Each year, Rapid7 penetration testers complete hundreds of internally and externally based penetration testing service engagements. This post is part of an ongoing series featuring testimonials of what goes on beneath the hoodie. For more insights, check out our 2019 Under the Hoodie report.
I was testing wireless and internal network vulnerabilities in a system of eight hospitals, and the wireless network specifically seemed to be fairly locked down. They had employed EAP-TLS, which allows devices to connect to the corporate wireless network using strictly certificate-based authentication in common deployments. This high-security configuration is still fairly unusual to see implemented consistently, since not every wireless device is technically capable of complying with it. In other words, it’s common to see exceptions made to this authentication policy for certain devices.
However, a full day or two of testing went by before we determined the standard methods of exploitation were just not going to work, at least against the employee workstations that were nearby at the time. It looked like EAP-TLS really was pretty bulletproof on these sites. I went for a walk around the hospital halls to see what other types of wireless devices I could find. While walking past the entrance to the Intensive Care Unit (ICU) in a particular hospital, I saw MAC addresses matching that of pagers (presumably used by the nurses and doctors) connecting and interacting with the corporate WiFi. I put my laptop and antenna in my backpack after deploying an evil twin of the corporate wireless, and headed back to the entrance of the ICU. After loitering a discreet and unobtrusive distance from the ICU for 15 minutes or so, I returned to ..