The steps comprise platform-hardening, configuration and change management, administrative access control, network security and segmentation, and audit logging.
"It's a good idea to talk about the intersection between compliance and security. A lot of compliance regulations are written assuming the systems are physical -- and that only certain administrators have rights to physical systems," says Jon Oltsik, senior analyst at Enterprise Strategy Group. "What if financial information sits on a virtual system and on a system with other [applications running on it]? If a financial application runs as a VM on a physical system, where do the access controls need to be? How are the regulations going to change to accommodate that?"
And compliance doesn't always equal security -- just take a look at some of the biggest data breaches of late. Virtualization adds another dimension to that problem.
"You can have compliance without security and security without compliance," Oltsik says. "RSA doesn't want compliance to be just a check-off box. Rather, it wants to see good, strong, auditable controls that provide both" in a virtualization environment, he says.
"I think this is a good start," he says.
Here are RSA and VMware's five steps for securing virtualized environments and meeting compliance requirements:
Configure the virtualization platform, both the hypervisor and administrative layer, with secure settings, eliminate unused components, and keep up-to-date on patches. Virtualization vendors have their own hardening guidelines, as does the Center for Internet Security and the Defense Information Systems Agency, according to RSA and VMware.
"Virtualization infrastructure also includes virtual networks with virtual switches connecting the virtual machines. All of these components, which, in previous systems, used to be physical devices are now implemented via software," states the RSA and VMware best practices guidelines. "Virtualization also introduces a new administrative layer for managing the virtualization infrastructure. To reduce the risk of unauthorized access, just as with physical systems, the hypervisor layer and the administrative layer must be properly 'hardened.'"
2. Configuration and change management.
Extend your current change and configuration management processes and tools to the virtual environment, as well.
"Pay special attention to the speed of changes enabled by virtualization, VM mobility, and offline VMs coming online," the paper says. "Ensure that patch management practices extend to the virtualization software in addition to the virtual machines."
3. Administrative access control.
Server administrators should have control over virtual servers and network administrators, over virtual networks, and these admins need to be trained in virtualization software in order to avoid misconfiguration of systems.
"Careful separation of duties and management of privileges is an important part of mitigating the risk of administrators gaining unauthorized access either maliciously or inadvertently. Depending on the sophistication of the virtualization software, it is possible to define specific roles and granular privileges and assign those to individual administrators," the report says.
And only allow authorized administrators admin access to the hypervisor. It's best to disable all local administration of the hypervisor and provide it via a central management application.
4. Network security and segmentation.
Deploy virtual switches and virtual firewalls to segment virtual networks, and use your physical network controls in the virtual networks as well as change management systems. Be sure that machines handling protected data are isolated, and deploy virtual IDS/IPSes.
PCI DSS doesn't directly state whether virtual machines processing cardholder data can be placed on the same physical server as virtual machines that do not handle that type of data.
"Organizations should work with their auditors to demonstrate how they plan to securely segment their network, including their specific use of the virtual network segmentation technologies. Depending on the applications and current security posture, organizations and auditors can work together to determine the acceptable mix of virtual and physical network segmentation to isolate in-scope systems," the paper says.
5. Audit logging
Monitor virtual infrastructure logs and correlate those logs across the physical infrastructure, as well, to get a full picture of vulnerabilities and risks. Adapt automated tools and SIEM systems to integrate logs from both environments.
Enterprise Strategy Group's Oltsik says he'd add a couple more best practices to the list. "I'd add to separation of duties to define a lot of the administrative privileges and make sure there isn't any root access," he says. "You want to audit access control."
And start monitoring traffic between VMs. That way, "you can start to understand how the virtual world shakes out versus the physical world," he says. "There's going to be a hybrid of them over time."
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