Your software at my service: Security analysis of saas single sign-on solutions in the cloud

Software-as-a-Service (SaaS) is typically defined as a rental model for using a complex software product, running on a centralized computing platform, using a thin client (most frequently a web browser). As such, it is one of the major categories of Cloud Com-puting, besides IaaS and PaaS. While there are many economic benefits in using SaaS, each company must nevertheless enforce control over its own data pro-cessed in the Cloud. One of the most important building blocks of such an enforcement scheme is Identity Management (IdM), whereat the industry standard for IdM is SAML, the Security As-sertion Markup Language. In this paper, we study the security of the SAML implementa-tions of 22 SaaS Cloud Providers (SaaS-CPs) and show that 90% of them can be broken, resulting in company data exposure to at-tackers on the Internet. The detected vulnerabilities are exploited by a wide variety of attack techniques, ranging from classical web attacks to problems specific to XML processing