kSMBd: a quick overview

12 May, 2023 by Arnaud Gatignol, Quentin Minster, Florent Saudel, Guillaume Teissier
In this blogpost, we introduce the analysis of one SMB implementation: kSMBd. It will be followed up by a talk at OffensiveCon 2023 named “Abusing Linux in-kernel SMB server to gain kernel remote code execution”.

The Fuzzing Guide to the Galaxy: An Attempt with Android System Services

Although the Android base is open source, many different constructors customize it with their own UIs and APIs. All these additions represent an extra attack surface that can change from one phone model to another. We tried to automatically fuzz the closed-source system services powering these modifications, discovering CVE-2022-39907 and CVE-2022-39908 along the way.

Fuzzing RDPEGFX with "what the fuzz"

14 Oct, 2022 by Colas Le Guernic, Jérémy Rubert, and Anonymous from Thalium team
Microsoft’s Remote Desktop Protocol (RDP) client was fuzzed by various teams in the past few years, it thus seemed like a good target to try a recent snapshot fuzzer: what the fuzz (wtf) (of which we are only users). In this companion post to our Hexacon 2022 talk (slides, video) we’ll show how we took advantage of wtf flexibility in order to efficiently fuzz the RDPEGFX channel of Microsoft RDP client and uncover CVE-2022-30221.

ECW 2021 - WriteUp

For the European Cyber Week CTF 2021 Thalium created some challenges in our core competencies: reverse and exploitation. This blog post presents some of the write-ups:

Thalium’s challenges have been less resolved than others. They were not that difficult, but probably a bit more unexpected. A few additional challenges designed by Thalium are:

NT objects access tracing

7 Jun, 2021 by Arnaud Gatignol
Draw me a map As homework during the lockdown, I wanted to automate the attack surface analysis of a target on Windows. The main objective was to construct a view of a software architecture to highlight the attack surface (whether remote or local). The software architecture can be composed of several elements: processes privileges ipc etc Usually, software architecture analysis is done with tools that give a view at a specific time (ProcessHacker, WinObjEx, etc).

SSTIC : how to setup a ctf win10 pwn user environment

2 Jun, 2021 by Thalium
Introduction This post aims to present how to easily setup a lightweight secure user pwning environment for Windows. From your binary challenge communicating with stdin/stdout, this environment provides a multi-client broker listening on a socket, redirecting it to the IO of your binary, and executing it in a jail. This environment is mainly based on the project AppJaillauncher-rs from trailofbits, with some security fixes and some tips to easily setup the RW rights to the system files from the jail.