A software developer who found that Microsoft's ERP product Dynamics 365 for Finance and Operations exposed its private key to all and sundry was fobbed off by the company who initially told him that it was only accessible by someone who had obtained admin access.
At one stage in his dealings with Microsoft support, Matthias Gliwka says he asked for a phone number to contact the MSRC — the Microsoft Security Response Centre — but was instead given the number of Marine Spill Response Corporation which shares the same acronym!
This company has little to do with software; it is the largest, dedicated oil spill and emergency response organisation in the US.
Dynamics 365 for Finance and Operations is hosted on Microsoft's Azure cloud platform.
{loadposition sam08}As Gliwka described it a normal deployment has at least three systems: development, user acceptance testing (also referred to as “sandbox”) and production.
The user acceptance system is the same as the set-up of the production environment with one exception: while there’s no way to access the production servers besides through the web interface, the sandbox environment offers administrative access through the remote desktop protocol.
Gliwka says he had accessed a sandbox environment via RDP "to take a look and learn how Microsoft would set up a server hosting such a business critical application."
The hostname for a sandbox environment is customername.sandbox.operations.dynamics.com. A glance at the certificates inside the built-in “Certificate Manager” revealed the private key for the application.
Gliwka says he was shocked. "Sitting there in plain sight was a valid TLS certificate for the common name *.sandbox.operations.dynamics.com and the corresponding private key — by the courtesy of Microsoft IT SSL SHA2 CA!
"This certificate is shared across all sandbox environments, even those hosted for other Microsoft customers. It’s used to encrypt the Web traffic between the users of the software and the server. All you need to extract this certificate is access to ANY sandbox environment," he explained.
He contacted Microsoft and was initially told that it was not a serious issue as one needed admin access to extract the key. By the time he finally managed to get the company to see that this was not the case and the problem was fixed, 110 days had lapsed since his initial discovery.
After about seven weeks of trying to make contact, Gliwka says he debated whether to go public and post the details on the Web. But on second thoughts, he decided to contact freelance journalist Hanno Böck instead. Through this intermediary, a ticket was finally opened for the problem.
"Not even a week later a new case manager at MSRC finally replied to my ticket that all wildcard certificates associated with Dynamics 365 for Finance and Operations have been revoked and replaced with customer-environment-specific ones," Gliwka wrote.
Böck also wrote an article about the whole episode.