Archive for March, 2011


PCI SSC Updates The ASV Program and Issues New Information Supplement

March 2011 has been a busy month thus far for the PCI SSC.  On Thursday, March 10, they announced a new ASV training program and on Friday, March 18, they released an Information Supplement on protecting telephone-based cardholder data.

The ASV training program has blindsided the ASV community as it was a total surprise.  Yes, there has been talk over the years at the Community Meetings and in other venues regarding ASV qualifications and training, but nothing ever seemed to come from those discussions.

According to the press release, the ASV training program, “… is a direct response to the feedback we’ve received from the merchant community …”  One can only assume that the complaints that have been voiced about ASVs from merchants and service providers as well as the comments in the media have finally caught the attention of the PCI SSC and they are going to address the problem with training.

The consistent complaint I have heard from clients over the years was in regards to the fact that no two ASVs ever scoped their network the same for vulnerability scanning.  The next most common complaint was always about the different results of the vulnerability scanning which was most often voiced after a company changed ASVs.  While there are always some bad apples in the bunch, I do believe that most ASVs know what they are doing.

As a result of all of this, I am sure this new training requirement is to address the complaints and make the program better.  This training is in addition to the network security test ASV companies already had to pass.  For those of you that did not know, ASVs have to conduct network security scanning against a test network with predefined vulnerabilities operated and configured by the PCI SSC.  ASVs are expected to produce a sample ASV report and document all of the predefined vulnerabilities.

The ASV training is comprised of an eight hour online course and an examination.  A minimum of two employees are required to take the course and pass the examination.  Once this has been accomplished, the organization is designated as having Qualified ASV employees.  As with a lot of PCI requirements, there are some important dates involved.  ASVs that are renewing their status prior to June 1, 2011 need to get two personnel trained and passed the examination by June 15, 2011.  ASVs that will certify after June 1, 2011 need to have two staff trained and passed the examination by their renewal date.

Given the additional cost of this new training plus the requirement to have a minimum of two people trained, it will be interesting to see if any of the existing 130 ASVs drop out because of this new requirement.

Telephony Cardholder Data

The other issuance of interest this month was in regards to telephone conversation recordings that contain cardholder data.  While this is a longer dissertation on FAQ 5362, there is really nothing new presented in this information supplement.  The bottom line still is that if you have call recordings that contain cardholder data you are required to either; (a) do not record it in the first place, (b) if recorded, redact it if possible, or (c) make sure that it cannot be searched, is encrypted and access is restricted.  The best thing about this information supplement is the flowchart that was created for this situation.



Just got a call regarding PCI and Sarbanes Oxley (SOX) compliance.  Whether it is SOX, the Health Insurance Portability and Accountability Act (HIPAA), Gramm Leach Bliley Act (GLBA) or some other regulation, organizations that also have to comply with the PCI standards want to maximize the work effort to avoid redundancy.  After all, all of these assessments take a lot of effort to gather the documentation and other supporting materials as well as interviews and the like to go through the various assessments.  It is not that this cannot be done, but it can get complicated to ensure efforts are coordinated properly and assessment work done by one party is acceptable to the QSA and vice versa.  It has been my experience that properly planned, a lot of these other assessment programs can be aligned to minimize the amount of effort required to go through a PCI assessment.  However, be advised that there may still be a significant amount of effort on your QSA’s part as well as your own organization because of the testing required by the PCI DSS.

For example, since the release of SOX there have been a lot of changes, particularly for section 404 where most public companies think they will gain leverage.  What has happened is that with the changes to 404, the number of applications in-scope for SOX has been greatly reduced as has been the testing requirements.  Therefore what is in-scope for SOX is usually a very small subset of what is in-scope for PCI or may not even be relevant to an organization’s PCI compliance.  I know this will seem hard to believe, but we have publicly held clients where their point of sale (POS) is not in-scope for SOX.  As a result, any leverage between SOX and PCI efforts is not always possible.

But that is not to say there are not areas where leverage can be obtained.  One place where we typically get leverage is with the assessment of logical access controls, PCI DSS requirements 7 and 8.  Since most companies have a central directory for managing users such as Microsoft Active Directory, logical access controls get fairly well covered under SOX, HIPAA or GLBA.  As such, an organization’s internal audit function and/or external auditors have covered how users are added/changed/disabled/deleted, password aging, password strength, etc.  There may still be areas that were not covered such as password resets, but there is no reason to go back over what has already been covered if that was already assessed and the parameters of their assessment meets or exceed the PCI DSS requirements.  In most cases, we find that the assessment by the other party typically goes above and beyond what the PCI DSS requires.

Another area we find where leverage can be gained is with application development standards, PCI DSS requirement 6.3, and change control, PCI DSS requirement 6.4.  Both of these areas get quite a bit of scrutiny under SOX, HIPAA and Federal Financial Institution Examination Council (FFIEC) regulations as well as most organizations’ internal audit work programs.  Granted, these various assessment efforts will not cover every application or device in-scope for PCI.  However most organizations have common policies, standards and procedures for application develop and change control and those will have been assessed and tested under other assessments.  These assessments should be able to be leveraged and minimize a QSA’s testing to in-scope PCI items that were not tested as part of other assessment efforts.  Again, in most cases, we find that the assessments of these areas go above and beyond what the PCI DSS requires.


Now before everyone runs joyously off to limit their QSA’s review activities, there are some caveats that need to be considered in order for this to be effective.

First and foremost of all of these caveats is that it is up to the QSA to be willing to accept the other parties’ work efforts in assessing the requirement in question.  The PCI SSC has made it clear that a QSA is under no obligation to accept any third party’s assessment efforts, even another QSA’s.  As a result, just because you have these other assessments does not mean that you will gain anything in your PCI assessment.  Which leads me to recommend that when you are assessing QSAs for your PCI compliance work, it is a good idea to ask them about whether or not they will accept other third parties’ assessment work?  You cannot leverage the results of these other assessments if the QSA will not cooperate.

Another caveat is that the assessment efforts from any third party must have occurred within the PCI assessment period.  No one should expect a QSA to rely on a work product that did not occur during the PCI assessment period.  I have run into situations where, because of timing, the assessment of logical access occurred a few months prior to the PCI assessment time period and would not be re-assessed by the organizations until a month after the PCI assessment period.  In those cases, we have had to conduct our own testing of logical access controls and could not leverage the other auditor’s work.  I also have had run into instances where the assessment of a particular control occurred right at the start of the PCI assessment period.  Because almost a year had passed, we opted to conduct some limited testing of the control to ensure that the control was still functioning as designed but did not conduct our full testing because of the results of the prior testing.

A third caveat is that the QSA needs to be careful in determining what was covered by the third party in their assessment.  Not that we have had organizations trying to put one over on us, but as a QSA you really need to read the third party’s report and, if necessary, ask questions about the scope of the assessment.  We have found in a number of instances that what was represented by our client and the work performed by the third party were not the same.  The reason this occurs is that what we (QSA) asked for; what our client contact then asked for; what the person who has the report supplied; do not always jive with what we (QSA) were expecting or requested.  As a result, it is not unusual to have to go a couple of iterations to get what we need.  And even then we may find out that what we can get will not meet our needs.

The final caveat is that the third party must be qualified to conduct the testing you are going to rely upon.  This is similar to the requirement that the PCI SSC tells QSAs about for internal vulnerability scanning and penetration testing.  Per my earlier example, if an organization’s external auditor has done testing regarding how users are established and assigned access to the network and applications, there is little to be gained from a QSA going through the same exhaustive testing.  As an employee of a public accounting firm, I can tell you that SOX testing is not a small effort in regards to logical access.  So unless the logical access testing totally missed the cardholder data environment, I would typically have no trouble relying on the external auditor’s assessment.

So there are ways to leverage other compliance efforts to reduce the impact of PCI compliance work.  In order to leverage all of these efforts, quite a bit of planning and coordination are required.  And just because you can do this, does not automatically mean that the leverage gained outweighs the effort required to make it happen.  So you need to keep in mind that such efforts may be for naught.


PCI And Virtualization

I just received an invitation for a Webinar on Virtualization and PCI compliance.  My friend, John Kindervag is one of the panelists and, no, this is not an unpaid advertisement for anyone to attend even though I have provided the link to register.  For an hour they will be discussing this topic because now the PCI DSS v2.0 references virtualization.  Let us be very clear, while the PCI DSS prior to v2.0 never explicitly discussed virtualization, QSAs were instructed on how to approach virtualization security.  And as you will see, virtualization security is no different than any other operating system security.

In my very humble opinion, virtualization is a one minute security issue, if that long.  Let us cut to the chase, as small an attack vector virtualization can be, it is still a potential attack vector, so you need to secure it.  Is that clear enough?  The real issue is how to secure a virtualized environment.

There are two different forms of virtualization.  There are stand-alone hypervisors (what NIST refers to as “bare metal”) like VMware vSphere, VMware ESXi, Microsoft Hyper-V and Citrix XenServer.  Bare metal hypervisors are what we typically run into the most in our PCI compliance engagements, but not necessarily a guarantee.  There are also VMware Server, VMware Desktop and Microsoft VirtualPC (what NIST refers to as “hosted”) that require a host OS to run on as an application no different than Microsoft Word.  Obviously, the attack vectors are wildly different for each type of virtualization.

For whatever reason, it seems that a lot of IT professionals do not recognize that a hypervisor is an operating system.  Yes it is a very specialized operating system, but it is an operating system just like Linux or Windows.  Most hypervisors are based on Linux or UNIX and have a few security hardening similarities.  But given a hypervisor’s specialization, they have significantly different security hardening requirements from their Linux or UNIX counterparts.  As such, hypervisor vendors typically provide a security hardening standard for each of their hypervisor operating systems.  All you need to do is go to the hypervisor vendor’s Web site and download the security hardening guide for your version of hypervisor.  Which brings up a good point, if your hypervisor vendor does not provide a security hardening guide, then you need to find a different hypervisor.

For bare metal implementations, the only thing you have to secure is the hypervisor itself.  However, with hosted virtualization, you need to secure the host operating system as well as the hypervisor.  In addition to the hypervisor, you will need to follow the host operating system vendor’s security hardening guide to ensure that the host OS is also secure.

But hardening your virtualized operating system is not the end of the job.  You need to properly implement your virtualized environment securely as well and that is more than just hardening the hypervisor.  The most obvious security item that needs to be done is that any guest operating systems implemented need to also be securely hardened.  It still surprises me the number of IT professionals that somehow seem to think that because they are implementing Windows or Linux as a virtual machine that there is something different about security and you can totally skip or skimp on hardening.  Security hardening procedures need to be completely followed regardless of whether the guest OS is stand-alone or in a virtual machine.

The next area that seems to get the short shrift is infrastructure security.  This is particularly true of the management of the hypervisor environment.  Most implementations I have seen do a good job of securely connecting the virtual machines, but the hypervisor infrastructure environment leaves a lot to be desired from a security perspective.  The first mistake I see is that the hypervisor management environment is not segregated from other networks.  In the first scenario I commonly see, the production network and the hypervisor management network are on the same segment.  If an attacker compromises any virtual machine, they gain access to the hypervisor management environment and can therefore gain access to the virtual cardholder data environment.  In the other scenario, the corporate network and hypervisor network are one and the same and therefore everyone that is on the corporate network can also gain access to the hypervisor management network.  The way to fix both of these situations is to put the hypervisor management network on its own network segment.  I also recommend to organizations that they dedicate a NIC to only that segment.  However, if an organization already has an operations management network segment separate from other networks, I have no problem having the hypervisor management network in that segment as well.

The other scenario I frequently see is virtual machines from the cardholder data environment (CDE) intermingled with virtual machines that are not part of the CDE.  The problem here is that in the event of a compromise of a non-CDE virtual machine, CDE virtual machines may be accessible because of the configuration of the virtualization environment.  The best way to use virtualization for PCI compliance is to isolate your CDE virtual machines in a physically separate virtual environment from your non-CDE virtual machines.

For the truly paranoid, you can also fiddle with parameters such as physical/logical NIC assignments as well as SAN configurations.  While these sorts of configuration changes can provide additional security to the equation, I have my doubts as to the significance of these changes from a security perspective.  In my years of dealing with virtualization, these sorts of configuration changes have been more for performance reasons and enhanced security was just a nice byproduct.

Finally, there is the maintenance aspect of virtualization.  I think everyone gets the fact that virtualized or not, the guest operating systems need to be maintained and patched just like their stand-alone brethren.  However, when you ask organizations how often they patch their hypervisor; some will say to you very honestly, “You have to patch it?”  Earlier on I stated that a hypervisor is also an operating system and, as such, it needs to be patched just like any other operating system.  Granted a hypervisor does not usually get patched every month like Windows, but there are patches issued every so often by hypervisor vendors.

Best of luck to John and the round table that are presenting this month on virtualization and PCI compliance.  Hopefully this post will help explain what they will be discussing as well as lead to more insightful questions on the topic.


PCI Logging Reference

I often get asked for great references for documents that support the compliance with the PCI standards.

Recently, Dr. Anton Chuvakin completed a long (18 parts) dissertation on what it takes to conduct a complete, PCI DSS compliant log review.  It has taken me this long to read the whole thing, but I have to admit, I doubt he has missed much of anything.

A client I was working with passed along the whole set of postings and asked me my if it would be good to pass along to their logging and monitoring group as a reference and I had to say that I wholeheartedly agree.

I highly recommend that you read this set of posts to obtain an understanding of logging, why it is important and what constitutes a review.

Welcome to the PCI Guru blog. The PCI Guru reserves the right to censor comments as they see fit. Sales people beware! This is not a place to push your goods and services.

March 2011