TY - CHAP A1 - Ising, Fabian A1 - Poddebniak, Damian A1 - Kappert, Tobias A1 - Saatjohann, Christoph A1 - Schinzel, Sebastian T1 - Content-Type: multipart/oracle -- Tapping into Format Oracles in Email End-to-End Encryption T2 - 32nd USENIX Security Symposium N2 - S/MIME and OpenPGP use cryptographic constructions repeatedly shown to be vulnerable to format oracle attacks in protocols like TLS, SSH, or IKE. However, format oracle attacks in the End-to-End Encryption (E2EE) email setting are considered impractical as victims would need to open many attacker-modified emails and communicate the decryption result to the attacker. But is this really the case? In this paper, we survey how an attacker may remotely learn the decryption state in email E2EE. We analyze the interplay of MIME and IMAP and describe side-channels emerging from network patterns that leak the decryption status in Mail User Agents (MUAs). Concretely, we introduce specific MIME trees that produce decryption-dependent net work patterns when opened in a victim’s email client. We survey 19 OpenPGP- and S/MIME-enabled email clients and four cryptographic libraries and uncover a side-channel leaking the decryption status of S/MIME messages in one client. Further, we discuss why the exploitation in the other clients is impractical and show that it is due to missing feature support and implementation quirks. These unintended defenses create an unfortunate conflict between usability and security. We present more rigid countermeasures for MUA developers and the standards to prevent exploitation. Y1 - 2023 UR - https://www.usenix.org/conference/usenixsecurity23 PB - USENIX Association ER - TY - JOUR A1 - Gierling, Markus A1 - Saatjohann, Christoph A1 - Dresen, Christian A1 - Köbe, Julia A1 - Rath, Benjamin A1 - Eckardt, Lars A1 - Schinzel, Sebastian T1 - Reviewing Cyber Security Research of Implantable Medical Rhythm Devices regarding Patients’ Risk JF - 86. Jahrestagung und Herztage 2020 der DGK N2 - Introduction: The recent publication of several critical cyber security issues in cardiac implantable devices and the resulting press coverage upsets affected users and their trust in medical device producers. Reviewing the published security vulnerabilities regarding networked medical devices, it raises the question, if the reporting media, the responsible security researchers, and the producers handle security vulnerabilities appropriately. Are the media reports of security vulnerabilities in medical devices meaningful in a way that patients can assess their respective risk for an attack via the security vulnerability? The collaboration between IT-security experts and clinicians aims at reviewing published security vulnerabilities of rhythm devices, and evaluate overall patients risks. Methodology: We performed a literature review on security vulnerabilities in implantable medical devices with a focus on cardiac devices. We analyzed (Fig. 1) the (1) requirements for an attacker and the (2) technical feasibility and clustered them in three different scenarios: The first scenario requires that the attacker physically approaches a victim with a programming device. The second scenario requires proximity to the victim, e.g., within a few meters. The third and strongest attacker scenario is a remote attack that doesn’t require any physical proximity to the victim. We then compare the attacker scenarios and (3) the overall patients’ risks with the press coverage (overhyped, adequate, underhyped). (4) The resulting overall patients’ risk was rated by clinicians (security vulnerability of patients’ data, dangerous programming possible). Results: Out of the three analyzed incidents, we found one to be underhyped, one to be overhyped, and one was appropriate compared to the medial coverage (Fig. 2). The most occurring technical issues were based on the absence of basic security primitives. The patient damage for all of the analyzed incidents was fatal in the worst-case scenario. Further, the patient damage and the overall patient risks are disjunct due to the missing capability of performing large scale attacks. Conclusion: The resulting overall patients’ risks may not adequately reflect the patient damage in the considered cases. Often, the overall patient risk is not as severe as the necessary attacker capabilities are high and it would require strongly motivated attackers to perform the attack. Therefore, most of the reviewed cases are considered with a smaller overall patient risk than implied by press reports. Reviewing the ongoing IT-Security trends regarding implantable medical devices shows an increasing focus on researching in the field of medical device security. Therefore, further findings in the near future are to be expected. To deal with this fact in a responsible way, proper proactive knowledge management is mandatory. We recommend medical staff to critically reflect reports in mass media due to possible sensationalism. Therefore, we propose a joint approach in combining the technical expertise of cyber security experts with clinical aspects of medical experts, to ensure a solid understanding of a newly published vulnerability. The combination of both communities promises to result in better predictions for patients’ risks from security vulnerabilities in implanted cardiac devices. KW - Cyber Security KW - Cardiac Implantable Devices Y1 - 2020 U6 - http://dx.doi.org/10.1007/s00392-020-01621-0 VL - Band 109, Supplement 1, April 2020 SP - 1 EP - 2 ER - TY - CHAP A1 - Willing, Markus A1 - Saatjohann, Christoph A1 - Rath, Benjamin A1 - Schinzel, Sebastian A1 - Eckardt, Lars A1 - Köbe, Julia T1 - Experiences with General Data Protection Regulations and Remote Monitoring of Implantable Rhythm Devices T2 - 87. Jahrestagung der Deutsche Gesellschaft für Kardiologie – Herz‑ und Kreislauforschung e.V Y1 - 2021 U6 - http://dx.doi.org/10.1007/s00392-021-01843-w PB - Springer-Verlag GmbH ER - TY - CHAP A1 - Saatjohann, Christoph A1 - Ising, Fabian A1 - Krings, Luise A1 - Schinzel, Sebastian T1 - STALK: security analysis of smartwatches for kids T2 - ARES 2020: The 15th International Conference on Availability, Reliability and Security / Editors: Melanie Volkamer, Christian Wressnegger N2 - Smart wearable devices become more and more prevalent in the age of the Internet of Things. While people wear them as fitness trackers or full-fledged smartphones, they also come in unique versions as smartwatches for children. These watches allow parents to track the location of their children in real-time and offer a communication channel between parent and child. In this paper, we analyzed six smartwatches for children and the corresponding backend platforms and applications for security and privacy concerns. We structure our analysis in distinct attacker scenarios and collect and describe related literature outside academic publications. Using a cellular network Man-in-the-Middle setup, reverse engineering, and dynamic analysis, we found several severe security issues, allowing for sensitive data disclosure, complete watch takeover, and illegal remote monitoring functionality. KW - Security KW - Privacy Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-123548 SN - 978-1-4503-8833-7 SP - 1 EP - 10 ER - TY - CHAP A1 - Puschner, Endres A1 - Saatjohann, Christoph A1 - Willing, Markus A1 - Dresen, Christian A1 - Köbe, Julia A1 - Rath, Benjamin A1 - Paar, Christof A1 - Eckardt, Lars A1 - Haverkamp, Uwe A1 - Schinzel, Sebastian T1 - Listen to Your Heart: Evaluation of the Cardiologic Ecosystem T2 - ARES 2021: The 16th International Conference on Availability, Reliability and Security N2 - Modern implantable cardiologic devices communicate via radio frequency techniques and nearby gateways to a backend server on the internet. Those implanted devices, gateways, and servers form an ecosystem of proprietary hardware and protocols that process sensitive medical data and is often vital for patients’ health. This paper analyzes the security of this Ecosystem, from technical gateway aspects, via the programmer, to configure the implanted device, up to the processing of personal medical data from large cardiological device producers. Based on a real-world attacker model, we evaluated different devices and found several severe vulnerabilities. Furthermore, we could purchase a fully functional programmer for implantable cardiological devices, allowing us to re-program such devices or even induce electric shocks on untampered implanted devices. Additionally, we sent several Art. 15 and Art. 20 GDPR inquiries to manufacturers of implantable cardiologic devices, revealing non-conforming processes and a lack of awareness about patients’ rights and companies’ obligations. This, and the fact that many vulnerabilities are still to be found after many vulnerability disclosures in recent years, present a worrying security state of the whole ecosystem. Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-139012 ER - TY - CHAP A1 - Ebbers, Simon A1 - Ising, Fabian A1 - Saatjohann, Christoph A1 - Schinzel, Sebastian T1 - Grand Theft App: Digital Forensics of Vehicle Assistant Apps T2 - ARES 2021: The 16th International Conference on Availability, Reliability and Security N2 - Due to the increasing connectivity of modern vehicles, collected data is no longer only stored in the vehicle itself but also transmitted to car manufacturers and vehicle assistant apps. This development opens up new possibilities for digital forensics in criminal investigations involving modern vehicles. This paper deals with the digital forensic analysis of vehicle assistant apps of eight car manufacturers. We reconstruct the driver’s activities based on the data stored on the smartphones and in the manufacturer’s backend. For this purpose, data of the Android and iOS apps of the car manufacturers Audi, BMW, Ford, Mercedes, Opel, Seat, Tesla, and Volkswagen were extracted from the smartphone and examined using digital forensic methods following forensics guidelines. Additionally, manufacturer data was retrieved using Subject Access Requests. Using the extensive data gathered, we reconstruct trips and refueling processes, determine parking positions and duration, and track the locking and unlocking of the vehicle. Our findings show that the digital forensic investigation of smartphone applications is a useful addition to vehicle forensics and should therefore be taken into account in the strategic preparation of future digital forensic investigations. Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-139031 ER - TY - CHAP A1 - Saatjohann, Christoph A1 - Ising, Fabian A1 - Gierlings, Matthias A1 - Noss, Dominik A1 - Schimmler, Sascha A1 - Klemm, Alexander A1 - Grundmann, Leif A1 - Frosch, Tilman A1 - Schinzel, Sebastian T1 - Sicherheit medizintechnischer Protokolle im Krankenhaus T2 - SICHERHEIT 2022. Hrsg. Christian Wressnegger, Delphine Reinhardt, Thomas Barber, Bernhard C. Witt, Daniel Arp, Zoltan Mann N2 - Medizinische Einrichtungen waren in den letzten Jahren immer wieder von Cyber-Angriffen betroffen. Auch wenn sich diese Angriffe derzeit auf die Office-IT-Infrastruktur der Einrichtungen konzentrieren, existiert mit medizinischen Systemen und Kommunikationsprotokollen eine weitere wenig beachtete Angriffsoberfläche. In diesem Beitrag analysieren wir die weit verbreiteten medizintechnischen Kommunikations-Protokolle DICOM und HL7 sowie Protokoll-Implementierungen auf ihre IT-Sicherheit. Dafür präsentieren wir die Ergebnisse der Sicherheitsanalyse der DICOM- und HL7-Standards, einen Fuzzer “MedFUZZ” für diese Protokolle sowie einen Schwachstellenscanner “MedVAS”, der Schwachstellen in medizintechnischen Produktivumgebungen auffinden kann. Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-150072 SN - 978-3-88579-717-3 SN - 1617-5468 PB - Gesellschaft für Informatik e.V. CY - Bonn ER - TY - CHAP A1 - Saatjohann, Christoph A1 - Ising, Fabian A1 - Schinzel, Sebastian T1 - KIM: Kaos In der Medizin T2 - Sicherheit, Schutz und Zuverlässigkeit: Konferenzband der 12. Jahrestagung des Fachbereichs Sicherheit der Gesellschaft für Informatik e.V. (GI) N2 - Die sichere E-Mail-Infrastruktur für Ärzt*innen, Apotheker*innen, Krankenversicherungen und Kliniken in Deutschland, KIM - Kommunikation im Gesundheitswesen - ist mit über 200 Millionen E-Mails in den vergangenen zwei Jahren eine der am meisten genutzten Anwendungen in der Telematikinfrastruktur. Mit dem Ausgeben von S/MIME-Zertifikaten für alle medizinische Beteiligten in Deutschland verspricht KIM sichere Ende-zu-Ende-Verschlüsselung von E-Mails zwischen Heilberufler*innen in ganz Deutschland. In diesem Paper analysieren wir die KIM-Spezifikation sowie eine beispielhafte KIM-Installation in einer deutschen Zahnarztpraxis. Wir zeigen, dass KIM kryptografisch ein sehr hohes Sicherheitslevel erfüllt, doch in der Verarbeitung der E-Mails bei den Clients eine schwerwiegende Sicherheitslücke besteht. Weiterhin zeigen wir zwei Sicherheitslücken in dem KIM-Verarbeitungsmodul eines großen deutschen Unternehmens für medizinische Software. Diese Defizite zeigen außerdem Mängel in dem verpflichtenden Zulassungsprozess der KIM-Komponenten auf. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-178072 ER -