Cloud computing offers a new way to deliver services while significantly changing the cost structure underlying those services. This new technical and pricing opportunities change in the way the business operate. It combines the features of traditional computing technology like grid, parallel and distributed computing and so on. The aim of cloud computing is to provide a high performance computing system to the customer with the low cost without relying on their own infrastructure. The cloud offers the various levels of services like Software-as-a-Service (SaaS), Platform-as-a-Service (PaaS) & Infrastructure-as-a- Service (IaaS) to the customers over the internet. Since all the services are offered over the internet, there is a great deal of uncertainty about security and privacy at various levels are arises. This extensive survey article aims to address security and privacy issues threatening the cloud computing adoption at the end user at the various levels (network, host, and application and data levels). © 2005 - 2013 JATIT & LLS. All rights reserved.