Null Pointer Dereference vulnerability exists in TRENDnet TEW-755AP 1.11B03 TEW-755AP2KAC 1.11B03 TEW-821DAP2KAC 1.11B03 and TEW-825DAP 1.11B03 by sending the POST request to apply_cgi via a do_graph_auth action without a session_id key.