response.sendRedirect("http://prasad-pc:8080/xxxxbankapp/index.jsp");//Redirecting To Another Application Which Is Running On Same Server....From xxxxbankapp index.jsp, When Click On Submit It Invokes ValidateUserDetails Servlet... }
The session scope cannot surpass the application scope. So there is no scope shared by multiple applications, even on same server.
You can add the field in the request and submit the request to the second application, send it as hidden field, query parameter,etc.
Only making use of session does not make the data transfer "secure". It should be using SSL, or field encryption for sensitive fields.