Broken Access: On the Challenges of Screen Reader Assisted Two-Factor and Passwordless Authentication

TL;DR

This paper investigates the security and accessibility challenges of screen reader-assisted authentication methods for blind and visually impaired users, revealing significant weaknesses and proposing an evaluation framework to identify issues early.

Contribution

It introduces the AWARE framework for systematic assessment of screen reader-assisted authentication, highlighting vulnerabilities and guiding designers to improve accessibility and security.

Findings

All observed scenarios show weaknesses in authentication methods.

Accessibility issues caused by imprecise screen reader instructions lead to vulnerabilities.

The AWARE framework helps identify security and accessibility problems early.

Abstract

In today's technology-driven world, web services have opened up new opportunities for blind and visually impaired people to interact independently. Securing interactions with these services is crucial; however, currently deployed authentication mainly concentrate on sighted users, overlooking the needs of the blind and visually impaired community. In this paper, we address this gap by investigating the security and accessibility aspects of these authentication when adopted by blind and visually impaired users. We model web authentication for such users as screen reader assisted authentication and introduce an evaluation framework called AWARE. Using AWARE, we then systematically assessed popular PC and smartphone-based screen readers against different authentication methods, including variants of 2FA and passwordless schemes, to simulate real-world scenarios. We analyzed these screen reader assisted authentication interactions with authentication methods in three settings: using a terminal (PC) with screen readers, a combination of the terminal (PC) and smartphone with screen readers, and smartphones with integrated screen readers. The results of our study underscore weaknesses in all of our observed screen reader assisted scenarios for real-life authentication methods. These weaknesses, encompassing specific accessibility issues caused by imprecise screen reader instructions, highlight vulnerability concerning observed scenarios for both real-world and research literature based attacks, including phishing, concurrency, fatigue, cross-service, and shoulder surfing. Broadly, our AWARE framework can be used by designers as a precursor to user studies which are typically time-consuming and tedious to perform, independently allowing to unfold security and accessibility problems early which designers can address prior to full-fledged user testing of more isolated issues.