This updated advisory is a follow-up to the original advisory titled ICSMA-17-009-01 St. Jude Merlin@home Transmitter Vulnerability that was published January 9, 2017, on the NCCIC/ICS-CERT web site.
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MedSec Holdings has identified a channel accessible by nonendpoint (“man-in-the-middle”) vulnerability in St. Jude Medical’s Merlin@home transmitter, which affects both the RF and inductive models. St. Jude Medical has validated the vulnerability and produced a new software version that mitigates this vulnerability. A third-party security research firm has verified that the new software version mitigates the identified vulnerability.
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This vulnerability could be exploited remotely. An attacker with high skill would be able to exploit this vulnerability.
The Food and Drug Administration (FDA) released a safety communication on January 9, 2017, Cybersecurity Vulnerabilities Identified in St. Jude Medical’s Implantable Cardiac Devices and Merlin@home Transmitter, to alert users about the identified vulnerability and corresponding mitigation as well as to provide recommendations to patients and healthcare providers. In response, ICS-CERT is releasing this advisory to provide additional information to patients and healthcare providers.
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The following Merlin@home transmitters are affected:
- Merlin@home, versions prior to Version 8.2.2:
- RF models: EX1150,
- Inductive models: EX1100, and
- Inductive models: EX1100 with MerlinOnDemand capability.
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Successful exploitation of this vulnerability may allow a remote attacker to access or influence communications between Merlin.net and transmitter endpoints.
ICS-CERT recommends that patients and healthcare providers evaluate the impact of this vulnerability based on their specific usage after reviewing the information referenced in this advisory and to contact the vendor for assistance with any questions or concerns related to this vulnerability.
St. Jude Medical is a US-based company headquartered in St. Paul, Minnesota.
The affected product, the Merlin@home transmitter, allows for remote care management of patients with implanted cardiac devices through scheduled transmissions, patient-initiated transmissions, and daily monitoring.
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According to St. Jude Medical, Merlin@home transmitter inductive models can have the MerlinOnDemand capability enabled. The MerlinOnDemand capability is a configuration that allows for multiple-patient use in healthcare facilities. The Merlin@home transmitter inductive models, with MerlinOnDemand capability enabled, is used by healthcare professionals to read patient Implantable Medical Devices (IMDs) data during office visits. Inductive Merlin@home transmitters with MerlinOnDemand capability enabled contain the same hardware and software as other inductive Merlin@home transmitters, but with slightly different capability, resulting from a different configuration on the server/Merlin.net side, which is controlled by St. Jude Medical. The Merlin@home transmitter inductive model with the MerlinOnDemand capability enabled is set up to pair with multiple IMDs, which differs from the Merlin@home transmitter that has not enabled this capability, as it is intended for home use. Also, the Merlin@home transmitter inductive model with MerlinOnDemand capability enabled does not use RF to communicate with IMDs. Instead, it uses close range impedance telemetry.
According to St. Jude Medical, the Merlin@home transmitter inductive models are deployed across the Healthcare and Public Health sector. St. Jude Medical estimates that Merlin@home transmitters inductive models, with MerlinOnDemand capability enabled, correspond to approximately 0.1 percent of the total Merlin@home transmitters available and that these products are used worldwide.
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CHANNEL ACCESSIBLE BY NONENDPOINT (“MAN-IN-THE-MIDDLE”)
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The identities of the endpoints for the communication channel between the transmitter and St. Jude Medical’s web site, Merlin.net, are not verified. This may allow a remote attacker to access or influence communications between the identified endpoints.
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CVE-2017-5149 has been assigned to this vulnerability. A CVSS v3 base score of 8.9 has been assigned; the CVSS vector string is (AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:H).
This vulnerability could be exploited remotely.
EXISTENCE OF EXPLOIT
No known public exploits specifically target this vulnerability.
An attacker with high skill would be able to exploit this vulnerability.
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St. Jude Medical has developed an updated software version for all Merlin@home transmitters, including inductive Merlin@home transmitters with the MerlinOnDemand capability, which mitigates the identified vulnerability and provides additional security enhancements.
The new version of the transmitter software, Version 8.2.2, will be automatically updated over a period of several months, when all models of the Merlin@home transmitters are connected to an Ethernet, WiFi, cellular network, or a landline. St. Jude Medical recommends that users keep Merlin@home transmitters powered and connected at all times to receive this update and future updates.
For additional information about the vulnerability or the software update process, users can review information from St. Jude Medical at:
Patients and healthcare providers with questions can call the Merlin hotline at
1-877-696-3754 or visit www.sjm.com/Merlin for more information.
The FDA issued a safety communication on January 9, 2017, Cybersecurity Vulnerabilities Identified in St. Jude Medical’s Implantable Cardiac Devices and Merlin@home Transmitter, which includes recommendations for patients and healthcare providers and is available at the following location:
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St. Jude Medical is continuing to work with ICS-CERT and the FDA to address additional security issues that have been identified. As additional information becomes available, ICS-CERT in coordination with the FDA, will release additional information products.
ICS-CERT reminds Internet users that directly connecting any device to the Internet without explicitly controlling communication with or access to the connected device, significantly increases the risk of a cybersecurity-related event.
ICS-CERT provides recommended security practices on the ICS-CERT web page at http://ics-cert.us-cert.gov/content/recommended-practices. ICS-CERT reminds members of the healthcare and public health sector to perform proper impact analysis and risk assessment prior to deploying defensive measures.
Additional mitigation guidance and recommended practices are publicly available in the ICS‑CERT Technical Information Paper, ICS-TIP-12-146-01B–Targeted Cyber Intrusion Detection and Mitigation Strategies, that is available for download from the ICS-CERT web site (http://ics-cert.us-cert.gov/).