Virtualization is the creation of components, such as hardware platform, operating system, storage, processing power, memory, or network resource, in virtual environments. The applications of virtualization are spreading rapidly and the critical systems are working on virtualization infrastructures. However; the effects of security vulnerabilities which may occur can also be high. In this study, security risks that may arise in virtualization systems, ways to avoid risks, and security configuration of a sample virtualization system have been examined. It is aimed to create security awareness to users and administrators of virtualization systems, to show how the steps of risk avoidance which can be implemented by examining a sample system.