Evan Schuman's StorefrontBacktalk

Jeff Hall is a Senior Security Consultant with FishNet Security and has been a QSA since 2007.

One of the nation’s 15 largest retail chains had done a tremendous job segmenting its network to reduce the scope of its PCI assessment. All of that was thrown away, though, during a simple data center transition, when Networking made a security change but no one ever bothered to tell senior IT management.

Late last year, the chain decided to move its data center from an in-house facility to a purpose-built data center campus in another part of the United States. The goal was to gain additional raised floor space, energy efficiency and to avoid significant natural disaster risks with the location of the existing data center. In the QSA’s review of the new data center, it was seen as a model of energy efficiency and modern design of data centers. So far, so good.

But when the QSA returned for the annual PCI assessment, a review of the core switch and the layer 3 ACLs (Access Control Lists) revealed that all of the switch’s ACLs have been disabled—commented out—for both data centers. The formerly segmented network was totally flat with no segmentation.

The situation had existed since the start of the migration process and would continue for at least another five or six months until the new data center was totally built out with equipment. The reason for this PCI compliance gaff? Networking did it to ensure that production outages did not occur as equipment was migrated from the old data center to the new data center.

The networking group decided to disable the ACLs on the firewalls, routers and switches to accommodate changes to the IP addressing and certain DNS naming conventions that were being implemented with the new data center. From Networking’s perspective, production was more sacred than security. And although a few IT people were informed, no one bothered to brief senior IT management.

From a security standpoint, this was a terrible move as it made the cardholder data environment extremely accessible because everything was suddenly in scope. As a result, the external firewall became the only barrier to the CDE (Cardholder Data Environment). The chain should have never disabled the ACLs. Instead, they should have planned better and adjusted the ACLs to work with the new data center.

Networking’s thinking was that this was a very temporary move. It was not that the network would run forever in this configuration. It was just to be in place during the transition.

From a PCI compliance standpoint, this temporary change was quite problematic. The timing would make the ACLs disabled well past the end of the annual PCI compliance reporting period. A conference call was quickly scheduled with the merchant’s acquiring bank and key card brands to discuss the PCI compliance reporting options. And, yes, there were some serious differences of opinion between the retailer and the QSA.