2.6 Perform testing procedures A1.1 through A1.4 detailed in Appendix A1: Additional PCI DSS Requirements for Shared Hosting Providers for PCI DSS assessments of shared hosting providers, to verify that shared hosting providers protect their entities’ (merchants and service providers) hosted environment and data.
This is intended for hosting providers that provide shared hosting environments for multiple clients on the same server. When all data is on the same server and under control of a single environment, often the settings on these shared servers are not manageable by individual clients. This allows clients to add insecure functions and scripts that impact the security of all other client environments; and thereby make it easy for a malicious individual to compromise one client’s data and thereby gain access to all other clients’ data. See Appendix A1 for details of requirements.