@inproceedings{EbbersIsingSaatjohannetal.2021,
  author    = {Ebbers, Simon and Ising, Fabian and Saatjohann, Christoph and Schinzel, Sebastian},
  title     = {Grand Theft App: Digital Forensics of Vehicle Assistant Apps},
  series = {ARES 2021: The 16th International Conference on Availability, Reliability and Security},
  booktitle = {ARES 2021: The 16th International Conference on Availability, Reliability and Security},
  doi       = {10.1145/3465481.3465754},
  url       = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-139031},
  year      = {2021},
  abstract  = {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.},
  language  = {en}
}
@inproceedings{PoddebniakIsingBoecketal.2021,
  author    = {Poddebniak, Damian and Ising, Fabian and B{\"o}ck, Hanno and Schinzel, Sebastian},
  title     = {Why TLS is better without STARTTLS: A Security Analysis of STARTTLS in the Email Context},
  series = {Proceedings of the 30th USENIX Security Symposium, August 11-13, 2021},
  volume    = {2021},
  booktitle = {Proceedings of the 30th USENIX Security Symposium, August 11-13, 2021},
  isbn      = {978-1-939133-24-3},
  year      = {2021},
  abstract  = {TLS is one of today's most widely used and best-analyzed encryption technologies. However, for historical reasons, TLS for email protocols is often not used directly but negotiated via STARTTLS. This additional negotiation adds complexity and was prone to security vulnerabilities such as naive STARTTLS stripping or command injection attacks in the past. We perform the first structured analysis of STARTTLS in SMTP, POP3, and IMAP and introduce EAST, a semi-automatic testing toolkit with more than 100 test cases covering a wide range of variants of STARTTLS stripping, command and response injections, tampering attacks, and UI spoofing attacks for email protocols. Our analysis focuses on the confidentiality and integrity of email submission (email client to SMTP server) and email retrieval (email client to POP3 or IMAP server). While some of our findings are also relevant for email transport (from one SMTP server to another), the security implications in email submission and retrieval are more critical because these connections involve not only individual email messages but also user credentials that allow access to a user's email archive. We used EAST to analyze 28 email clients and 23 servers. In total, we reported over 40 STARTTLS issues, some of which allow mailbox spoofing, credential stealing, and even the hosting of HTTPS with a cross-protocol attack on IMAP. We conducted an Internet-wide scan for the particularly dangerous command injection attack and found that 320.000 email servers (2\% of all email servers) are affected. Surprisingly, several clients were vulnerable to STARTTLS stripping attacks. In total, only 3 out of 28 clients did not show any STARTTLS-specific security issues. Even though the command injection attack received multiple CVEs in the past, EAST detected eight new instances of this problem. In total, only 7 out of 23 tested servers were never affected by this issue. We conclude that STARTTLS is error-prone to implement, under-specified in the standards, and should be avoided.},
  language  = {en}
}