Understanding the SAML Authentication Flow and XSS Vulnerabilities

Episode 46: In this episode of Critical Thinking - Bug Bounty Podcast, Justin is deep diving the topic of SAML (Security Assertion Markup Language), and walks through what it is and why it can be intimidating, before going over some key attack vectors to look for. Then he closes out with a commentary on a sample payload, and some HackerOne reports.

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KazHACKstan

https://kazhackstan.com/en

Testing SAML security with DAST

https://agrrrdog.blogspot.com/2023/01/testing-saml-security-with-dast.html

How to break SAML if I have paws?

https://speakerdeck.com/greendog/how-to-break-saml-if-i-have-paws?slide=20

How to Hunt Bugs in SAML; a Methodology

https://epi052.gitlab.io/notes-to-self/blog/2019-03-16-how-to-test-saml-a-methodology-part-three/

SAML Raider

https://portswigger.net/bappstore/c61cfa893bb14db4b01775554f7b802e

External Entity Injection during XML signature verification

https://bugs.chromium.org/p/project-zero/issues/detail?id=2313

mTLS: When certificate authentication is done wrong

https://github.blog/2023-08-17-mtls-when-certificate-authentication-is-done-wrong/

HackerOne Uber Report

https://hackerone.com/reports/136169

Timestamps:

(00:00:00) Introduction

(00:05:25) Understanding SAML and its complexities

(00:08:30) SAML Attack Vectors

(00:14:15) XML Signature Wrapping

(00:19:50) Some SAML tests to try

(00:30:30) Sample Payload description

(00:34:10) Token Recipient confusion

(00:36:05) HackerOne Reports