Open access WiFi hotspots are widely deployed in many public places, including restaurants, parks, coffee shops, shopping malls, trains, airports, hotels, and libraries. While these hotspots provide an attractive option to stay connected, they may also track user activities and share user/device information with third-parties, through the use of trackers in their captive portal and landing websites. In this paper, we present a comprehensive privacy analysis of 67 unique public WiFi hotspots located in Montreal, Canada, and shed some light on the web tracking and data collection behaviors of these hotspots. Our study reveals the collection of a significant amount of privacy-sensitive personal data through the use of social login (e.g., Facebook and Google) and registration forms, and many instances of tracking activities, sometimes even before the user accepts the hotspot's privacy and terms of service policies. Most hotspots use persistent third-party tracking cookies within their captive portal site; these cookies can be used to follow the user's browsing behavior long after the user leaves the hotspots, e.g., up to 20 years. Additionally, several hotspots explicitly share (sometimes via HTTP) the collected personal and unique device information with many third-party tracking domains.
Apps on modern mobile operating systems can access various system resources with, or without, an explicit user permission. Although the OS generally maintains strict separation between apps, an app can still get access to another app’s private information, such as the user input, through numerous side-channels. For example, keystrokes and swipe gestures from a victim app can be inferred indirectly from the accelerometer or gyroscope output, allowing a zero-permission app to learn sensitive inputs such as passwords from the victim’s app. Current mobile OSes allow an app to defend itself in such situations only in some exceptional cases—e.g., by blocking screenshot captures in Android. In this article, we propose a general mechanism for apps to defend themselves from any unwanted implicit or explicit interference from other concurrently running apps. Our AppVeto solution enables an app developer to easily configure an app’s requirements for a safe environment; a foreground app can request the OS to disallow access—i.e., to enable veto powers—to selected side-channel-prone resources to all other running apps for a certain (short) duration, e.g., no access to the accelerometer during password input. In a sense, we enable a finer-grained access control policy than the current runtime permission model. We implement AppVeto on Android using the Xposed framework and Procedure Linkage Table hooking techniques, without changing Android APIs. Furthermore, we show that AppVeto imposes negligible overhead, while being effective against several well-known side-channel attacks—implemented via both Android Java and/or Native APIs.
No abstract
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.