KILLED BY CODEMob Sec Mobile Security Conference 4/11/2010 Herzliya

Danny Lieberman – Software Associates.v6

Agenda

Mobile medical is hot Applications Threat scenarios A threat model framework for secure

code Summary

Mobile medical devices are hotMobile consumer electronics creates potential for life-saving applications that are cheaper and more accessible than any other alternative.

Social benefit comes at the price of cyber threats.

In this talk we present a systematic method of analysing cyber threats in mobile medical devices.

Applications

Threat scenarios

Countermeasures

MOBILE MEDICAL APPLICATIONS

Data trackingWho: Patients, care-givers, doctorsWhat: Data acquisitionWhy: Controlling symptoms of chronic illness requires tracking data over long periods of time.• Glucose• Heart rate• Blood pressure• Dosage (insulin, dopamine …)• ...Platforms : Smart-phones, data & location-based services.

Diabetes

Parkinson/MSAAlzheimer

Asthma

Life-sustainingWho: PatientsWhat: Implanted devices for cardiac pacing, defibrillation, drug delivery…Why: Sustain lifePlatforms : Embedded devices with mobile connectivity for remote monitoring & programming.

Chronic heart disease

Epilepsy

Diabetes

Depression“…the latest technology in a full complement of patient-focused CRM products”

THREAT SCENARIOS

Threat scenario templateAn attacker may exploit vulnerabilities to cause damage to assets.

Security countermeasures mitigate vulnerabilities and reduce risk.

Asset

Vulnerability

Attacker

Radio attack scenario

Patient with ICD

Clear text

protocol

Threat T1 – A malicious attacker may exploit a clear text protocol and instruct an ICD to deliver a shock that would cause sudden cardiac death.

Vulnerability V1 – Clear text communications protocol

Countermeasure C1 – Encrypt network link Countermeasure C2 – Validate messages using secure tokens.

Attacker

Implantable Cardioverter DefibrillatorsIn 2008, approximately 350,000 pacemakers and 140,000 ICDs were implanted in the US.

Forecasted to $48BN in 2014.

 

Proof of concept attack:• Reverse-engineered

commands• Intercepted vital signs, history• Reprogrammed therapy

settings• DoS to deplete battery• Directed the ICD to deliver

137V shocks that would induce ventricular fibrillation in a patient.

2008 ICD vulnerability study

Device defect attack scenario

Patient

LifeSoftwar

e defects

Device malfunctio

n

Threat T2 – An internal short circuit is undetected by the device control software and may be fatal.Vulnerability V2 – Software doesn’t monitor hardware malfunctions

Countermeasure C3 – Notify customer service when hardware issue identified.Countermeasure C4 – Implement fail-safe function

FDA device recallsThe FDA issued 23 recalls of defective devices in H1/2010.

All were “Class 1” :

“reasonable probability that use of these products will cause serious adverse health consequences or death.”

At least 6 recalls were probably caused by software defects.

Malicious code attack scenario

ePHI

Weak or well-known

passwords

Software defects

OS vulnerabiliti

es

Malware

Threat T3 – Malicious code may be used in order to exploit multiple vulnerabilities and obtain patient informationVulnerability V3 – USB, and/or Internet access enabled

Countermeasure C4 – Hardware toggle USBCountermeasure C5 – Network isolation

Countermeasure C6 – Software security assessment

Mobile clinical assistantsMobile imaging analysis devices used by hospital radiologists had unplanned Internet access. Over 300 devices infected by Conficker and taken out of service.

Regulatory requirements mandated that the impacted hospitals would have to wait 90 days before the systems could be modified to remove the infections and vulnerabilities.

Where is the FDA?Guidance documents from 2015 extend FDA regulatory oversight –

1. Mobile apps that are medical devices, draft 2/2015

2. Cyber security for networked devices, final 10/2014

However - If a device has FDA pre-market approval, consumers cannot sue the manufacturer for injuries and disability incurred because of the device.

“Riegel v. Medtronic “, 2008

A threat model security framework

Objectives

Assess product risk Understand what

threats count Prioritize

countermeasures. Drive profits

Premarket approval.Cyber security asset and threat framework.

Assess product risk

Understand what threats count

Prioritize countermeasuresProduct management has 1 dollar in their pocket:

Countermeasure C1 – Encrypt network link to ICD

Countermeasure C21 – Validate POST requests with secure tokens.

Countermeasure C3 – Wearable “cloaker” to ensure that only authorized programmers can interact with the device.

Drive profits

Transparency means more eyeballs can look at issues.

More eyeballs reduces cost.

More eyeballs means safer devices.

Safer devices means more revenue.

Medical device threat models are transparent.

Sources Riegel v. Medtronic, Inc.

http://www.law.cornell.edu/supct/html/06-179.ZS.html Pacemakers and implantable cardiac defibrillators: Software

radio attacks and zero-power defenses.Daniel Halperin et al. Proceedings of the 29th Annual IEEE Symposium on Security and Privacy, May 2008.http://www.secure-medicine.org/icd-study/icd-study.pdf

Software transparency in imbedded medical deviceshttp://www.softwarefreedom.org/resources/2010/transparent-medical-devices.html

Prof. Nir Giladi, Tel Aviv Souraski Hospital Neurology Department, personal communication on data tracking for MSA patients

Biotronik – cellular pacemaker, http://www.biotronik.com/en/us/19412