XPorter: A Study of the Multi-Port Charger Security on Privacy Leakage and Voice Injection

Tao Ni; Yongliang Chen; Weitao Xu; Lei Xue; Qingchuan Zhao

doi:10.1145/3570361.3613293

XPorter: A Study of the Multi-Port Charger Security on Privacy Leakage and Voice Injection

Tao Ni, Yongliang Chen, Weitao Xu, Lei Xue, Qingchuan Zhao^*

^*Corresponding author for this work

Department of Computer Science

Research output: Chapters, Conference Papers, Creative and Literary Works › RGC 32 - Refereed conference paper (with host publication) › peer-review

12 Citations (Scopus)

Abstract

Multi-port chargers, capable of simultaneously charging multiple mobile devices such as smartphones, have gained immense popularity and sold millions of units in recent years. However, this charging-targeted feature could expose security and privacy risks by allowing one of the simultaneously charging devices to communicate with another one if wrongly designed and implemented because these devices are actually interconnected. Unfortunately, such risks have not been well studied, and we have identified a novel attack surface that exists in the circuit design of multi-port chargers, which allows an adversary to leverage one port to (i) eavesdrop on the activities of other devices being charged and (ii) inaudibly inject malicious audio commands if the charging device supports voice assistant and USB-C interface.

In this paper, we design and implement a novel framework, XPorter, to analyze and demonstrate the uncovered security and privacy threats in multi-port chargers. Specifically, it leverages the changes in the voltage signals on one neighbor port to monitor the voltage changes of the charging port induced by various user activities, including recognizing the running apps and uncovering keystrokes. In addition, XPorter can also achieve inaudible audio injection attacks from the neighbor port to the charging mobile device via the USB-C interface. We extensively evaluate the effectiveness of XPorter using five commodity multi-port chargers and five mobile devices. The evaluation results show its high effectiveness in recognizing the launching of 20 mobile apps (88.7%) and uncovering unlocking passcode (98.8%). Furthermore, XPorter achieves 100% success rates in inaudible audio injection attacks on three voice assistants. Moreover, our study also shows that XPorter is resilient to various impact factors and presents the potential of attacking multiple victims.

© 2023 Copyright held by the owner/author(s). Publication rights licensed to ACM.

Original language	English
Title of host publication	ACM MobiCom '23
Subtitle of host publication	Proceedings of the 29th Annual International Conference on Mobile Computing and Networking
Publisher	Association for Computing Machinery
Number of pages	15
ISBN (Print)	978-1-4503-9990-6
DOIs	https://doi.org/10.1145/3570361.3613293
Publication status	Online published - Oct 2023
Event	29th Annual International Conference on Mobile Computing and Networking, MobiCom 2023 - Riu Plaza España Hotel, Madrid, Spain Duration: 2 Oct 2023 → 6 Oct 2023 https://sigmobile.org/mobicom/2023/

Conference

Conference	29th Annual International Conference on Mobile Computing and Networking, MobiCom 2023
Abbreviated title	ACM MobiCom 2023
Place	Spain
City	Madrid
Period	2/10/23 → 6/10/23
Internet address	https://sigmobile.org/mobicom/2023/

Bibliographical note

Research Unit(s) information for this publication is provided by the author(s) concerned.

Funding

We sincerely thank our shepherd and all anonymous reviewers for their constructive feedback. This work was supported by CityU APRC grant 9610563, the Research Grants Council of Hong Kong (CityU 21219223, C1029-22G, CityU 21201420, CityU 11201422), CCF-NSFOCUS Kunpeng Fund, NSFC Young Scientists Fund (No. 62002306), and NSFC (No. 62101471), NSF of Shandong province (No. ZR2021LZH010), and Shenzhen Science and Technology Funding Fundamental Research Program (2021Szvup126).

Research Keywords

Multi-port charger
Privacy leakage
Voice injection
USB-C interface

RGC Funding Information

RGC-funded

Access Output

10.1145/3570361.3613293

Other Access Options

Check CityUHK Library

Permanent Link

Right click to copy link

1 Finished
3 Active

ECS: Contactless Side Channels on Mobile Wireless Charging: Exploration and Mitigation
ZHAO, Q. (Principal Investigator / Project Coordinator)
1/10/23 → …
Project: Research
CRF-Sub-pj: Enabling Metadata-private and Accountable Networks at Scale
JIA, X. (Principal Investigator / Project Coordinator)
1/06/23 → …
Project: Research
GRF: Pushing the Boundaries of Wearable Sensing: A Tale of Two Modalities
XU, W. (Principal Investigator / Project Coordinator) & Ma, D. (Co-Investigator)
1/01/23 → …
Project: Research

Cite this

@inproceedings{cfddeac9aba7409a86178eca2bd54994,

title = "XPorter: A Study of the Multi-Port Charger Security on Privacy Leakage and Voice Injection",

abstract = "Multi-port chargers, capable of simultaneously charging multiple mobile devices such as smartphones, have gained immense popularity and sold millions of units in recent years. However, this charging-targeted feature could expose security and privacy risks by allowing one of the simultaneously charging devices to communicate with another one if wrongly designed and implemented because these devices are actually interconnected. Unfortunately, such risks have not been well studied, and we have identified a novel attack surface that exists in the circuit design of multi-port chargers, which allows an adversary to leverage one port to (i) eavesdrop on the activities of other devices being charged and (ii) inaudibly inject malicious audio commands if the charging device supports voice assistant and USB-C interface.In this paper, we design and implement a novel framework, XPorter, to analyze and demonstrate the uncovered security and privacy threats in multi-port chargers. Specifically, it leverages the changes in the voltage signals on one neighbor port to monitor the voltage changes of the charging port induced by various user activities, including recognizing the running apps and uncovering keystrokes. In addition, XPorter can also achieve inaudible audio injection attacks from the neighbor port to the charging mobile device via the USB-C interface. We extensively evaluate the effectiveness of XPorter using five commodity multi-port chargers and five mobile devices. The evaluation results show its high effectiveness in recognizing the launching of 20 mobile apps (88.7%) and uncovering unlocking passcode (98.8%). Furthermore, XPorter achieves 100% success rates in inaudible audio injection attacks on three voice assistants. Moreover, our study also shows that XPorter is resilient to various impact factors and presents the potential of attacking multiple victims.{\textcopyright} 2023 Copyright held by the owner/author(s). Publication rights licensed to ACM.",

keywords = "Multi-port charger, Privacy leakage, Voice injection, USB-C interface",

author = "Tao Ni and Yongliang Chen and Weitao Xu and Lei Xue and Qingchuan Zhao",

note = "Research Unit(s) information for this publication is provided by the author(s) concerned.; 29th Annual International Conference on Mobile Computing and Networking, MobiCom 2023, ACM MobiCom 2023 ; Conference date: 02-10-2023 Through 06-10-2023",

year = "2023",

month = oct,

doi = "10.1145/3570361.3613293",

language = "English",

isbn = "978-1-4503-9990-6",

booktitle = "ACM MobiCom '23",

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}

Ni, T , Chen, Y , Xu, W, Xue, L & Zhao, Q 2023, XPorter: A Study of the Multi-Port Charger Security on Privacy Leakage and Voice Injection. in ACM MobiCom '23: Proceedings of the 29th Annual International Conference on Mobile Computing and Networking. Association for Computing Machinery, 29th Annual International Conference on Mobile Computing and Networking, MobiCom 2023, Madrid, Spain, 2/10/23. https://doi.org/10.1145/3570361.3613293

XPorter: A Study of the Multi-Port Charger Security on Privacy Leakage and Voice Injection. / Ni, Tao ; Chen, Yongliang ; Xu, Weitao et al.
ACM MobiCom '23: Proceedings of the 29th Annual International Conference on Mobile Computing and Networking. Association for Computing Machinery, 2023.

Research output: Chapters, Conference Papers, Creative and Literary Works › RGC 32 - Refereed conference paper (with host publication) › peer-review

TY - GEN

T1 - XPorter

T2 - 29th Annual International Conference on Mobile Computing and Networking, MobiCom 2023

AU - Ni, Tao

AU - Chen, Yongliang

AU - Xu, Weitao

AU - Xue, Lei

AU - Zhao, Qingchuan

N1 - Research Unit(s) information for this publication is provided by the author(s) concerned.

PY - 2023/10

Y1 - 2023/10

N2 - Multi-port chargers, capable of simultaneously charging multiple mobile devices such as smartphones, have gained immense popularity and sold millions of units in recent years. However, this charging-targeted feature could expose security and privacy risks by allowing one of the simultaneously charging devices to communicate with another one if wrongly designed and implemented because these devices are actually interconnected. Unfortunately, such risks have not been well studied, and we have identified a novel attack surface that exists in the circuit design of multi-port chargers, which allows an adversary to leverage one port to (i) eavesdrop on the activities of other devices being charged and (ii) inaudibly inject malicious audio commands if the charging device supports voice assistant and USB-C interface.In this paper, we design and implement a novel framework, XPorter, to analyze and demonstrate the uncovered security and privacy threats in multi-port chargers. Specifically, it leverages the changes in the voltage signals on one neighbor port to monitor the voltage changes of the charging port induced by various user activities, including recognizing the running apps and uncovering keystrokes. In addition, XPorter can also achieve inaudible audio injection attacks from the neighbor port to the charging mobile device via the USB-C interface. We extensively evaluate the effectiveness of XPorter using five commodity multi-port chargers and five mobile devices. The evaluation results show its high effectiveness in recognizing the launching of 20 mobile apps (88.7%) and uncovering unlocking passcode (98.8%). Furthermore, XPorter achieves 100% success rates in inaudible audio injection attacks on three voice assistants. Moreover, our study also shows that XPorter is resilient to various impact factors and presents the potential of attacking multiple victims.© 2023 Copyright held by the owner/author(s). Publication rights licensed to ACM.

AB - Multi-port chargers, capable of simultaneously charging multiple mobile devices such as smartphones, have gained immense popularity and sold millions of units in recent years. However, this charging-targeted feature could expose security and privacy risks by allowing one of the simultaneously charging devices to communicate with another one if wrongly designed and implemented because these devices are actually interconnected. Unfortunately, such risks have not been well studied, and we have identified a novel attack surface that exists in the circuit design of multi-port chargers, which allows an adversary to leverage one port to (i) eavesdrop on the activities of other devices being charged and (ii) inaudibly inject malicious audio commands if the charging device supports voice assistant and USB-C interface.In this paper, we design and implement a novel framework, XPorter, to analyze and demonstrate the uncovered security and privacy threats in multi-port chargers. Specifically, it leverages the changes in the voltage signals on one neighbor port to monitor the voltage changes of the charging port induced by various user activities, including recognizing the running apps and uncovering keystrokes. In addition, XPorter can also achieve inaudible audio injection attacks from the neighbor port to the charging mobile device via the USB-C interface. We extensively evaluate the effectiveness of XPorter using five commodity multi-port chargers and five mobile devices. The evaluation results show its high effectiveness in recognizing the launching of 20 mobile apps (88.7%) and uncovering unlocking passcode (98.8%). Furthermore, XPorter achieves 100% success rates in inaudible audio injection attacks on three voice assistants. Moreover, our study also shows that XPorter is resilient to various impact factors and presents the potential of attacking multiple victims.© 2023 Copyright held by the owner/author(s). Publication rights licensed to ACM.

KW - Multi-port charger

KW - Privacy leakage

KW - Voice injection

KW - USB-C interface

U2 - 10.1145/3570361.3613293

DO - 10.1145/3570361.3613293

M3 - RGC 32 - Refereed conference paper (with host publication)

SN - 978-1-4503-9990-6

BT - ACM MobiCom '23

PB - Association for Computing Machinery

Y2 - 2 October 2023 through 6 October 2023

ER -

XPorter: A Study of the Multi-Port Charger Security on Privacy Leakage and Voice Injection

Abstract

Conference

Bibliographical note

Funding

Research Keywords

RGC Funding Information

Access Output

Other Access Options

Permanent Link

Fingerprint

Projects

ECS: Contactless Side Channels on Mobile Wireless Charging: Exploration and Mitigation

CRF-Sub-pj: Enabling Metadata-private and Accountable Networks at Scale

GRF: Pushing the Boundaries of Wearable Sensing: A Tale of Two Modalities

Cite this