Human Machine Interfaces (HMIs) are the subsets of the Supervisory Control and Data Acquisition (SCADA) systems. HMIs are control panels that provide interfaces for humans to interact with machines and to manage operations of various types of SCADA systems. HMIs have direct access to SCADA databases including critical software programs. The majority of SCADA systems have web-based HMIs that allow the humans to control the SCADA operations remotely through Internet. This talk unveils various flavors of undisclosed vulnerabilities in web-based SCADA HMIs including but not limited to remote or local file inclusions, insecure authentication through clients, weak password hashing mechanisms, firmware discrepancies, hardcoded credentials, insecure web-services, weak cryptographic design, cross-site request forgery, and many others. This talk digs deeper into the design models of various SCADA systems to highlight security deficiencies in the existing SCADA HMI deployments. The research is driven with a motivation to secure SCADA devices and to build more intelligent solutions by hunting vulnerabilities in SCADA HMIs. The vulnerabilities presented in this talk are completely undisclosed and will be revealed for the first time with live demonstrations.