Field programming gate array is a semiconductor device used for programming tasks in parallel with greater efficiency and performance that the general core processors present in our desktop. Larger tasks can be parallelized at a much faster rate. The need for more high-performance computing is increasing, especially in the field of cloud after the patches for effects like “Specter” and “Meltdown” have reasonably slowed down the processors in turn affecting the entire cloud, the need for FPGA accelerators have increased . But there are kinds of security attacks on which FPGA makes it vulnerable and harm clouds. In this paper, the various vulnerabilities of FPGAs try to analyze the kind of attacks on FPGA. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd 2021.