Expose objects (and even controls) as public properties (receive only controls) on the page Master. Then on each page aspxyou want to access these objects, add the following declaration at the top:
<%@ MasterType VirtualPath="~/MyMasterPage.master" %>
As @Kristof points out, just access your properties, e.g. Master.PropertyName
, , Session ( , , DB ). Page, . , Master, Page usercontrol, ( CurrentUser) .