This post is the second out of three blog posts summarizing my (Louis Jannett) research on the design, security, and privacy of real-world Single Sign-On (SSO) implementations. It is based on my master's thesis that I wrote between April and October 2020 at the Chair for Network and Data Security.
We structured this blog post series into three parts according to the research questions of my master's thesis: Single Sign-On Protocols in the Wild, PostMessage Security in Single Sign-On, and Privacy in Single Sign-On Protocols.
Introduction to XS-Leaks in Single Sign-On
XS-Leaks in Single Sign-On: Account Leakage Attack
- The victim visits an attacker-controlled website.
- The victim is signed-in on the IdP (i.e., in Google Chrome with its Google account).
- The IdP supports the standardized `prompt=none` parameter.