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© 2010-2011 Cisco, Coalfire, HyTrust, Savvis, Trend Micro, VMware. All rights reserved.

P C I-C ompliant C loud R eferenc e Arc hitec ture

Cisco, VMware, HyTrust, Trend Micro, Savvis and Coalfire have collaborated to construct a cloud reference architecture that addresses some of the unique challenges of the Payment Card Industry (PCI) Data Security Standard (DSS). Innovative technologies from Cisco, VMware, Trend Micro and HyTrust are used to implement the cloud architecture with a number of additional security controls to meet the intent of PCI DSS. The reference architecture was implemented in the Savvis lab and the team collaborated with Coalfire, which provided guidance as a PCI Qualified Security Assessor (QSA).

August 16th, 2011

Introduction The Payment Card Industry (PCI) Data Security Standard (DSS) defines a set of requirements to protect cardholder data, and the environments in which cardholder data is stored, processed, or transmitted. This comprehensive set of requirements cover information technology management, policy and procedures, network architecture, software design, and other defensive security measures. Additionally, these requirements apply to all “system components,” which are defined as any network component, server, or application that is included in or connected to the Cardholder Data Environment (CDE), including any virtualization components such as virtual machines, virtual switches/routers, virtual appliances, virtual applications/desktops, and hypervisors. The challenge with the Data Security Standard is that technology is constantly evolving and often times security and audit capabilities are built in after the initial foundation of technology has been established.

In particular, virtualized and cloud environments have some unique challenges, which include segmentation, storage of cardholder data, access control, encryption, logging and alerting across all management activities, and use of the base platform layer (i.e. the hypervisor). The PCI Security Standards Council published guidance in June 2011 for virtualization. It empowers PCI Qualified Security Assessors (QSAs), merchants, service providers, processors and vendors to work collaboratively to create a compliance approach to specific emerging technologies through four simple principals:

a. If virtualization technologies are used in a CDE, PCI DSS requirements apply to those virtualization technologies.

b. Virtualization technology introduces new risks that may not be relevant to other technologies, and that must be assessed when adopting virtualization in CDEs.

c. Implementations of virtual technologies can vary greatly, and entities will need to perform a thorough discovery to identify and document the unique characteristics of their particular virtualized implementation, including all interactions with payment transaction processes and payment card data.

d. There is no one-size-fits-all method or solution to configure virtualized environments to meet PCI DSS requirements. Specific controls and procedures will vary for each environment, according to how virtualization is used and implemented.

The PCI DSS is a vendor agnostic standard which applies to a variety of technologies and solutions. This document intends to provide detailed guidance, specific to the vendors and service provider mentioned, for a basic framework and practical implementation for building a PCI-compliant cloud.

The terms “virtualization” and “cloud computing” do not exist in the previous version of PCI DSS (version 1.2.1). It lacked specific advice about whether CDE system components need to be physical. This is not surprising, as it was developed before virtualization technologies gained wide spread adoption. In the current PCI DSS (version 2.0), released October 2010, “System Components” include virtualization technology (hypervisors) and virtual system components such as VMs, virtual switches, virtual routers and networks, virtual appliances, virtual applications and desktops.


Herein lies the first challenge: If an in-scope CDE system component is virtualized, can it be adequately protected to meet all PCI DSS requirements? What other systems now fall within the scope of the PCI CDE?

PCI DSS controls typically form the foundation for enterprise (both commercial and public sector) internal security practices. To reduce the burden and cost of an audit, the PCI DSS suggests that network segmentation be used to isolate the CDE (i.e. protect the CDE from other networks and systems) thus reducing the scope of what is being assessed for compliance. The primary reason for virtualization adoption is cost reduction of both capital and operating expenditures through physical-server consolidation.

Herein lies the second challenge: How can virtualized system components (servers, network components, security components, management and monitoring components, and such) within a CDE be co-mingled with virtualized system components used for non-CDE functions? Can CDE virtual system-components reside on the same physical system as non-CDE virtual system-components, and still achieve PCI DSS compliance?

After enterprises have gained an understanding of, and confidence in, virtualized infrastructures, they will take the next step in the virtualization journey and implement a private cloud model where everything (compute, memory, network, storage) is abstracted and becomes one large shared resource pool. The adoption of a private cloud model truly eliminates the concepts of physical segmentation and isolation, and introduces a world of infrastructure elasticity and operational flexibility. How does the PCI DSS view this dynamic pooled computing model? Workloads are governed by the PCI DSS. The environments that house these workloads are governed by the PCI DSS. The people that access and manage these environments are governed by the PCI DSS. The processes used are governed by the PCI DSS. What about dynamic scaling: how should that be controlled and configured?

Herein lies the third challenge: How can adopters of emerging technology satisfy the intent of the PCI DSS, and adequately protect cardholder data without specific, detailed guidance?

This document presents a reference architecture and additional controls needed to address the three cloud challenges mentioned above to achieve PCI compliance.

Architecture Use Case: E-Commerce Merchant An example use case of an e-commerce merchant is presented in this reference architecture. This reference architecture can be equally applied to other similar use cases.

• The e-commerce merchant uses a cloud to host its e-commerce website. It receives payment via card-not-present transactions (e-commerce). Assume, for the purposes of this reference architecture, that the cloud infrastructure is provided by Savvis solely to this e-commerce merchant and resides in facilities owned and operated by Savvis. That is, the cloud (a virtual private datacenter) is not shared with any other merchant, and all virtual compute resources are dedicated to the merchant. However, physical compute, network and storage components are shared across many merchants.

• The cloud infrastructure is co-managed by the e-commerce merchant and Savvis. In addition, to reduce costs, the merchant uses the same cloud infrastructure to: run a support forum; store its product catalog in a database; and operate the management, security and other infrastructure systems necessary for the application of these other systems. The merchant essentially needs to co-mingle CDE VMs with non-CDE VMs, sometimes referred to as a ‘mixed-mode’ environment.

• Different types and tiers of workloads are co-mingled on the same hypervisor. Payments are processed through a third-party payment processor managed and operated by the third-party in its own facility.

• The cloud environment provided by Savvis is validated as PCI-compliant, and the required 12.8 service provider verbiage is contained within the merchant’s contract. However, since there is co-management of the cloud environment by the merchant and cloud provider/Savvis, each entity has the ability to impact the security of the merchant’s cardholder data. Therefore the merchant must provide PCI validation of all system components that the merchant directly manages as well as a partial validation of system components that are co-managed. Validation requirements for co-managed environments are not


specifically addressed by the PCI DSS, and opinions are likely to vary regarding the extent to which “co-validation” is necessary, including documentation and keeping ongoing monitoring records.

Scope of Work and Approach Taken The reference architecture implemented in the Savvis lab is based on the Internet access point, the physical system components, the virtualization platforms, the virtualized infrastructure components, the VMs, the Storage Area Network (SAN), and physical storage (as shown in Figure 1 below). Figure 1 Cloud Provider Network Scope Diagram

A disaster recovery (DR) instance of the same functional reference architecture is housed in a geographically separated datacenter lab, and provides redundancy. The same administrators that manage the primary reference architecture also manage this instance. The DR instance is not addressed in this document. In this cloud environment a number of segmented networks are created to provide separation of access and a layered defense for each cloud. Both physical and virtual firewalls are used to implement physical and virtual network segmentation. All system components (virtual and physical) that are shared (such as load balancers, routers/switches, and firewalls) are considered in-scope for the CDE, and their configurations are reviewed. The assessor will use their understanding of the environment and payment process to select representative sample for testing.

The Cardholder Data Environment The cloud environment is co-managed by the e-commerce merchant and the cloud provider. The merchant is allowed to perform a limited set of administrative activities through the customer portal (for example, to start and stop a VM and to administer the application running within it), as shown in Figure 1. The customer/enterprise portal limits a customer’s visibility to only their environment, authenticates via 2-factor authentication mechanism per PCI DSS requirement 8.3, and authorizes each access, and has detailed monitoring for abuse. The provider is responsible for most of the management tasks and maintains separation-of-duties from a business and


technical perspective. Each logical business layer is separated through network segmentation and firewall(s), as shown in Figures 1 and 2. The cloud provider environment consists of individual Virtual Private Data Centers (VPDCs), which are a collection of network, security, storage and compute resources and processes that exist “in the cloud.” The resources and processes provided by the VPDCs were specifically designed to support multi-tenant deployment infrastructure in separate logical containers. Effectively, each VPDC is dedicated to a merchant, but the underlying infrastructure supports multi-tenancy. These VPDCs support multiple levels of service options including network service-level-agreements (SLAs), security SLAs, compute SLAs, quality of service (QoS), and backup. The cloud provider environment consists of the following elements (see Figures 1 and 2):

• Network access: Represents the configuration elements related to authentication and authorization zones (internet, DMZ, internet optimized, private, and private optimized).

• Perimeter security: Represents the configuration elements related to segmentation policies from the internet including web application firewall, perimeter firewall, data leakage prevention, threat management, messaging, and URL filtering policies.

• Redirection: Represents the configuration elements related to the site/data-center selection methods (virtual or dedicated).

• Network delivery: Represents the configuration elements related to server availability (basic or high availability).

• Compute Tiers: Represents the configuration elements associated with the server tiers, including: CPU, memory, resource management, application configuration, security hardening, and associations.

• SAN connected to tier-3 media (SATA drives): Represents the configuration elements related to data access, protection, and storage latency.

Data access: Block base storage using radial placement technology and automated RAID migration. All writes are on RAID 10 and then migrated to RAID 6.

Data protection: Uses failure consistent Subnetwork Access Protocol (SNAP) copies or customer created SNAP copies.

Secondary data protection using enterprise backup technology. Storage I/O latency cannot be guaranteed in a multi-tenant environment. However, volumes with

this profile type will normally have the highest average latency when compared to the other two profiles. These volumes reside on SATA drives only and have the highest Virtual Machine File System (VMFS) to Virtual Machine Disk (VMDK) file ratio.

• Server tiers security: Represents the configuration elements related to the compute tier firewall policies, CMDB, and administrative access.

• Tier availability: Represents the availability configuration elements (no high availability, high availability and disaster recovery).

• Application performance: Represents the performance configuration elements (server monitoring, application monitoring, and end-user response time).


Figure 2 Business Layers and Co-management

The reference architecture, shown in Figure 2, consists of the following logical business layers:

• Cloud application: Represents the external interface with which the enterprise/merchant administrators of the cloud can interact and manage. These administrators are authenticated and authorized at this layer, and have no (direct or indirect) access to the underlying infrastructure. They interact only with the business orchestration layer.

• Business orchestration: Represents both the configuration entities of the cloud and the governance policies for controlling the cloud deployment. It consists of:

Service catalog: Represents the different service levels available and their configuration elements.

Service design: Represents the service level and specific configuration elements along with any policies defined.

Configuration management database (CMDB): Represents the system of record, which may be federated with enterprise CMDB.

Service provisioned: Represents the final configuration specification.

• Service orchestration: Represents the provisioning logic for the cloud infrastructure. This layer consists of an orchestration director system and automation elements for network, storage, security, and server/compute.

• Infrastructure layer: Represents the physical and virtual compute, network, storage, hypervisor, security and management components.

The abstraction of these layers and the security controls built into these layers is critical to helping ensure role-based access control (RBAC) and segregation of duties. All cloud provider administrator accounts are maintained in a central repository and two-factor authentication is used. The different tiered cloud deployments (VPDCs) are available to the enterprise/merchant users/administrators.


The infrastructure layer detailed in Figure 3 below includes the following physical components: storage, storage fabric, servers, firewalls, switches, routers and load balancers. Figure 3 Implemented PCI Measures

Legend: Atop Management Network: VCM: vCenter Configuration Manager; HTA: HyTrust Appliance; N1KV VSM: Cisco Nexus 1000V VSM; VSM: vShield Manager; DSVA: Trend Micro Deep Security Virtual Appliance. Atop PCI Network: CDE VM: Cardholder Data Environment Virtual Machine. At Introspection API layer: FW: vShield firewall; IDS/IPS: Intrusion Detection/Prevention System; AV: Antivirus. At Distributed vNetwork layer: N1KV VEM: Cisco Nexus 1000V VEM. At Hypervisor layer: VMware ESXi. The implemented cloud reference architecture comprises of a cluster of physical servers running a type-I hypervisor (VMware vSphere 4.1 ESXi) that are connected to the physical storage via the storage fabric. These are referred to as “hosts”. Hosts are hardened according to VMware’s hardening best practices using the HyTrust Appliance. Guest VMs (operating systems) are hardened based on PCI standards using vCenter Configuration Manager. Both the hosts and the guests are routinely assessed for configuration drift, and automatically remediated per policy. Agentless anti-malware from Trend Micro’s Deep Security Virtual Appliance protects guest VMs. The Deep Security virtual appliance also optionally provides IDS/IPS functionality adding an additional layer of VM protection. VMs that are part of the CDE can be further protected via an agent in the guest VM that provides comprehensive file and system integrity monitoring and log inspection services. All administrative access, regardless of access method (for example, Secure Shell (SSH) to host, VMware vSphere client to host or VMware vCenter or any of the programmatic or command-line interfaces(CLIs)), is controlled by the HyTrust Appliance (HTA). HTA provides two-factor authentication and role-based access control, virtual infrastructure segregation, root password vaulting, and audit-quality logs for every attempted access.


A distributed virtual switch, such as the Cisco Nexus 1000V or VMware vNetwork Distributed Switch, spans across all the hosts in the cluster and provides three virtual networks for Management, PCI and Forum traffic. The virtual appliances providing infrastructure/management services such as VMware vCenter, vCenter Configuration Manager and vShield Manager, HyTrust Appliance, Trend Micro Deep Security Virtual Appliance and Cisco Nexus 1000V VSM are all connected to the Management network. The CDE VMs with the PCI security measures are connected to the PCI network and the non-CDE VM running the merchant support forum is connected to the Forum network. In-scope CDE system components are required to implement the following PCI security measures as appropriate:

• Network and Web Application firewall • Time synchronization (via NTP) against a secure/reliable time source • File integrity monitoring • Hardened configuration • Role-based access control • Privileged account management • Anti-virus protection • Intrusion detection system/intrusion prevention system • Logging/Audit Trail

Some of these PCI security measures can be implemented in an optimized mode using the introspection APIs available in the hypervisor. These security measures may include, for example, antivirus, network firewall, and intrusion detection and prevention solutions, as shown in Figure 3, which are provided in this case by VMware vShield Manager and Trend Micro’s Deep Security Virtual Appliance.

Conclusion With the PCI DSS version 2.0, system components may be virtual or physical. Detailed guidance on how to adequately secure the CDE with virtual system components is provided by the Virtualization Special Interest Group as an Information Supplement. At a minimum, the hypervisors on which CDE virtual machines (and any other virtual system components) run, are in scope, as is the storage system where the VM image is stored when it is inactive. The virtualized infrastructure components providing services to a CDE-VM, such as network switches, firewalls and other security solutions are in-scope, together with their respective management servers. This means all these components need to satisfy all of the PCI DSS requirements and must be validated. The requirement of one primary function per server can be satisfied even in a virtualized environment, with each VM serving one primary function and the underlying hypervisor providing only the single function of virtualization. The hypervisor must be mature and must be able to demonstrate that it is not vulnerable to any known attacks and exploits, and that it can provide adequate isolation for each VM. Hypervisor configuration needs to be hardened to prevent (accidental) abuse by VMs and administrators. Multi-tenancy and mixed-mode: CDE VMs and non-CDE VMs can be co-mingled on a cluster of hypervisors as long as adequate controls are implemented and validated to ensure proper isolation. However, the PCI SSC recommends keeping in-scope and out-of-scope VM’s on different physical hosts where possible to minimize security risks. Network controls and communication must be tested in the same or similar fashion as physical environments to demonstrate segmentation. Refer to Appendix A for vendor specific detailed controls needed to meet each PCI DSS requirement. Automatic movement of CDE-VMs to other hypervisors in a cluster is allowed. However, it brings into scope the hypervisors and the network over which migration (vMotion) traffic flows. Management and configuration of these capabilities should be carefully controlled due to exposure on the network. It must be authorized to only select administrative personnel. In summary, a PCI-compliant cloud can be achieved with technologies from VMware, Cisco, Trend Micro and HyTrust.


Appendix A: Controls in Place to Meet PCI DSS Requirements The following table lists the controls in place to meet PCI DSS requirements.

PCI DSS Requirement

Unique Risks to Virtual and Cloud

Environments HyTrust Cisco Savvis VMware Trend Micro

Executive Summary

Defining the CDE is particularly challenging in a virtual environment. Every physical and virtual “system component” should be carefully documented. Will this address multi-tenancy environment or use “mixed-mode” deployment? If “other technology” is used to segment systems (such as access control lists (ACLs) on virtual system components) they should be described in detail. The organization should also describe exactly how the system was isolated, how it was tested, and how an auditor can test that segmentation is in place and will remain in place over time. Three separate network diagrams should be available for the assessor: • Data flow diagram of the

CDE • Logical diagram of

physical components. • Logical diagram of virtual

components.

All the in-scope CDE physical system components are subject to all the PCI DSS requirements. If a CDE system component is virtualized then the virtualization platform (hypervisor) it runs on or is connected to is ALWAYS in-scope. Any virtualized infrastructure or security components deployed on the in-scope hypervisor are pulled into scope, as are their management servers. Multi-tenancy (different owners of co-managed CDEs) and mixed-mode (different tiers of technology and/or trust) on a cluster of hypervisors, can be implemented:

• Use of state-of-art, innovative technologies from VMware, Cisco, Trend Micro and HyTrust, and • Technologies, processes and personnel training utilized by Savvis.

The environment can be assessed with proper documentation from the tenant (e-commerce merchant) and the cloud provider, and tested by a PCI QSA skilled in virtualization and cloud computing, such as Coalfire.


PCI DSS Requirement



Requirement 1 Install and maintain a firewall configuration to protect cardholder data.

Most virtual and cloud environments rely on additional technology beyond a standard stateful network firewall to establish separate security zones. Virtual network interfaces cards (vNICs), virtual switches, virtual firewalls, and any other physical components that use software or hardware to create segmentation should be documented and included in section 1, as they are used to establish and maintain segmentation and protect cardholder data from access.

Use the HyTrust Appliance to enforce infrastructure segmentation through label-based policies to prevent administrators from accidentally or otherwise connecting CDE-VMs and Non-CDE-VMs to incorrect portgroups or vSwitchs or virtual networks, and to specify which group of administrators can perform specific change management activities to which virtual network and security components. Any virtualized network (Cisco Nexus 1000V Switch Virtual Supervisory Module) or firewall management servers should be protected against accidental mis-management such as power-off using the HyTrust Appliance. HyTrust Appliance automatically configures protected hosts to accept only administrative traffic originating from it.

Use Cisco Nexus 1000V distributed virtual switch to establish private VLANs to segment CDE-VM and non-CDE-VM traffic. Configure vNIC to access specific port groups on a Cisco Nexus 1000V. Cisco Nexus 1000V is typically configured to span multiple hosts in a cluster. Make sure that the port groups map to the correct physical NICs and upstream physical switches and ports.

Both physical and virtual firewalls and network components are used to segment CDE VMs from non-CDE VM: • Physical perimeter

firewall • Physical Server

tier firewall • Virtual firewall Documented logical and physical network security zones are established.

VMware vShield Edge is an edge network security solution for virtual datacenters that provides essential security capabilities such as stateful inspection firewalling. It can be used to provide a perimeter firewall around a virtual datacenter. VMware vShield App is a hypervisor-based application-aware firewall solution for use within a virtual datacenter. vShield App plugs directly into VMware vSphere to protect against internal network-based threats and reduce the risk of policy violations within the defined security perimeter using application-aware firewalling with deep packet inspection and connection control based on source and destination IP addresses.


PCI DSS Requirement



Requirement 2 Do not use vendor-supplied defaults for system passwords and other security parameters.

The provisioning systems for creating new virtual components must include a way to help ensure that new components are hardened and to remove any default settings.

HyTrust Appliance provides: • Hypervisor root

password vaulting, which includes use of strong passwords and automatic rotation per configured schedule.

• Hardening of hosts and VM-containers based on industry best practices (e.g. Center for Internet Security or VMware hardening guide).

• Monitoring of drift in the hardening posture.

• Automatic remediation of non-compliant hosts.

All CDE-VMs are provisioned with hardened operating systems. Virtualized management servers are segmented onto a dedicated management network and are hardened according to vendor or industry best practices. Hypervisors and VM containers are hardened per custom PCI hardening template, and monitored for drift.

VMware ESXi is used as the hypervisor, which is a type 1 hypervisor, runs on bare metal and serves a single purpose. VMware “host profiles” is used to create templates for host configurations. VMware vCenter Configuration Manager provides: • Hardening of the

VM’s guest OS based on SANS, CIS, NIST and ISO standards to provide PCI compliance for guest operating systems.

• Hardening functionality provided across Windows, Linux, Mac, UNIX, etc.


PCI DSS Requirement



Requirement 3 Protect stored cardholder data.

Memory that was previously stored only as volatile memory can now be written to disk as stored (by taking snapshots of systems). How are memory resources and other shared resources protected from access? (How do you know that there are no remnants of stored data?)

HyTrust Appliance prevents unauthorized administrative access and records all attempted access to VMware ESXi, vCenter, and VM consoles, Cisco Nexus 1000V, VMware vShield Manager and any other virtual management appliance it is configured to protect.

ACL, private VLAN, and anti-spoofing features of Cisco Nexus 1000V are used to protect against man-in-the-middle attacks and maintain network separation of the virtual infrastructure.

SAN security and encryption is used to separate and protect CDE-VMs. CDE-VM backups are encrypted. IDS/IPS data retention is limited and access is restricted to those that need-to-know.

Fully isolate the vMotion network to ensure that as VMs are moved from one physical server to another, memory and other sensitive running data cannot be sniffed or logged. This can be done, for example, by dedicating a VLAN for vMotion that is not routed to any endpoint besides the ESXi hosts.

Deep Security’s IDS/IPS shields guest VM’s unpatched vulnerabilities from attacks and shields newly added VMs automatically with a default security profile.

Requirement 4 Encrypt transmission of cardholder data across open, public networks.

Is any part of the cloud environment considered a “public” network? How are risks to satellite communications, cellular networks, etc. addressed if the environment covers a large WAN?

All traffic between management clients and HyTrust Appliance; and between HyTrust Appliance and protected systems is over an encrypted channel (over SSH or SSL).

• Multiprotocol Label Switching (MPLS) backbone

• SSL/VPN/IPSec used to encrypt all traffic between any two systems (virtual or physical) in the CDE as appropriate.

All traffic between any two systems (virtual or physical) including hypervisor in CDE is encrypted or isolated as appropriate. VMware vShield Edge is an edge network security solution for virtual datacenters. Among other capabilities, it provides site-to-site VPN services.


PCI DSS Requirement



Requirement 5 Use and regularly update anti-virus software or programs.

What components have anti-virus software and how do they report status and help ensure that newly provisioned systems have anti-virus software installed? If a component will not have anti-virus software installed, what is the justification for determining that it is not a system that is commonly affected by viruses?

The management servers of all VMware introspection-enabled solutions are protected by the HyTrust Appliance to ensure administrative access is properly controlled and logged. This provides secondary assurance of the primary controls implemented such as virtual firewalls and anti-virus/IPS/IDS.

CDE-VMs that are susceptible are provisioned with an anti-virus solution.

No anti-virus solution is needed for VMware vSphere host as it is not a general purpose OS and hence is not widely affected by malware. vShield Endpoint specifically enables AV offloading, improves performance by offloading key AV functions to a security virtual machine (SVM) and eliminates the AV agent footprint in virtual machines. This advanced architecture frees up system resources, improves performance of AV functions and eliminates the risk of AV “storms” (overloaded resources during scheduled scans and signature updates).

Deep Security’s Agentless AV solution provides continuous and automated protection for existing and new VMs. Even VMs that have been paused or dormant are automatically protected using the latest pattern files eliminating the possibility of protection gaps.


PCI DSS Requirement



Requirement 6 Develop and maintain secure systems and applications.

This requirement is one of the most critical in the virtual or cloud environment. The process for creating, implementing, and maintaining the virtual or cloud environment is different than for a physical environment. Building images, backing up data, and building disaster recovery and business continuity systems introduce unique risks. How is VM sprawl addressed?

HyTrust Appliance limits who can create, snapshot or clone CDE-VMs, where they can be instantiated, and who can power-off, copy or delete them. A combination of RBAC and labels allows for security policies that can be enforced regardless of where a VM is created, migrated or restored.

With the Cisco Nexus 1000V datacenter teams manage their virtual network with the same security policies and workflow that they use to manage their physical network. This capability reduces recertification and reworking.

Defined business process and automated orchestration for how systems are provisioned and who can provision, create snap-shot of, and clone systems. These systems have automatically hardened images and include all the necessary security solutions (see Figure 3). Also all systems (virtual and physical) are patched and kept-up-to-date using VMware Update Manager. Savvis subscribes to vendor specific vulnerabilities and patch notifications.

All hypervisor hosts should be patched and kept-up-to-date using VMware Update Manager. VMware provides: • Notifications when

critical security vulnerabilities are discovered and patches are made available.

• Guidelines for architecting and hardening virtual datacenters.

VMware vCenter Configuration Manager provides OS and application patching: • Automatically

download bulletins when they become available from OS vendors.

• Assess and deploy patches and automatically verify installation.

Patching functionality across Windows, Linux, Mac, UNIX, etc.

Deep Security’s real-time integration with VMware vCenter enables the automatic discovery and protection of newly added VMs and it’s Agent-less IDS/IPS capabilities ensures that even environments suffering from VM sprawl are shielded from attack.


PCI DSS Requirement



Requirement 7

Restrict access to cardholder data by business need-to-know.

Access controls are more complicated. In addition to hosts, there are now applications, virtual components, and storage of these components while they are waiting to be provisioned. Organizations should carefully document all the access controls in place, and help ensure that there are separate access controls for different security zones.

HyTrust Appliance provides granular RBAC for administrative access to VMware ESXi, vCenter and VM console access, and Cisco Nexus 1000V (Cisco NX OS CLI) based on business need-to-know, skill set, and resource classification. HyTrust Appliance is used to provide two-factor authentication for all administration access to ESXi, vCenter, and VM consoles, and Cisco Nexus 1000V. Every attempted administrative access is recorded (whether allowed or denied).

Cisco Nexus 1000V ACLs and private VLANs are used to zone traffic to and from CDE-VMs to other system components in the environment.

The Savvis portal supports two-factor authentication and granular role-based access to the resources “owned’ by the e-commerce merchant, as shown in Figure 2.

The fine-grained access controls of vSphere limits who can access datastores and networks with cardholder information.

Deep Security’s integrity monitoring and log inspection capabilities ensures that all changes (authorized and unauthorized) are identified and forwarded to a SIEM solution such as RSA Envision or centralized Log Management server in real time.


PCI DSS Requirement



Requirement 8 Assign a unique ID to each person with computer access.

Every action that can affect the security of the virtual/cloud environment should be traceable back to a specific individual.

HyTrust Appliance is configured to use the cloud provider user directory (Microsoft Active Directory) and RSA Authentication Manager , which is where the administrator accounts and their credentials, including two-factor RSA SecurID authentication, are managed. HyTrust Appliance vaults privileged account passwords for all protected hosts. Access to hosts with privileged account status (root) is granted only on a temporary basis to one individual at a time. All activity is logged with the individual user ID enabling traceability of every change to the CDE back to a person.

The e-commerce merchant administrators are provisioned in the Savvis enterprise portal to grant them limited access to perform specific operations to their (virtual) resources. The e-commerce application and support forum is managed within the merchants’ cloud, and is completely the merchants’ responsibility.

Microsoft Active Directory authentication should be used for both vCenter Server and ESXi host management, so that actions can be tied back to individual users. VMware vCenter Configuration Manager provides OS access management: • User account

management (e.g. disable inactive accounts)

• Password policy management (i.e., password complexity, password expiration, etc.)

Access checks across Windows, Linux, Mac, UNIX, etc.

Requirement 9 Restrict physical access to cardholder data.

This requirement is the same for a virtual or cloud environment as for a physical environment, however the risks are greater since physical access to the hypervisor could lead to logical access to every virtual component and storage.

Even with physical access to hypervisors, if root passwords are vaulted in HyTrust Appliance there is an ability to track access and accountability to an individual user.

Physical data center controls restrict who has physical access to the physical hardware and hypervisor console. Restricted physical access to CDE-VM snapshots and offline instances, which are kept on a SAN.

Physical server the hypervisor runs on is in scope.


PCI DSS Requirement



Requirement 10 Track and monitor all access to network resources and cardholder data.

Many virtual components do not have the robust logging requirements of their physical counterparts. Many systems are designed for troubleshooting, and not to create detailed event and system logs that provide sufficient detail to meet PCI logging requirements. Also, PCI requires logs to be stored in a central location that is independent of the systems being logged. (For example, VMware ESXi logs should not be stored on a virtual host on the VMware ESXi server, as compromising the VMware ESXi server could compromise the logs). The logs should be forensically sound.

HyTrust Appliance is used to uniformly track and monitor administrative access to ESXi, vCenter, and VM consoles, and Cisco Nexus 1000V. HyTrust appliance logs who in which role from where, performed what administrative operation on which resource, when, and the result (allowed or denied) for every management access. All log records generated are sent in near real-time to a central log repository that is on a separate physical system and is tamper-proofed.

Without Cisco Nexus 1000V, port statistics are reset each time a VM migrates from host to host using VMware vMotion, with Cisco Nexus 1000V port statistics are persistent, creating a clear audit trail. Auditing tools such as NetFlow and Encapsulate Remote Switched Port Analysis (ERSPAN) are also available and are persistent during VMware vMotion movement.

HP Network Automation Logging and Validating all access and changes made to physical systems.

Virtualization-related administrative operations are tracked by both vCenter Server event auditing and ESXi logging. VMware vCenter Configuration Manager provides OS audit control: • Change logs for the

guest OS for both in-band and out-band changes.

• Verify that audit trails are set up correctly and consistently across all systems.

• Ensure log files are not tampered with by verifying file permissions are set correctly.

• Provide guest OS system logfile monitoring across the environment.

Integration of vSphere with RSA Envision, provides a centralized event management system that supports vCenter, vShield, vCloud, and HyTrust event sources.

Deep Security’s IDS/IPS provides visibility into inter-VM traffic. Deep Security’s Integrity Monitoring provides visibility into unauthorized changes to guest-VMs and provides the ability to monitor log files to ensure they are not tampered. In addition, Deep Security’s Log Inspection feature provides the ability to monitor guest VM operating system and application log files and forward them to a SIEM such as RSA Envision or centralized Log mgmt server in real-time.


PCI DSS Requirement



Requirement 11 Regularly test security systems and processes.

How are scans conducted on virtual components, and how do organizations know that the scans that were run matched the inventory of all systems that were actually running at the time? Are new virtual components scanned before going live?

Host security configuration is defined in templates which are applied to the host prior to deployment in a production network and the host is continually assessed against these templates both on a scheduled basis and after any sort of maintenance or upgrade. Remediation of any configuration drift can be corrected automatically or by administrative staff applying the correct template during a maintenance window.

With Cisco Nexus 1000V testing procedures are the same for the physical as they are for virtual networks, reducing audit complexity and time taken.

Automated network and vulnerability scanning is performed against physical and virtual systems.

VMware vCenter Configuration Manager is used to monitor drift of the VM guest OS configurations, and can be configured to automatically remediate nightly. Alternatively, users can be notified of out-of-compliance events and automatically remediate them on a scheduled basis through the system. Moreover, VCM provides ongoing integrity monitoring for file and directory permissions and checksums.

Deep Security Virtual Appliance can be configured to run automated anti-malware scans and report on file integrity and a multitude of other security-related events. Newly added VMs are automatically protected with default security profiles ensuring consistency of protection.

Requirement 12 Maintain a policy that addresses information security for employees and contractors.

All policies should be updated to include the unique risks of a cloud environment, including policies for forensics, employee background checks, and vendor agreements. Asset tracking processes and system should be updated to account for virtual assets.

HyTrust Appliance policy labels are used to include virtual ‘asset’ information such as owner, contact information, and purpose.

With Cisco Nexus 1000V port profiles and security profiles are maintained centrally in the VSM, and they migrate with each VM during VMware vMotion movement. Also a clear separation of duties can be enforced between the server and network administrators.

Maintain written policy and agreement per 12.8 regarding their responsibility for securing cardholder data.

Deep Security’s security profile model of assigning security policies ensures that consistent security policies are assigned based upon the server type regardless of state or location of the VM.


PCI DSS Requirement



Appendix A Shared hosting providers must protect the cardholder data environment.

Shared hosting providers must be particularly clear about what their responsibilities are for ongoing controls (patching, logging, monitoring, scanning, etc.)


Appendix B: References Payment Card Industry Security Standard Council Data Security Standard https://www.pcisecuritystandards.org/security_standards/pci_dss.shtml PCI SSC Information Supplement: Virtualization Guidelines https:/www.pcisecuritystandards.org VMware Security and Compliance Center http://www.vmware.com/security Cisco PCI Solution 2.0 http://www.cisco.com/go/pci2 Cisco Datacenter Solutions http://www.cisco.com/en/US/products/ps9902/index.html Savvis Cloud Solutions http://www.savvis.com/en-US/infrastructure-services/Cloud/Pages/Home.aspx HyTrust PCI resources http://www.hytrust.com/pci Coalfire Systems PCI Services http://www.coalfiresystems.com/pci_compliance_services.html Trend Micro Deep Security PCI http://us.trendmicro.com/us/solutions/enterprise/security-solutions/server-security/payment-card/

Acknowledgements Authors:

• Hemma Prafullchandra, HyTrust • Ken Owens & Chris Richter, Savvis • Tom McAndrew, Coalfire Systems • Dave Overbeek, Charu Chaubal & Davi Ottenheimer, VMware • Carol Ferrara-Zarb, Bart McGlothin, Rick Simon, Christian Janoff, Cuong Tran & Han

Yang, Cisco Systems • Allan MacPhee & David Silverberg, Trend Micro

We would like to thank the following contributors and reviewers for their invaluable input to make this whitepaper comprehensive and accurate.

• Matt Springfield • Mark Weiner, Reliant Security • Phil Cox, System Experts • Brandon, Eric, Renata, Jason, Will, Julian, Russ & Borya at HyTrust • Lisa Rice & Shefali Chinni, Cisco Systems • Michael Haines & Gargi Keeling, VMware

Disclaimer The information presented in this paper is provided as guidance and was pulled together by the collaborative efforts of the authors. The authors do not accept any liability for any information that is found to be erroneous, incomplete or out-of-date. Best efforts were made to make the information as useful and detailed as possible.

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About Cisco Systems, Inc. Cisco, (NASDAQ: CSCO), the worldwide leader in networking that transforms how people connect, communicate and collaborate, this year celebrates 25 years of technology innovation, operational excellence and corporate social responsibility. Information about Cisco can be found at http://www.cisco.com and http://www.cisco.com/go/pci2. For ongoing news, please go to http://newsroom.cisco.com. Cisco equipment in emerging markets is supplied by Cisco Systems International BV, a wholly owned subsidiary of Cisco Systems, Inc.

About Coalfire Systems, Inc. Coalfire is a leading IT audit and compliance firm that provides audit, security, and compliance solutions for over 1,000 customers throughout North America. Coalfire delivers these services to companies in the retail, financial services, government, healthcare, education, legal, and public electric utility industries. Our solutions are adapted to requirements under emerging data privacy legislation including PCI, GLBA, HIPAA, NERC CIP, SOX, and FISMA. For nearly a decade, Coalfire has experienced consistent growth and profitability each year. We partner with our customers and establish long-term relationships that achieve business success. Coalfire has delivered more than 4,000 successful IT audits truly a proven track record. Coalfire's team of certified IT auditors and engineers has developed an online platform that guides your organization through the challenging task of establishing, assessing, and validating IT compliance with minimal cost and impact to your business today and into the future. Information about Coalfire can be found at http://www.coalfiresystems.com.

About HyTrust, Inc. HyTrust®, headquartered in Mountain View, CA, is the leader in policy management and access control for virtual infrastructure. HyTrust empowers organizations to virtualize more—including servers that may be subject to compliance—by delivering enterprise-class controls for access, accountability, and visibility to their existing virtualization infrastructure. The Company is backed by top tier investors Granite Ventures, Cisco Systems (Nasdaq: CSCO), Trident Capital, and Epic Ventures; its partners include VMware; Symantec (Nasdaq: SYMC); Citrix (Nasdaq: CTXS); RSA (NYSE: EMC) and Intel Corporation (Nasdaq: INTC). Information about HyTrust can be found at www.hytrust.com .

About Savvis, Inc. Savvis, Inc. (NASDAQ: SVVS) is a global leader in cloud infrastructure and hosted IT solutions for enterprises. More than 2,500 unique clients, including 30 of the top 100 companies in the Fortune 500, use Savvis to reduce capital expense, improve service levels and harness the latest advances in cloud computing. For more information, please visit www.savvis.net.

About Trend Micro, Inc. As a global leader in cloud security, Trend Micro develops Internet content security and threat management solutions that make the world safe for businesses and consumers to exchange digital information. With over 20 years of experience, we’re recognized as the market leader in server security for delivering top-ranked client, server, and cloud-based data protection solutions that stop threats faster and protect data in physical, virtualized, and cloud environments. More information about Trend Micro can be found at www.trendmicro.com.

About VMware, Inc. VMware (NYSE: VMW), the global leader in virtualization and cloud infrastructure, delivers customer-proven solutions that significantly reduce IT complexity and enable more flexible, agile service delivery. VMware accelerates an organization’s transition to cloud computing, while preserving existing IT investments and enabling more efficient, agile service delivery without compromising control. With more than 190,000 customers and 25,000 partners, VMware helps organizations of all sizes lower costs, preserve freedom of choice and energize business through IT while saving energy—financial, human and the Earth’s. Information about VMware can be found at www.vmware.com.

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© 2010-2011 Cisco Systems, Inc. and/or its affiliates. Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco's

trademarks can be found at www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1007R)

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No part of this document may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, or otherwise, without the prior written consent of HYTRUST, Inc. This document could include technical inaccuracies or typographical errors. Changes are periodically made to the information herein. HYTRUST, Inc. may make improvements in or changes to the software described in this document at any time. HyTrust, "Virtualization Under Control" and HyTrust logo are trademarks or registered trademarks of

HYTRUST, Inc. or its subsidiaries in the United States and other jurisdictions. All other company and product names mentioned are used only for identification purposes and may be trademarks or registered trademarks of their respective companies.

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