Below you will find pages that utilize the taxonomy term “Keycloak”
POST to XSS: Leveraging Pseudo Protocols to Gain JavaScript Evaluation in SSO Flows
In 2020, a blog post was published here about the real-world security implications of a vague specification of the Redirect URI within the OAuth 2.0 RFC1. At that time, I focussed on redirect-based flows. This post uncovers additional protocol-level issues that lead to security vulnerabilities in popular and well-audited SSO implementations such as Authentik (CVE-2024-21637), Keycloak (CVE-2023-6134), and FusionAuth. Notably, the vulnerabilities were identified in the context of the OAuth 2.0 Form Post Response Mode2 and the SAML POST-Binding3 and therefore are not limited to OAuth 2.0 and OpenID Connect, but also affect SAML-based SSO-Flows.
In this post, we will dive into specification inaccuracies regarding the use of dangerous pseudo-schemes (JavaScript-URIs) in combination with POST-based SSO flows such as the OAuth 2.0 Form Post Response Mode2 and the SAML POST-Bindings3, resulting in a protocol-level Cross-Site Scripting (XSS) vulnerability pattern.
Real-life OIDC Security (VII): Responsible Disclosure
This is the final post of a series on Single Sign-On and OpenID Connect 1.0 security. In this post, Responsible Disclosure processes with five vendors and maintainers of popular OpenID Connect implementations are outlined. We reported vulnerabilities and security issues in Amazon Cognito, Bitbucket Server, GitLab, Keycloak, and Salesforce.
Real-life OIDC Security (VI): Reusable state leads to DoS Amplification
This is the sixth post of a series on Single Sign-On and OpenID Connect 1.0 security. This post outlines how the missing requirement of the state
value within the OpenID Connect Core specification leads to real-life security issues. Namely, the Denial-of-Service Amplification attack is introduced with CVE-2020-14302 (Keycloak) as an example.
Real-life OIDC Security (V): Redirect URI
This is the fifth post of a series on Single Sign-On and OpenID Connect 1.0 security. This post outlines how the vague specification of the Redirect URI within the OpenID Connect Core specification leads to real-life security issues. Finally, we show a real-world example of such an issue with CVE-2020-10776 (Keycloak) as an example.
Real-life OIDC Security (IV): Server-Side-Request-Forgery
This is the fourth post of a series on Single Sign-On and OpenID Connect 1.0 security. In this post, SSRF vulnerabilities that were discovered in popular OIDC implementations (Keycloak (CVE-2020-10770) and Amazon Cognito) are explained in detail.