErrorWhileDownload, ex.ToString(), "RetrieveFile");

throw ex;

}

finally {

if (dataStream != null)

dataStream.Close();

if (response != null)

response.Close();

}

}