Cloud computing is one of the fastest growing and popular technology in the field of computing. As the concept of cloud computing was introduced in 2006. Since then large number of IT industries join the queue to develop many cloud services and put sensitive information over cloud. In fact cloud computing is no doubt the great innovation in the field of computing but at the same time also poses many challenges. Since a large number of organizations migrate their business to cloud and hence it appears as an attractive target for the malicious attack. The purpose of the paper is to review the available literature for security concerns and highlight a relationship between vulnerabilities, attacks and threats in SaaS model. A mapping is being presented to highlight the impact of vulnerabilities and attacks.

The world of computing rapidly changed from mainframe to client server architecture and towards the new world of cloud computing. This new generation of computing has tremendous advantages over traditional offerings. Irrespective of all, security is one of the biggest hurdles which hold the migration of business towards cloud. Main reason is client unawareness about the security counters and their roles. Security control can be normally implemented around three levels such as vulnerability, attack and threat. It is better to identify and pre analyse the concerns at earliest level. The purpose of research is to visualize the vulnerability management process in the modular form and make a transparent responsibility picture for each actor. In the end of the research a new term threshold limit was highlighted in vulnerability life cycle.