Panera Bread, the "fast casual" restaurant chain that is the remote office for countless knowledge workers, is the latest business to suffer a major breach to a customer database — and the latest company to offer lessons in how not to respond to information from security researchers and analysts.

KrebsOnSecurity reported yesterday on a programming error on Panera's website that left millions of customer records - names, email addreses, physical addresses, birthdays, and the last four digits of their credit cards - exposed in plain text, to a casual search. That's bad enough, but when the details of the error's history began to come out, things got worse.

Dylan Houlihan, a security researcher, notified Panera on August 2, 2017 that the information was accessible. Initially, Panera's IT team simply didn't believe him. After additional correspondence, the company's director of information technology told Houlihan that they had verified his findings and remediated the problem.

Unfortunately, when Houlihan contact KrebsOnSecurity on April 2, the information was still available in plain text. The researcher said he contacted KrebsOnSecurity because Panera was showing no interest in, or effort toward, remediation.

"The Panerabread.com leak is an inexcusable oversight that not only took far too long to fix, but should have never occurred in the first place," says Paul Bischoff, privacy advocate at Comparitech.com, pointing out that customers' names, email addresses, physical addresses, birthdays, and the last four digits of their credit cards were accessible for eight months.

After KrebsOnSecurity contacted Panera, the website was taken offline and the information was no longer freely available, though Hold Security pointed out that it was still available to anyone who logged into the site — potentially, logging in using credentials that were openly available for 8 months.

"This kind of programming mistake is much more common than you would think. We highly advise website owners to perform penetration testing of their websites to identify these types of vulnerabilities as early as possible," says Mounir Hahad, head of Juniper Threat Labs at Juniper Networks. "In the case of Panerabread.com, the site had an open API that anyone on the Internet could query and did not require any type of authentication."

Panera talked on camera to Fox Business almost immediately after the KrebsOnSecurity contact. In their on-camera interview, the company said that only about 10,000 records had been accessible, not the 7 million records claimed by Houlihan. Further research by Hold Security and reported by KrebsOnSecurity indicates that Panera may have been correct about the Houlihan number being off; Hold Security's estimate for affected accounts is approximately 37 million.

"Panera's handling of its leak was a disaster. From dismissing responsible disclosure from the security community, to ignoring the problem for eight months, to racing to downplay the scope and say it had been remediated, Panera should be ashamed at how poorly it handled this from end-to-end," said Ben Johnson, CTO and co-founder of Obsidian Security in statement. "It is better to fix the problem than to race to the media with news of a purported fix. If there's a silver lining here, it's that we can have a new example how not to respond to a security leak.”

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