Voice authentication systems are a comfortable way of protection since users do not need to remember passwords or carry identification cards. As a unique identifier for all individuals, voice is a practical tool to authenticate people into security services. In this paper, recent single-modal and multimodal voice authentication studies are reviewed with an explanation of underlying feature extraction and classification methods. This paper also discusses security attacks on voice authentication systems, including random attacks, mimicry attacks, replay attacks, voice synthesizing attacks, counterfeit attacks, and hidden voice command attacks.