Christopher Lentzsch (Ruhr-Universität Bochum), Sheel Jayesh Shah (North Carolina State University), Benjamin Andow (Google), Martin Degeling (Ruhr-Universität Bochum), Anupam Das (North Carolina State University), William Enck (North Carolina State University)

Amazon's voice-based assistant, Alexa, enables users to directly interact with various web services through natural language dialogues. It provides developers with the option to create third-party applications (known as Skills) to run on top of Alexa. While such applications ease users' interaction with smart devices and bolster a number of additional services, they also raise security and privacy concerns due to the personal setting they operate in. This paper aims to perform a systematic analysis of the Alexa skill ecosystem. We perform the first large-scale analysis of Alexa skills, obtained from seven different skill stores totaling to 90,194 unique skills. Our analysis reveals several limitations that exist in the current skill vetting process. We show that not only can a malicious user publish a skill under any arbitrary developer/company name, but she can also make backend code changes after approval to coax users into revealing unwanted information. We, next, formalize the different skill-squatting techniques and evaluate the efficacy of such techniques. We find that while certain approaches are more favorable than others, there is no substantial abuse of skill squatting in the real world. Lastly, we study the prevalence of privacy policies across different categories of skill, and more importantly the policy content of skills that use the Alexa permission model to access sensitive user data. We find that around 23.3% of such skills do not fully disclose the data types associated with the permissions requested. We conclude by providing some suggestions for strengthening the overall ecosystem, and thereby enhance transparency for end-users.

View More Papers

User Expectations and Understanding of Encrypted DNS Settings

Alexandra Nisenoff, Nick Feamster, Madeleine A Hoofnagle†, Sydney Zink. (University of Chicago and †Northwestern)

Read More

More than a Fair Share: Network Data Remanence Attacks...

Leila Rashidi (University of Calgary), Daniel Kostecki (Northeastern University), Alexander James (University of Calgary), Anthony Peterson (Northeastern University), Majid Ghaderi (University of Calgary), Samuel Jero (MIT Lincoln Laboratory), Cristina Nita-Rotaru (Northeastern University), Hamed Okhravi (MIT Lincoln Laboratory), Reihaneh Safavi-Naini (University of Calgary)

Read More

Demo #2: Sequential Attacks on Kalman Filter-Based Forward Collision...

Yuzhe Ma, Jon Sharp, Ruizhe Wang, Earlence Fernandes, and Jerry Zhu (University of Wisconsin–Madison)

Read More

Towards Measuring Supply Chain Attacks on Package Managers for...

Ruian Duan (Georgia Institute of Technology), Omar Alrawi (Georgia Institute of Technology), Ranjita Pai Kasturi (Georgia Institute of Technology), Ryan Elder (Georgia Institute of Technology), Brendan Saltaformaggio (Georgia Institute of Technology), Wenke Lee (Georgia Institute of Technology)

Read More