Penetrating the Reality Wall: Long-Range and Through-Wall AR/VR Privacy Eavesdropping via Wireless Power Side Channel

Over the past decade, Metaverse technology (AR/VR) has seen widespread adoption in numerous areas, including gaming, social networking, and online collaboration. Although recent studies have exposed vulnerabilities in VR systems, they often apply methods (e.g., pre-installed malicious apps or scripts) from conventional mobile platforms directly, demonstrating impractical attacks that fail to investigate unique privacy leakages specific to VR platforms. In this paper, we present an orthogonal attempt to analyze the attack surface of the power side channel on AR/VR's network connection by capturing the through-wall wireless power in the network transmission medium (e.g., Wi-Fi signals) non-intrusively in a comparatively long distance (e.g., 5.0m-8.0m) and further reconstructing multi-level privacy-aware user behaviors. We propose MetaSpy to validate the feasibility and practicality of our disclosed wireless power-based traffic analysis attack. It first captures through-wall wireless power transmitted from the Wi-Fi router of an adjacent room, identifies the device type, then infers (i) user interactions such as browsing websites, running AR/VR apps, and performing various in-app activities, (ii) unseen VR-specific activities in VR games (e.g., Population: ONE), and (iii) avatar-based user re-identification and virtual keystroke inference corresponding to head movements. We evaluated the effectiveness of MetaSpy in four commercial-off-the-shelf (COTS) VR headsets, and the empirical results demonstrate its competitive accuracy in unveiling multi-level user privacy within virtual scenes in through-wall settings at a longer distance (1.8x-80x) than most of the recent studies, and it shows resilience to a series of external interference and impact factors. In addition, we also propose and evaluate effective countermeasures to protect data confidentiality in AR/VR wireless transmission.