Serious Vulnerabilities Identified in Medtronic MyCareLink Smart Patient Readers

Three serious vulnerabilities have been identified in Medtronic MyCareLink (MCL) Smart Patient Readers, which could potentially be exploited to gain access to and modify patient data from the paired implanted cardiac device. Exploitation of the vulnerabilities together could permit remote code execution on the MCL Smart Patient Reader, allowing an attacker to take control of a paired cardiac device. In order to exploit the vulnerabilities, an attacker would need to be within Bluetooth signal proximity to the vulnerable product.

The flaws are present in all versions of the MCL Smart Model 25000 Patient Reader. The first vulnerability, tracked as CVE-2020-25183, is an authentication protocol vulnerability. The method used to authenticate the MCL Smart Patient Reader and the Medtronic MyCareLink Smart mobile app can be bypassed. An attacker using another mobile device or malicious app on the patient’s smartphone could authenticate to the patient’s MCL Smart Patient Reader, tricking it into believing it is communicating with the patient’s smartphone app. The vulnerability has been assigned a CVSS v3 base score of 8.0 out of 10.

A heap-based buffer overflow event can be triggered in the MCL Smart Patient Reader software stack by an authenticated attacker running a debug command. Once triggered, an attacker could then remotely execute code on the vulnerable MCL Smart Patient Reader, potentially allowing the attacker to take control of the device. The vulnerability is tracked as CVE-2020-27252 and has been assigned a CVSS v3 base score of 8.8 out of 10.

MCL Smart Patient Readers are also vulnerable to a race condition in the software update system, which could be exploited to upload and execute unsigned firmware on the Patient Reader. This vulnerability could also allow remote execution of arbitrary code on the MCL Smart Patient Reader and could give an attacker control of the device. The flaw is tracked as CVE-2020-27252 and has been assigned a CVSS v3 base score of 8.8 out of 10.

The vulnerabilities were identified by researchers at the Israeli firm Sternum, with UC Santa Barbara, University of Florida, and University of Michigan researchers independently identifying the improper authentication vulnerability.

The flaws were reported to Medtronic which has now released a firmware update to fix the vulnerabilities. The firmware update can be applied by updating the MyCareLink Smartapp via the associated mobile application store. Updating to mobile application version v5.2 will ensure the update is applied on the next use; however, in order for the patch to work, the user’s smartphone must be running iOS 10 or above or Android 6.0 or above.

Users have also been advised to maintain strong physical control over their home monitors and to restrict use of the home monitors to private environments. Patients should only use home monitors that have been obtained directly from their healthcare provider or a Medtronic representative.

Medtronic has also taken steps to improve security, including implementing Sternum’s enhanced integrity validation (EIV) technology which provides early detection and real-time mitigation of known vulnerability exploitation attempts, and Sternum’s advanced detection system technology, which enables device-level logging and monitoring of all device activity and behavior.

Author: Steve Alder has many years of experience as a journalist, and comes from a background in market research. He is a specialist on legal and regulatory affairs, and has several years of experience writing about HIPAA. Steve holds a B.Sc. from the University of Liverpool.