Multiple stack-based buffer overflows in the NTR ActiveX control before 2.0.4.8 allow remote attackers to execute arbitrary code via (1) a long bstrUrl parameter to the StartModule method, (2) a long bstrParams parameter to the Check method, a long bstrUrl parameter to the (3) Download or (4) DownloadModule method during construction of a .ntr pathname, or a long bstrUrl parameter to the (5) Download or (6) DownloadModule method during construction of a URL.