On June 30, another refresh of the Payment Card Industry (PCI) Data Security Standards (PCI DSS) will upgrade Web application security testing from a best practice to a mandatory practice. The deadline forces merchants and vendors to take a closer look at application-layer security and emphasizes its importance in fighting increasing online threats.

The Payment Card Industry Data Security Standards were developed by the five leading payment card brands – American Express Co., Visa International, MasterCard Worldwide, Discover Financial Services LLC, and Japan-based JCB International Credit Card Co. Ltd - now organized as the PCI Security Standards Council, to ensure the protection of consumer credit card information and to set a global standard for security.

Customer trust is critical to a company’s bottom line, particularly when the company relies on e-commerce and online credit card transactions, and privacy and security issues are a real concern for today’s consumer. In fact, it was the onslaught of highly publicized breaches and identity theft scams that prompted the credit card companies to establish the PCI Data Security Standards in the first place, as a means to protect card members’ confidential information.


The original PCI documentation stated that “the most elusive vulnerabilities are those introduced through custom-developed e-commerce applications.” Gartner Inc. has estimated that 75 percent of online attacks target Web applications, specifically. As such, the new PCI mandate recognizes the critical importance of securing applications in an effort to maintain a vulnerability management program by offering more clarity around what is required for Web application security compliance.

It mandates that all web applications are protected against known attacks by applying either application code review or a web application firewall. To further clarify the requirements, the PCI security Standards Council issued an addendum in April of this year explaining what qualifies as a code review: 1) manual review of application source code; 2) proper use of automated application source code analyzer (scanning) tools; 3) manual Web application security vulnerability assessment; or 4) proper use of automated Web application security vulnerability assessment scanning tools.

Finding and mitigating vulnerabilities is the greater goal of PCI’s Web application security initiative, as it acknowledges what security professionals have known for a long time - security needs to be addressed from the very beginning. This is most adequately achieved through implementing both code review and a Web application firewall. Vulnerabilities must be identified early on, as it’s too late to address them once an application has been deployed.