Archive for August, 2017

26
Aug
17

PCI Compliance And Financial Institutions

I remember being at one of the early PCI Community Meetings and someone from the PCI SSC promised that the PCI DSS would be periodically updated to reflect changing business conditions as well as changing threats.  Here we are more than a decade later, and we have version 3.2 of the DSS, but it has been changed more for changes in threats and very little for business.

Their rationale was that they wanted to minimize the number of compensating control worksheets (CCW) that would be needed for the majority of organizations.  This was in response to v1 of the PCI DSS that required that data encryption keys change annually.  Most large merchants who were participating organizations (PO) complained that it was taking six months to a year or more to encrypt their transaction databases and files.  Requiring annual key changes would leave those databases and files at risk because they would always be in a state of perpetual decryption/encryption.  As a result, almost everyone had a CCW for that requirement.  So, the Council changed the requirement to require the changing of encryption keys when they were believed to be compromised or if one or more persons who know the keys leave the company or change roles.

The reason I bring this up is that I have been dealing with financial institutions and their PCI compliance issues for the last few years.  If there is anything more frustrating, it is trying to apply a standard written for merchants to organizations that are not merchants.  It seems like every time I turn around; a requirement needs a CCW, particularly when concerning requirement 3.4.

I am sure the Council will point to requirement 3.2 as their token change that took into account issuers.  But that does nothing for the other requirements that financial institutions struggle.  The biggest reason a lot of the PCI requirements are a struggle is that financial institutions are in the business of; surprise, surprise; processing, storing and transmitting cardholder data.  That IS their business.  3.2 was a great change for issuers, but a lot of the rest of the PCI DSS is a huge pain for a financial institution without a lot of CCWs and the blessings of the requisite card brand(s).

Let us look at a few requirements where CCWs are needed when assessing an FI.

3.4 Render PAN unreadable anywhere it is stored (including on portable digital media, backup media, and in logs) – this can be very problematic for financial institutions.  The reason is that while they can encrypt or tokenize the data, they also need to decrypt/detokenize it as well.  In a lot of cases, they need to do those operations quickly and very often.  It is not that the FIs do not want to protect the information, it is just that they have some unique issues in meeting PCI requirements.

The best example of this situation is debit cards.  Debit cards must be tied to a demand deposit account (DDA) such as a checking or savings account.  That means somewhere there must be a mapping of the debit card into the core application system.  But to process transactions from the card networks when customers use their cards, the PAN must be decrypted/de-tokenized so that the payment can be approved or declined.  This decryption/de-tokenization process needs to meet a timing standard, so adding to the processing time is usually not an option.  As a result, it is not unusual to find that the PAN to DDA mapping file is not encrypted or tokenized.

6.4.3 Production data (live PANs) are not used for testing or development – when part of your business is all about processing, storing and transmitting sensitive authentication data (SAD) and/or cardholder data (CHD), using a few card brand test accounts like a merchant would use for testing is not going to work.  Particularly when you are testing with one of the card brands to certify your application.  In those instances, the FI and brands are going to demand the use of a large and varied set of PANs to ensure that systems are functioning properly.  The only way to do that is with live data from production.

3.2.1 Do not store the full contents of any track (from the magnetic stripe located on the back of a card, equivalent data contained on a chip, or elsewhere) after authorization

3.2.2 Do not store the card verification code or value (three-digit or four-digit number printed on the front or back of a payment card used to verify card-not-present transactions) after authorization

3.2.3 Do not store the personal identification number (PIN) or the encrypted PIN block after authorization.  – requirement 3.2 addresses that issuers that have a business reason to retain sensitive authentication data (SAD) can retain it.  However, 3.2.1, 3.2.2 and 3.2.3 say that all of this data cannot be stored right after authorization. These requirements then go on to say the QSA must inspect incoming transaction data, log data, databases, etc.  Well, guess what?  The incoming transaction data always has SAD in it of some form because the FI has to authorize the transaction.  As I said earlier, databases can have it because of the speed required to authorize.  This is the FIs’ business, yet the standard does not recognize this fact.

The bottom line is that the PCI DSS does not reflect the realities of financial institutions.  As a result, FIs require numerous CCWs to meet the PCI DSS requirements.  As I stated at the beginning, the Council promised that they would address such issues to make CCWs the exception not the rule.  Well, here we are, and in the FI world CCWs are commonplace.  And as we move forward, it will be FIs that will be the focus of the standard, not merchants.  Merchants will very soon be out of the payment card data business altogether with the exception of their POI.  So, it only makes sense to adapt the PCI DSS to securing FIs.

We have separate PCI DSS and AOC documents for service providers.  Maybe we need separate such documents in addition to revised requirements for financial institutions?

Seems like a good discussion topic to bring up at the upcoming Community Meeting.

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18
Aug
17

Why Voice Over IP Matters

“Voice over IP are the most insidious set of communication protocols ever invented by man.” – Jeff Hall

I have been having some interesting conversations of late with prospects and clients regarding Voice over IP (VoIP).  These conversations all seem to revolve around whether or not VoIP is in scope for PCI compliance.  Ultimately the conversation turns to a discussion of why I believe VoIP is in scope for PCI and almost every other QSA seems to never bring the subject up.

The primary reason I believe VoIP is in scope is that the PCI SSC says so.  If you read FAQ #1153 titled ‘Is VoIP in scope for PCI DSS?’ the Council makes it painfully clear that VoIP is definitely in scope if VoIP transmits sensitive authentication (SAD) or cardholder data (CHD).  If you doubt it, here is the exact quote from the first paragraph of that FAQ.

“While PCI DSS does not explicitly reference the use of VoIP, VoIP traffic that contains cardholder data is in scope for applicable PCI DSS controls, in the same way that other IP network traffic containing cardholder data would be.”

Yet even when it is stated that clearly, I still run into people that claim I am making a mountain out of a mole hill and their VoIP is not a risk because other QSAs have never inquired about it.  What that merely means is that other QSAs are ignoring it when they should not be ignoring it.

The first problem with VoIP seems to be that very few people understand it which is the biggest reason in my opinion that a lot of QSAs avoid the discussion.  But it is not just QSAs.  I speak with network administrators, information security personnel and other technology people all of the time and if there is one topic that will glaze over all of their eyes, it is VoIP.  When the discussion turns to VoIP, people seem to hark back to that old PBX system tucked away in the basement or closet.  No one seems to remember that the PBX did get updates (usually two or three a year).  All anyone remembers is that it just worked and that it got replaced once, maybe twice, in a generation.  And the biggest risk was toll fraud from the Caribbean.

But scarier yet is that these people do not seem to completely understand how VoIP and its protocols work let alone the risks.  The biggest problem with VoIP are the protocols used and the reason for my quote at the start of this post.  Regardless of whether you are talking SIP, H.323, H.248, whatever, they all operate the same.  Call set up (start of a call) and call tear down (end of a call) are the only points of a VoIP telephone conversation that are stateful, i.e., conducted via TCP.  The actual call itself is all done via streaming UDP just like any other audio/video stream.  Adding insult to injury, VoIP also requires a large number of the ephemeral UDP ports above 32767 to be open.  UDP, being what it is, provides one of the best transport mechanisms for delivering malware.  There are hundreds of exploits for VoIP from the most benign DDoS attack to turning a VoIP telephone into a spying device by surreptitiously enabling its microphone and video camera (if it has a camera).  But my personal favorites are the attacks that use the VoIP network as an entry point into an organization’s data network.  The bottom line is that the only way to firewall any of the VoIP protocols for actual protection is to keep them away from the rest of your network.

But it can and does get worse.  Add in VoIP trunks from your telephone carrier and you really begin to have a recipe for disaster.  When you have VoIP trunks from your carrier, your internal VoIP network is really only protected from every other VoIP network by the carrier and your call managers.  It is that sad fact that keeps a lot of information security professionals up at night.  If security is all about your weakest link, how do you protect yourself and minimize your risk when your weakest link is essentially the entire world’s phone systems?

Let us add insult to injury in this tale of woe and bring in the concept of unified communications and its primary tool, the softphone.  A softphone is software that turns a PC into a telephone using VoIP. All users need is the internet and a VPN connection to the office network and they have their office telephone right there no matter where they are in the world.  However, the softphone opens up that PC to the same risks that exist for every other phone using that call manager.  But if your VoIP system is used to take calls that discuss cardholder data (CHD), you have now turned that PC with a smartphone into a Category 1, in-scope device because it is now connected to a Category 1, in-scope system and network.  Suddenly all of that effort to achieve PCI scope reduction flies right out of the window.

But this all gets the more fascinating as people go back to their VoIP vendors and find out even more troubling issues with their VoIP solutions.  I remember numerous conversations where people thought once a call was connected to a phone that a call manager was no longer involved therefore the call managers could be put on a different network segment, only to find out that call managers act as bridges when calls are conferenced, involve telepresence or they are to/from outside lines.  They also find out that with the advent of unified communications, services such as instant messaging and email integration are no longer separate servers/functions from the call manager and cannot be easily segmented from the call managers to take them out of scope.

But then there is the revised draft version of the VoIP information supplement from the PCI SSC.  Great guidance if you have a call center.  Worthless for any other sort of implementation of VoIP.  It treats VoIP as a discrete operation as though only the call center model exists for VoIP implementations.  Granted call centers are the largest risk when they are in scope because their call volume is typically 80%+ of calls involving payments.  But all sorts of organizations take payment information over the phone but are not a call center model.

So, what about the organization that has call centers and also normal business people all on the same system?  Based on the information supplement, every phone is a Category 1 device unless the call center VoIP system is separate from the rest of the organization.

Must the call center be on a separate VoIP system from the other users?  It would appear to be that way to manage scope.  But again, there is no explicit guidance for any other implementation model other than a call center.

And if the other users take overflow calls from the call center or occasional calls dealing with PAN, how would separate systems help with that situation?  Near as I can tell, it does not help.

And what about unified communication solutions?  No idea as the information supplement does not reference a unified communication solutions.  However, given the whole premise of unified communications is that it is tightly integrated in most VoIP solutions, other communication methods such as instant messaging and telepresence would likely be in scope as well for PCI compliance.

The bottom line is that the advice I provided over six years ago in this blog is still accurate today.




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