This is page 2 of:
Windows XP End-of-Life Could Cripple PCI Compliance
Scenario 3: “We don’t know the impact yet, because we have a complicated POS environment.” This group includes any retailer with self-serve kiosks, gasoline pumps or similar environments that run on Windows XP. These kiosks can involve multiple interfaces that connect payment acceptance, receipt printing, product delivery robots (e.g., in a vending machine), display screens and Internet access. That means changing the operating system may be a complicated project. This group of retailers also includes franchisors with a large number of different franchisee environments, where changing an operating system could be far from trivial.
The questions for these retailers include all of those listed in scenarios 1 and 2.
Could retailers just keep their end-of-life Windows XP operating system and develop a compensating control for Requirement 6.1? That approach could be difficult. Retailers are not likely to have either the resources or access to the Windows XP source code to identify new vulnerabilities or to develop their own security patches and then push those patches to the affected Windows XP systems with the same rigor and robustness as the vendor that developed the product originally.
Developing a compensating control would be difficult, because every compensating control requires a risk analysis. In this case, the control would need to reflect a high likelihood of a maximally damaging system compromise. Conceivably, a retailer could combine a host-based intrusion protection system (IPS) with enhanced monitoring and, say, frequent penetration testing. But what is the rationale for needing the compensating control in the first place?
A compensating control is designed for situations where the merchant “cannot meet a requirement explicitly as stated, due to legitimate technical or documented business constraints.” Although merchants have a fair amount of leeway in defining these “constraints,” both the advance notice of Windows XP’s end-of-life status and the number of operating system (and payment application) options argue against this being an easy case to make. Another reality is that any compensating control is only good until the next assessment, which usually is one year. Retailers contemplating this path need to work closely with their QSA and their acquirer before pursuing any type of compensating control strategy.
Windows XP’s upcoming end-of-life may have a subtle impact on the PCI SSC’s list of validated applications. Normally, a PA-DSS validation on a given application version and platform is good for three years, after which a new report on validation (ROV) must be prepared and submitted to the PCI SSC for review and acceptance. Will the PCI SSC accept ROVs for Windows XP payment applications this fall (some of these were originally validated under the expiring PA-DSS version 1.2) for the full three years? A 2016 renewal date would be almost two years past the operating system’s end-of-life date. Similarly, what about currently listed Windows XP-based applications with 2016 expiry dates? I noticed several of these in my pass through the list. Would—or should—the PCI SSC revoke its validation on April 9, 2014, even though there would be two years left on the original validation?
Having raised this question, let me now knock it down. Regardless of an application’s PA-DSS status, if the application is validated and running on an end-of-life operating system, it will not be compliant with PCI DSS Requirement 6.1 and the retailer is not PCI compliant. The fact that the Windows XP version is PA-DSS validated is a technical detail that does not change the facts on the ground.
Do you have Windows XP POS or payment applications? What are your plans for migrating away from Windows XP in the coming year? Or, do you just plan to head to Tatooine and watch both sunsets? I’d like to hear your thoughts. Either leave a comment or E-mail me.