Author Archive for PCI Guru


Do Consumers Really Bail On Breached Merchants?

Conventional wisdom is that when a retailer suffers a breach their customers leave and do not come back. As a result, this threat is what a lot of retail CISOs point to as one of the primary reasons for beefing up information security.

But is that threat real? Do consumers really leave retailers that have been breached?

That is what the Merchant Acquirer’s Committee (MAC) and Dr. Brandon Williams decided they needed to find out. On Tuesday, January 26, 2016, they released the results of their survey they conducted of consumers and their attitude toward retailers that had been breached. I got to speak with Dr. Williams just before the release of the report to discuss what the survey found regarding the issues of retailer breaches.

The good news for retailers that get breached is that while customers tend to avoid a retailer immediately after the announcement of a data breach, those customers eventually return. I was particularly surprised that even with the multiple Michael’s breaches within two years of one another, most customers came back to them.

In discussing this behavior with Dr. Williams, we both came to the conclusion that this behavior was most likely driven by the fact that, unless a consumer suffers identity theft or a loss of money, a breach did not create an incentive for customers to leave a retailer permanently. Yes, a customer most likely received a new credit/debit card because of a breach. Yes, that new card likely created some hassles due to any recurring payments tied to that card. But in the end for most customers, if there was no harm to them therefore there was no foul to the retailer.

My only concern with the results of this study are that it will give some merchants the idea that since a breach does not impact their business they can therefore avoid truly complying with the PCI standards. However, I would remind everyone that their Merchant Agreement contractually obligates them to comply with all relevant PCI standards. So while a breach might temporarily affect business revenue, a breach definitely puts the business on the hook for any fines and penalties levied by the card brands or transaction processors and the costs of any resulting lawsuits. As a result, there should be significant justification for complying with all of the relevant PCI standards.

The full report can be obtained from the MAC web site here.


Unsupported Operating Systems And Applications

One of our QSAs accidentally had their QSA certification lapse and had to go back through in-person QSA training. As a result, all of us in the PCI practice got an opportunity to get caught up on the latest and greatest guidance that the PCI SSC is passing along in their current QSA training. Even though QSAs and ISAs have to go through re-certification training and testing annually, having people go through the in-person training is the only way in some cases to get insight into the latest thinking of the Council.

One of the areas we specifically asked the person to ask their PCI trainer about was unsupported operating systems (OSes) and applications. In the past, such unsupported environments were considered automatically non-PCI compliant because of the ASV automatic failure rules documented in the ASV Program Guide v2.0. As a result, most QSAs constantly get push back from some clients when we encounter unsupported OSes and/or applications. However, we were shocked to find out from our colleague that the Council is no longer advising QSAs and ISAs to automatically mark as non-PCI compliant unsupported OSes and application software unless they are externally facing.

Now before you go off telling management that expensive upgrades are no longer necessary for internal systems and yelling “Alleluia” to the PCI Gods, there are, as you should expect, some caveats to all of this.

First, this is not the Council condoning the use of unsupported OSes and application software. The Council will still tell you that organizations should be using current and supported OSes and application software. This is merely a recognition that upgrades to a supported environment are not always an option in all cases. As a result, organizations might only be able to use unsupported operating systems and applications given hardware and/or customization constraints.

And just so we are all on the same page. Externally facing unsupported OSes and/or application software is still an automatic PCI compliance failure per the latest version of the ASV Program Guide.

Second, in order to continue to use unsupported OSes and applications, your organization will have to create compensating control worksheets for relevant PCI DSS requirements. The first problem with compensating controls is that the controls must go “above and beyond” the controls required by the PCI DSS. So any controls you use to compensate for your unsupported environment must either be not required by the PCI DSS or must go beyond the stated PCI DSS requirements. For example, white listing of installed applications is not a PCI DSS requirement, so that can be used as an effective control. An example of going above and beyond is doing near real-time monitoring of log data because log data is only required to be reviewed daily. For more on writing compensating controls, see my post on the subject.

Which brings up an interesting dilemma depending on the unsupported environment. As a prime example, developing a compensating control for Windows 2000 or Windows ME is probably not going to be possible no matter how many compensating controls you can document in the worksheet. The primary issue that will make this impossible is because of what those older operating systems do to a domain in order to be joined in the domain. The resulting downgrades in security create a litany of issues that no amount of compensating controls will be able to address.

Which points out that just because you make an attempt at compensating controls does not mean that effort will result in something effective or even acceptable to your QSA/ISA. All of those compensating controls for all of the requirements must be in place, operating as designed and assessed as part of your PCI assessment. This is not something you can just toss together at the last minute and hope it will pass muster. As a result, you need to be prepared to admit that there will be instances where the older OSes and/or applications just cannot be compensated for no matter how many other controls you think can implement.

Third, if your organization is going to use unsupported OSes and/or application software, then your organization is going to have to mitigate the risks of this practice. So what mitigations would a QSA/ISA expect to see? Here are a few thoughts.

  • Severely locking down the OS. This is typically done by a utility that white lists the OS and applications on the system. If anything tries to install on the system, it is stopped and an alert is generated.
  • Enabling the generation of all possible log data by the unsupported OS and/or application. Essentially logging all activity from the unsupported OS and/or application. All of this log data feeds the next bullet.
  • Conducting near real time analysis of all log data produced by the unsupported OS and/or application. This will require the use of a system incident and event monitoring (SIEM) solution configured with rules looking for anomalies related to threats to the unsupported OS and/or application. And I can hear people asking now, what are the anomalies I should be looking? See the next bullet.
  • Identification of new threats to the unsupported OSes and/or applications. Threat identification can come from vendors of the unsupported OSes and/or applications as well as from sources such as US CERT, anti-virus vendors and other recognized threat sources. And this is not going to just be some monthly, quarterly or other “periodic” exercise, this is going to have to be an active daily exercise and you will need to prove that it is conducted as such.

And finally do not bother to go through some sort of Rube Goldberg process of bizarre, twisted and convoluted logic you think will get you can pass. There is nothing worse than sending your QSA/ISA through some sort of circular logic that in the end never gets your unsupported OSes and/or applications any closer to being protected than when you started. I have encountered too many instances of a lot of words, pages and diagrams that have no meaning for PCI compliance other than being a lot of words, pages and diagrams all in the hope of baffling the QSA/ISA with a lot of words, pages and diagrams.

All we as QSAs and ISAs ask is that you be intelligent and judicial in what you choose not to upgrade or update.


This Just In – SSL Conversion Deadline Has Changed

This is hot off the presses from the PCI SSC.

I’m not sure I necessarily like this decision, but I can appreciate what is driving it.  That said, I think the better approach would have been to have organizations do compensating controls for keeping SSL around.

Read the update for yourself.


Have You Noticed?

I was on a call with our person who coordinates and does most of our quality assurance (QA) reviews for the firm. They were asked if they had any updates to provide the team regarding PCI. They took over the meeting and had us go to Part 2g of the Service Provider Attestation Of Compliance (AOC). The topic of the discussion was that we needed to make sure that we followed the Note in that section that states:

Note: One table to be completed for each service covered by this AOC. Additional copies of this section are available on the PCI SSC website.”

PCI SP AOC Part 2gThey said that in conversations with other QA people in the PCI arena, this had come up in the discussions as to how he was dealing with the requirement. They said that, until it had been pointed out, they really had not thought about it until just recently when one of our Service Provider clients needed their AOC created and their multiple services necessitated multiple 2g tables.

But that brought up the concern as to how many QSAs and their QA people have noticed this requirement, let alone are doing it correctly? Likely only a few.

However, it is important that the Service Provider AOC gets properly filled out as the service providers’ customers are relying on the AOC to fill out their own matrices based on the service provided by the service provider.

As a result, for every check box checked below in Part 2a, there needs to be a corresponding table filled out in Part 2g.

PCI SP AOC Part 2aIf you are doing service provider assessments and are not following that process expect a big black checkmark in your next PCI SSC AQM review. The question is, will it cause any QSACs to go into remediation?

Happy holidays.


Using SAQ C

There seems to be a lot of confusion over SAQ C and when it can and should be used. SAQ C was developed for the franchise industry, particularly the fast food and small retailer. The idea was that the franchisee would implement the franchise preferred point of sale (POS) solution, connect that POS solution to the Internet and start processing transactions.

Before going any further I must add the following caveat to this post. While I have based this post on all of the training and discussion over the years with the PCI SSC regarding SAQ C, this post is only my opinion and does not mean I am correct. The only official answer is the one you get from your acquiring bank. It is up to your acquiring bank to determine what SAQ your organization should use for your PCI assessment.

To refresh everyone’s memory about SAQ C, the criteria for using SAQ C are as follows.

  • “Your company has a payment application system and an Internet connection on the same device and/or same local area network (LAN);

  • The payment application system/Internet device is not connected to any other systems within your environment (this can be achieved via network segmentation to isolate payment application system/Internet device from all other systems);

  • The physical location of the POS environment is not connected to other premises or locations, and any LAN is for a single location only;

  • Your company retains only paper reports or paper copies of receipts, and these documents are not received electronically; and

  • Your company does not store cardholder data in electronic format.”

The key to understanding SAQ C are the second and third bullets. The third bullet indicates that the POS application cannot be connected to any other locations. The second bullet indicates that the payment application cannot be connected to any other systems within the organization’s processing environment. The bottom line is that the solution must be stand alone and fully segmented away from any other applications and systems.

These criteria can be easily met by solutions such as the MICROS e7 POS solution but can run afoul of integrated systems such as the MICROS RES or other similar fully integrated solutions that offer accounting, timekeeping, order management, inventory and other applications in addition to POS.

The MICROS RES solution can use SAQ C if and only if the POS application can be logically or physically segmented from the rest of the MICROS RES applications. However, in my experience, the MICROS RES and similar applications must operate as a single, integrated solution and segmentation is not possible and therefore SAQ C cannot be used.

Another place where SAQ C cannot be used is where the franchisee is linking all of their locations together back to a corporate office. I encounter this a lot where the franchisee has multiple locations and all of those locations are on a wide area network (WAN) connected to their corporate office. Transactions may be flowing directly out from the retail locations or funneled back to corporate and then out to the transaction processor. Corporate may also be monitoring the local location networks and managing the local locations’ systems and applications.

I also encounter situations where the franchisee is connected to the franchise corporate office for the ordering of inventory and the collection of sales information. The most common occurrences of this situation is with fast food franchise operations and in the lodging industry where locations are connected to the franchise corporate networks for passing information to/from the local systems. The corporate franchise may also be managing and maintaining the franchisee systems as well as part of the franchise agreement. All of these situations also preclude the use of SAQ C.

The bottom line is that SAQ C can only be used in situations where you have a LAN-based POS and no other applications or network connectivity other than to the Internet for the sole purpose of processing transactions.

So what does a merchant do when SAQ C is not an option? Sorry, but in my humble opinion, the merchant version of SAQ D is your only option when you have an integrated POS solution on a network.

Again, as a final reminder, it really does not matter what I think as all of this is up to your acquiring bank to officially approve. I am just giving my thoughts as to how I think things should work based on my training.


Information Supplements Versus The PCI DSS

At various times over the years, the Council has repeatedly told QSAs, Participating Organizations (PO) and anyone else that has asked questions about statements in the Information Supplements the following.

“Information Supplements only offer guidance to organizations and do not replace or supplant anything stated in the PCI DSS.”

So what are the point then of the Information Supplements?

Boy is that a good question. As a QSA, I often ask myself that very question after some of the inane conversations with clients and prospective clients regarding Information Supplements and their supposed “guidance”.

The first thing everyone should remember about Information Supplements is that they are developed and written by a committee at the suggestion of the Council, POs or as part of special interest work groups. These committees are made up of personnel from interested POs, QSAs, ISAs, vendors and anyone else willing to participate in their development. They are edited by a representative from the Council and reviewed by the Committee and are then submitted to all POs, QSAs and ISAs for review and comment. Similar in concept to the development and review of RFCs by the IETF.

The other key point about Information Supplements are that they are developed to give QSAs, ISAs and organizations ideas and guidance on how best to appropriately meet the requirements of the PCI DSS and the Reporting Template testing. Again, as the Council has repeatedly stated, the Information Supplements do not replace the explicit guidance and testing requirements in the PCI DSS and the Reporting Template. They are merely suggests on an approach.

Yet time and again, QSAs and ISAs get these priceless documents tossed in our faces and are told we do not know what we are talking about. “The Information Supplement says …” is always put out there as the justification as to why an organization is doing something it should not be doing or as the rationale for why the organization is not in compliance with the PCI DSS. And we again are forced to explain that the Council never has said that an Information Supplement replaces the guidance and testing in the PCI DSS or the Reporting Template.

The first question anyone, and I do mean anyone, should ask about any statement in an Information Supplement is, “Does the PCI DSS and/or the Reporting Template explicitly say the same thing?” Those are the only two documents that matter and the only documents that your organization will be assessed against. If it is not explicitly called out in either of those documents, then it is not accurate and does not reflect the compliance requirements.

As an example. I was on a conference call recently regarding the Council’s Information Supplement on penetration testing. This supplement was issued in March, 2015 and is possibly one of the most confusing and contradictory pieces of “guidance” we have ever encountered. In fact, it has created more confusion than it has actually clarified. In my very humble opinion, the Council would be better off taking it out of circulation because of all of the trouble it creates for QSAs, penetration testers, ASVs and clients. It is possibly one of the worst written of the Information Supplements and, while people both on the Committee that developed it and externally supplied the Council with numerous suggestions for changes, those changes were not incorporated into the document. Why those changes were not incorporated is anyone’s guess. But we in the PCI community ended up with possibly the worst expressed and misunderstood guidance available.

As usual, the client was arguing over the scope of their penetration testing. I get the fact that organizations want to minimize costs and scope as much as possible. However when you listen to some security professionals arguments on this topic, you just wonder how they got to their positions as they argue over not testing systems and devices that are painfully obvious to be in scope.

And as also is usual, the first piece of confusion regarding scope is in Section 2, page 5, first paragraph after the bullets and states the following.

“It is not a requirement to test from within the CDE to the servers inside the CDE; and testing exclusively from within the CDE perimeter will not satisfy the requirement. However, when access to the CDE is obtained as a result of the testing, the penetration tester may elect to continue exploring inside the network and further the attack against other systems within the CDE, and may also include testing any data-exfiltration prevention (data-loss prevention) controls that are in place.”

One would think that to any reasonably intelligent information security professional, the first part of the sentence, “It is not a requirement to test from within the CDE to the servers inside the CDE;” would be considered a pure line of garbage. Never mind that none of the recognized penetration testing methodologies ever suggest such an approach. But people arguing never consider that fact. Nope. The people arguing are so focused on cutting their PCI compliance bill that it does not matter that the statement is pure and unsupported garbage. It is considered the gospel truth. Otherwise, why would the Council allow such a statement? Good question. We have asked the Council that question and the answer back is? You guessed it.

“Information Supplements only offer guidance to organizations and do not replace or supplant anything stated in the PCI DSS.”

Again, never mind it is in no way supported by the guidance provided by the PCI DSS for requirement 11.3 which says:

“The intent of a penetration test is to simulate a real-world attack situation with a goal of identifying how far an attacker would be able to penetrate into an environment. This allows an entity to gain a better understanding of their potential exposure and develop a strategy to defend against attacks.”

But argue that point they do even when you point out that arguing this point is basically arguing that any attacker would stop at the perimeter of the CDE and would go no further.

Seriously? If you believe that fact, you must also believe in Santa Claus, the Easter Bunny, the Tooth Fairy and any other of the multitude of mythical fictional creatures. Or you are just lying to yourself and are in serious denial about your organization’s security posture. But argue on they do.

Then you pair that to the second part of that first sentence of this paragraph that says, “… and testing exclusively from within the CDE perimeter will not satisfy the requirement.” Just adds to the out of scope argument.

As I point out when bitch slapped with this terrible writing, if you go back and carefully re-read the second part of the first sentence, what it points out is that penetration testing from only inside the CDE is not sufficient to meet the penetration testing requirements of the PCI DSS requirement 11.3. In no way does that sentence say or even further imply that the CDE is out of scope. It is actually saying that penetration testing should be done from within the CDE, but that penetration testing only inside the CDE does not meet 11.3. But people will still argue that the CDE is out of scope.

That the CDE is in scope is further supported by the definitions of “critical systems” from section 2.2.1 of the document which defines that not only are systems within the CDE in scope, but also those that are outside the CDE but could affect the security of those systems inside the CDE (i.e., what the Council and the Open PCI DSS Scoping Toolkit refer to as “connected to” systems). However, people arguing over scope rarely, if ever, tie these two section together and then argue that because they are in separate sections they cannot be possibly together even though the entire document is about only one subject, penetration testing and requirements in 11.3 of the PCI DSS.

So before you go off telling your QSA or ISA that the Information Supplement says something. Think about what the information supplement says. Is the guidance from the Information Supplement even implied in the PCI DSS? Read the guidance in the PCI DSS and the testing procedures from the Reporting Template. If the PCI DSS or the Reporting Template do not explicitly have the same language in them that the Information Supplement has, then the Information Supplement is merely a suggestion.

And if the guidance from the Information Supplement does not make sense, pull your head out of your posterior and use some God given common sense. Ask your QSA or ISA to explain it, before going off halfcocked and thinking that someone could actually think such things made sense.

But again, why would the Council allow such statements? Good question. We have asked the Council that question and the answer back is? You guessed it.

“Information Supplements only offer guidance to organizations and do not replace or supplant anything stated in the PCI DSS.”

Clear as mud? You bet.

But what did you expect? It is PCI.

For all of you in the United States, have a happy and safe Thanksgiving holiday.


Small And Mid-Sized Businesses

At this year’s PCI Community Meeting, the push was to address the security issues faced by small and mid-sized businesses, otherwise referred to as SMB. However, in my opinion, the approaches being suggested are still too complex. Great security results from simplicity, not complexity. As a result, I propose the following approach for SMBs because SMB executives typically have little time to fully educate themselves in information security, let alone, PCI. And while I am of the opinion that executives should have such knowledge, it is just not happening.

There Are No “Silver Bullet” Solutions

First and foremost. There are no “silver bullet” solutions that will entirely remove your organization from PCI scope. Any vendor telling you that their solution removes your organization from PCI scope is lying to you. If you hear such a statement from a vendor, the vendor does not know what they are talking about and their statements regarding PCI should no longer be trusted. The bottom line is that, if your organization accepts credit/debit cards for payment for goods/services, the organization will always have some PCI scope. The least amount of scope an organization can achieve is complying with the requirements listed in the SAQ A. There is nothing less. Anyone telling you otherwise does not know what they are talking about.


This is probably the biggest single thing an SMB can do. In this day and age, there is no reason that any organization needs to retain CHD. Period. The most common business justification is that the organization does recurring transactions and that is the reason to retain CHD. Processors have a solution for that situation and many others. So I say it again. There is no valid business reason for any organization to retain CHD. None. Nada. Zip.

The first question out of an SMB executive’s mouth to a payment solution vendor should be, “Does your solution store cardholder or sensitive authentication data?” If the answer is anything other than an immediate and definitive “NO”, the meeting or telephone call is over, done, complete. There is nothing more to discuss. SMBs must stop being an easy target for attacks. The easiest way to do that is not having the CHD in the first place.

The second question that a payment vendor should be asked is, “How does your solution minimize my organization’s PCI scope?” If the vendor cannot provide you with a whitepaper on this subject, run away. If the documentation provided by the vendor leaves you with more questions than answers for PCI compliance, you also need to run away. In all likelihood, if this is what you encounter, the vendor’s PCI compliance is questionable, complex or requires too much effort on your part to be PCI compliant. This question should result in a one to three page whitepaper on PCI and how the vendor’s solution minimizes your organization’s scope.

So what solutions reduce scope to the minimum?

If you are a traditional brick and mortar retailer, end-to-end encryption (E2EE) from the card terminal, also known as the point of interaction (POI), to the transaction processor. PCI has a validation program called point-to-point encryption (P2PE). P2PE solutions are independently validated to ensure that they are secure. Solutions such as Shift4’s Dollars on the Net, First Data’s TransArmor and Verifone’s VeriShield are E2EE solutions that could meet the P2PE standard, but for various reasons the providers chose not to validate them to the P2PE standard. The key capability for any such solution is that the solution encrypts the CHD/SAD immediately when it is read from the card and none of your organization’s technology can decrypt the information and therefore read it.

If your organization does eCommerce, then you want to use a redirect or iFrame to process transactions in order to reduce PCI scope. The best example of a redirect is when a merchant uses PayPal for processing payments. The merchant’s Web site has a PayPal button that sends the customer to PayPal who then processes the customer’s payment transaction. At no time does the sensitive authentication data (SAD) encounter the merchant’s Web site. One of the concerns from merchants about redirects is the myth that customers vacate their shopping carts because they are redirected to a different site for payment. While this was true in the early days of eCommerce, with the increased use of PayPal and similar payment services, customers seem to have gotten over that practice and vacated shopping carts are no longer an issue. But if this is still a concern, use this as a teaching moment and educate your customer base that you do the redirect to ensure the security of their SAD.

An iFrame is essentially a Web page within a Web page. But the key thing from a PCI compliance perspective is that the iFrame is produced and managed by a third party, not the merchant. An iFrame can be a Web page, but more often than not it is a series of fields that gather the SAD for conducting a payment transaction. As with the redirect, the SAD never comes into contact with the merchant’s Web site.

Both of these solutions take your organization’s Web site out of scope so you do not need external and internal vulnerability scans and penetration tests. However, just because your Web site does not have to go through the rigors of PCI compliance, you still need to ensure its security. See my post on SAQ A and SAQ A-EP for a more detailed discussion on this topic.


Tokenization is the act of encrypting or tokenizing the primary account number (PAN) so that when it is returned to the merchant for storage it has no value to anyone if it is disclosed. Tokenization can occur at the time a card is swiped or dipped at the terminal or it can be done by the transaction processor at the back end of the transaction. Regardless of where the tokenization occurs, paired with E2EE or P2PE, tokenization further minimizes PCI scope.

If your organization needs to perform recurring transactions such as with subscriptions or automatic reorders, tokens can be generated by the processor so that they can be used just like a PAN. While a token is not a PAN, in situations where they can be reused for future transactions, it is incumbent upon the merchant to protect access to the token so that it cannot be sent to the processor for fraudulent charges.

And that is it. Not storing CHD, E2EE/P2PE and tokenization will reduce an organization’s PCI compliance footprint to the absolute minimum. It really is that simple. However, finding the solutions that bring all of that to the table is where the work comes in. However, any SMB that asks the right questions of its vendors can put together a solution that minimizes their scope and provides protection for CHD/SAD as good as with the big boys.


If you are posting a comment, be patient, as the comments will not be published until they are approved.

If your organization has a PCI opportunity, is in need of assistance with a PCI issue or if you would like the PCI Guru to speak at your meeting, you can contact the PCI Guru at pciguru AT gmail DOT com.

I do allow vendors to post potential solutions in response to issues that I bring up in posts. However, the PCI Guru does not endorse any specific products, so "Caveat Emptor" - let the buyer beware. Also, if I feel that the response is too "sales-ee", I reserve the right to edit or not even authorize the response.


February 2016
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