Two years ago, communications in the telecommunication industry have sparked significant concern regarding the ease with which Open RAN could potentially be hacked [9][10], prompting a deeper exploration of its security implications for the mobile telecommunications sector and related fields. Open RAN, heralded as a transformative force in telecom infrastructure through its innovative standards and concepts, has not only captured the industry's attention for its ability to shift paradigms but also for the security challenges it may introduce, particularly in areas where integrity, confidentiality, and availability are paramount. Security experts have drawn parallels between the vulnerabilities in Open RAN and those found in cloud infrastructures relying on Docker and Kubernetes, underscoring the importance of scrutinizing OpenRAN's unique risk profile [1]. The discourse is further enriched by analyses that identify new interfaces Open RAN will introduce for interconnecting various network functions [2], highlighting potential attack vectors. Despite the wealth of small existing literature, the abstract nature of these risks has led to the initiation of this article, aiming to elucidate practical attack strategies against current Open RAN implementations and identify emerging threats. Employing the state-of-the-art open-source O-RAN [13] stack as a case study, this series seeks to shed light on the evolving security requirements of Open RAN. An examination of existing products that are "ready for commercial deployment" and compliant with O-RAN standards reveals a complex security landscape, necessitating a comprehensive analysis of risks under typical deployment scenarios [3]. This article sets the stage by introducing Open RAN, its predecessors, and its overarching architecture, followed by a detailed examination of the communication interfaces that could serve as attack vectors, and practical attack we can perform using O-RAN stack.