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Gorka Sadowski

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Logs for PCI-DSS in Virtualized Environments

Virtual environments are becoming a reality

The PCI Council just released last month (June 2011) a document on PCI Compliance in Virtualized Environments...  entitled "PCI DSS Virtualization Guidelines" available at

This is an interesting development because it confirms the evolution trend in how specific and granular PCI-DSS is becoming, from the early version of PCI-DSS' Best Practices to these new set of guidelines, the requirements are getting more precise.

Virtual Environments are becoming a reality, even in Financial Institutions, and this is fueling demand for clarification -what to do, and how, in order to demonstrate compliance to PCI-DSS.

The PCI Working Groups structure is validated to be an effective answer capable of producing guidelines to help organizations.

Now, onto the content.

In this document, the PCI Council recognizes that security is even more important and more difficult in Virtualized Environments. Because of the very nature of these nested and interrelated environments, we might be creating holes and security problems where there were none - or less - in the "simpler", true physical world.

Almost like two medications that when taken separately have innocuous side effects and when taken together are dangerous.

As such, and with the aim of keeping an even tighter eye on these infrastructures, this document particularly addresses logs in more sections than just Section 10, for example in sections 3.4 and 5.2. Specifically:

Page 18, Section 4.1.8 "Harden the Hypervisor"

- Separate administrative functions such that hypervisor administrators do not have the ability to modify, delete, or disable hypervisor audit logs.

- Send hypervisor logs to physically separate, secured storage as close to real-time as possible.

- Monitor audit logs to identify activities that could indicate a breach in the integrity of segmentation, security controls, or communication channels between workloads.

- Send logs to separate, secured storage as close to real-time as possible.

Page 32, Section on Requirement 3.4

- Render PAN unreadable anywhere it is stored (including on portable digital media, backup media, and in logs) by using any of the following approaches:

o One-way hashes based on strong cryptography (hash must be of the entire PAN)

o Truncation (hashing cannot be used to replace the truncated segment of PAN)

o Index tokens and pads (pads must be securely stored)

o Strong cryptography with associated key-management processes and procedures

Page 33, Section on Requirement 5.2

- Ensure that all anti-virus mechanisms are current, actively running, and generating audit logs.

Page 37, Section on Requirement 10

- Logging of activities unique to virtualized environments may be needed to reconstruct the events required by PCI DSS Requirement 10.2. For example, logs from specialized APIs that are used to view virtual process, memory, or offline storage may be needed to identify individual access to cardholder data.

- The specific system functions and objects to be logged may differ according to the specific virtualization technology in use.

- Audit trails contained within virtual machines are usually accessible to anyone with access to the virtual machine image.

- Specialized tools may be required to correlate and review audit log data from within virtualized components and networks.

- It may be difficult to capture, correlate, or review logs from a virtual shared hosting or cloud- based environment.

Additional Best Practices / Recommendations:

Do not locate audit logs on the same host or hypervisor as the components generating the audit logs.

In conclusion, it is good to see that little by little, all the ambiguous, unclear and/or left-to-interpretation aspects of PCI-DSS are being iteratively worked on as per Best Practices.

The role of logs in Compliance to PCI-DSS, and the importance of logs to bring clarity and transparency in Virtualized Environments is also outlined and validated.

More Stories By Gorka Sadowski

Gorka is a natural born entrepreneur with a deep understanding of Technology, IT Security and how these create value in the Marketplace. He is today offering innovative European startups the opportunity to benefit from the Silicon Valley ecosystem accelerators. Gorka spent the last 20 years initiating, building and growing businesses that provide technology solutions to the Industry. From General Manager Spain, Italy and Portugal for LogLogic, defining Next Generation Log Management and Security Forensics, to Director Unisys France, bringing Cloud Security service offerings to the market, from Director of Emerging Technologies at NetScreen, defining Next Generation Firewall, to Director of Performance Engineering at INS, removing WAN and Internet bottlenecks, Gorka has always been involved in innovative Technology and IT Security solutions, creating successful Business Units within established Groups and helping launch breakthrough startups such as KOLA Kids OnLine America, a social network for safe computing for children, SourceFire, a leading network security solution provider, or Ibixis, a boutique European business accelerator.