Building a new snapshot fuzzer & fuzzing IDA

Introduction

It is January 2020 and it is this time of the year where I try to set goals for myself. I had just come back from spending Christmas with my family in France and felt fairly recharged. It always is an exciting time for me to think and plan …

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Reverse-engineering tcpip.sys: mechanics of a packet of the death (CVE-2021-24086)

Introduction

Since the beginning of my journey in computer security I have always been amazed and fascinated by true remote vulnerabilities. By true remotes, I mean bugs that are triggerable remotely without any user interaction. Not even a single click. As a result I am always on the lookout for …

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Modern attacks on the Chrome browser : optimizations and deoptimizations

Introduction

Late 2019, I presented at an internal Azimuth Security conference some work on hacking Chrome through it's JavaScript engine.

One of the topics I've been playing with at that time was deoptimization and so I discussed, among others, vulnerabilities in the deoptimizer. For my talk at InfiltrateCon 2020 in …

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A journey into IonMonkey: root-causing CVE-2019-9810.

A journey into IonMonkey: root-causing CVE-2019-9810.

Introduction

In May, I wanted to play with BigInt and evaluate how I could use them for browser exploitation. The exploit I wrote for the blazefox relied on a Javascript library developed by @5aelo that allows code to manipulate 64-bit integers. Around the same …

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Circumventing Chrome's hardening of typer bugs

Introduction

Some recent Chrome exploits were taking advantage of Bounds-Check-Elimination in order to get a R/W primitive from a TurboFan's typer bug (a bug that incorrectly computes type information during code optimization). Indeed during the simplified lowering phase when visiting a CheckBounds node if the engine can guarantee that …

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Introduction to TurboFan

Introduction

Ages ago I wrote a blog post here called first dip in the kernel pool, this year we're going to swim in a sea of nodes!

The current trend is to attack JavaScript engines and more specifically, optimizing JIT compilers such as V8's TurboFan, SpiderMonkey's IonMonkey, JavaScriptCore's Data …

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Introduction to SpiderMonkey exploitation.

Introduction

This blogpost covers the development of three exploits targeting SpiderMonkey JavaScript Shell interpreter and Mozilla Firefox on Windows 10 RS5 64-bit from the perspective of somebody that has never written a browser exploit nor looked closely at any JavaScript engine codebase.

As you have probably noticed, there has been …

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CVE-2017-2446 or JSC::JSGlobalObject::isHavingABadTime.

Introduction

This post will cover the development of an exploit for JavaScriptCore (JSC) from the perspective of someone with no background in browser exploitation.

Around the start of the year, I was pretty burnt out on CTF problems and was interested in writing an exploit for something more complicated and …

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Breaking ledgerctf's AES white-box challenge

Introduction

About a month ago, my mate b0n0n was working on the ledgerctf puzzles and challenged me to have a look at the ctf2 binary. I eventually did and this blogpost discusses the protection scheme and how I broke it. Before diving in though, here is a bit of background …

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beVX challenge on the operation table

Introduction

About two weeks ago, my friend mongo challenged me to solve a reverse-engineering puzzle put up by the SSD team for OffensiveCon2018 (which is a security conference that took place in Berlin in February). The challenge binary is available for download here and here is one of the original …

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