  Cloud storage provides the simpler way to share the files privately and
publicly. A good Cloud Storage Provider (SCP) is not only measured by the
access speed or file size that can be shared to others, but also regarding the
security issues in file sharing itself. In this paper, we analyze the security
of file sharing in 3 Chinese CSPs, which are: Baidu, Weiyun and Kanbox. Those
CSPs have their own vulnerabilities that successfully revealed. We also provide
some suggestions to countermeasure the weaknesses so that they can maintain the
quality while improving the security.
