Critical infrastructure such as power plants, oil refineries, and sewage are at the core of modern society. Supervisory Control and Data Acquisition (SCADA) systems were designed to allow human operators supervise, maintain, and control critical infrastructure. Recent years has seen an increase in connectivity of SCADA systems to the Internet. While this connectivity provides an increased level of convenience, it also increases their susceptibility to cyber-Attacks. Given the potentially severe ramifications of exploiting SCADA systems, the purpose of this study is to utilize passive and active vulnerability assessment techniques to identify the vulnerabilities of Internet enabled SCADA systems. Specifically, we collect a large testbed of SCADA devices from Shodan, a search engine for the IoT, and assess their vulnerabilities with Nessus and against the National Vulnerability Database (NVD). Results of this study indicate that many SCADA systems from major vendors such as Rockwell Automation and Siemens are vulnerable to default credential, man-in-The-middle, and SSH exploit attacks.