Episode 58: Youssef Sammouda - Client-Side & ATO War Stories
Critical Thinking - Bug Bounty Podcast15 Helmi 2024

Episode 58: Youssef Sammouda - Client-Side & ATO War Stories

Episode 58: In this episode of Critical Thinking - Bug Bounty Podcast we finally sit down with Youssef Samouda and grill him on his various techniques for finding and exploiting client-side bugs and postMessage vulnerabilities. He shares some crazy stories about race conditions, exploiting hash change events, and leveraging scroll to text fragments.

Follow us on twitter at: @ctbbpodcast

We're new to this podcasting thing, so feel free to send us any feedback here: info@criticalthinkingpodcast.io

Shoutout to YTCracker for the awesome intro music!

------ Links ------

Follow your hosts Rhynorater & Teknogeek on twitter:

https://twitter.com/0xteknogeek

https://twitter.com/rhynorater

------ Ways to Support CTBBPodcast ------

Sign up for Caido using the referral code CTBBPODCAST for a 10% discount.

Hop on the CTBB Discord at https://ctbb.show/discord!

We also do Discord subs at $25, $10, $5 - premium subscribers get access to private masterclasses, exploits, tools, scripts, un-redacted bug reports, etc.

Today’s Guest: https://twitter.com/samm0uda?lang=en

https://ysamm.com/

Resources:

Client-side race conditions with postMessage:

https://ysamm.com/?p=742

Transferable Objects

https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Transferable_objects

Every known way to get references to windows, in javascript:

https://bluepnume.medium.com/every-known-way-to-get-references-to-windows-in-javascript-223778bede2d

Youssef’s interview with BBRE

https://www.youtube.com/watch?v=MXH1HqTFNm0

Timestamps:

(00:00:00) Introduction

(00:04:27) Client-side race conditions with postMessage

(00:18:12) On Hash Change Events and Scroll To Text Fragments

(00:32:00) Finding, documenting, and reporting complex bugs

(00:37:32) PostMessage Methodology

(00:45:05) Youssef's Vuln Story

(00:53:42) Where and how to look for ATO vulns

(01:05:21) MessagePort

(01:14:37) Window frame relationships

(01:20:24) Recon and JS monitoring

(01:37:03) Client-side routing

(01:48:05) MITMProxy

Jaksot(161)

Episode 49: Getting Live Hacking Event Invites & Bug Bounty Collab with Nagli

Episode 49: Getting Live Hacking Event Invites & Bug Bounty Collab with Nagli

Episode 49: In this episode of Critical Thinking - Bug Bounty Podcast, Justin Gardner is once again joined by Nagli to discuss some of their recent hacking discoveries. They talk about finding and exp...

14 Joulu 202351min

Episode 48: MVH, DEFCON Black Badge, Googler - Sam Erb

Episode 48: MVH, DEFCON Black Badge, Googler - Sam Erb

Episode 48: In this episode, joined by the spectacular Sam Erb, Google Security Engineer and DEFCON Black Badge winner. We talk about the importance of understanding how systems work to find vulnerabi...

7 Joulu 20231h 36min

Episode 47: CSP Research, Iframe Hopping, and Client-side Shenanigans

Episode 47: CSP Research, Iframe Hopping, and Client-side Shenanigans

Episode 47: In this episode of Critical Thinking - Bug Bounty Podcast, the holidays are fast approaching, and Justin and Joel discuss some of the struggles of getting back into the hacking groove duri...

30 Marras 20231h 31min

Episode 46: The SAML Ramble

Episode 46: The SAML Ramble

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 inti...

23 Marras 202343min

Episode 45: The OG Bug Bounty King - Frans Rosen

Episode 45: The OG Bug Bounty King - Frans Rosen

Episode 45: In this episode of Critical Thinking - Bug Bounty Podcast, we're thrilled to welcome Frans Rosén, an OG bug bounty hunter and co-founder of Detectify. We kick off with Frans sharing his jo...

16 Marras 20232h 36min

Episode 44: URL Parsing & Auth Bypass Magic

Episode 44: URL Parsing & Auth Bypass Magic

Episode 44: In this episode of Critical Thinking - Bug Bounty Podcast, the topic is URL structure, and Justin and Joel break down the elements that make up a URL and some common tips and tricks surrou...

9 Marras 20231h 11min

Episode 43: Caido - The Up-And-Coming HTTP Proxy

Episode 43: Caido - The Up-And-Coming HTTP Proxy

Episode 43: In this episode of Critical Thinking - Bug Bounty Podcast, we're joined by Emile from Caido, who shares his journey into the bug bounty and ethical hacking world. We kick off with a hilari...

2 Marras 20231h

Episode 42: Renniepak Interview & Intigriti LHE Recap

Episode 42: Renniepak Interview & Intigriti LHE Recap

Episode 42: In this episode of Critical Thinking - Bug Bounty Podcast, we're live from a hacking event in Portugal, and joined by the extremely talented René de Sain! He helps us cover a host of topic...

26 Loka 202359min