Government entities, handling confidential information in legal services and projects, are frequent targets of cyberattacks. These institutions are responsible for ensuring that their web portals use secure transmission protocols when exchanging data with users. The central issue of this study is the deficiency in information transmission protocols in e-government portals of municipalities, which impacts the implementation of security controls, vulnerability assessments, and the costs and consequences of security breaches. Therefore, the systematic review aims to synthesize and critically analyze existing studies that evaluate vulnerabilities and cyber risks in web portals. Our research began with a systematic literature search that identified 19 relevant documents. Based on this analysis, the study seeks to address key questions related to identifying the main threats, risks, and vulnerability scenarios to which municipalities are exposed. Additionally, it examines the various impacts that may arise for local governments due to the services provided through the use of HTTP (Hypertext Transfer Protocol) and HTTPS (Hypertext Transfer Protocol Secure) protocols on their websites, as well as the cybersecurity criteria and standards necessary to establish effective security controls.