The paper presents the vulnerabilities of cloudstorage and various possible attacks exploiting thesevulnerabilities that relate to cloud security, which is one of thechallenging features of cloud computing. The attacks areclassified into three broad categories of which the socialnetworking based attacks are the recent attacks which areevolving out of existing technologies such as P2P file sharing.The study is extended to available defence mechanisms andcurrent research areas of cloud storage. Based on the study,simple cloud storage is implemented and the major aspectssuch as login mechanism, encryption techniques and keymanagement techniques are evaluated against the presentedattacks. The study proves that the cloud storage consumers arestill dependent on the trust and contracts agreed with theservice provider and there is no hard way of proven defensemechanisms against the attacks. Further down, the emergingtechnologies could possibly break down all key basedencryption mechanisms
