Publications

Exploiting a remote heap overflow with a custom TCP stack

13/02/2023 In November 2021 our team took part in the ZDI Pwn2Own Austin 2021 competition [1] with multiple entries. One of them successfully compromised the Western Digital MyCloudHome connected hard drive via a 0-day in the Netatalk daemon. Our exploit was unusual because triggering the vulnerability required to mess with the remote TCP stack, so we wrote our own. This blog post will provide some technical details about it.

Escaping from bhyve

04/01/2023 Bhyve is a hypervisor for FreeBSD. This blogpost will describe how a limited OOB write vulnerability in an adapter emulator can be turned into code execution allowing to escape from the guest machine.

Cool vulns don't live long - Netgear and Pwn2Own

06/12/2022 Pwn2own is a competition where hackers try to execute arbitrary code on selected devices. This blogpost will describe two vulnerabilities found in the Netgear RAX30 router, and explain how both were patched the day before the event.

CVE-2022-31813: Forwarding addresses is hard

26/07/2022 A few weeks ago, version 2.4.54 of Apache HTTPD server was released. It includes a fix for CVE-2022-31813, a vulnerability we identified in mod_proxy that could affect unsuspecting applications served by an Apache reverse proxy. Let's see why it is rated as low in the software changelog and why it still matters. TL;DR: when in doubt, patch!

The printer goes brrrrr!!!

25/05/2022 Network printers have been featured for the first time at Pwn2Own competition in Austin 2021. Three popular LaserJet printers were included in the completion: HP, Lexmark and Canon. During the event, we (Synacktiv) managed to compromise all of them allowing us to win the whole competition. In this post, we will focus on how we achieved code execution on the Canon printer.

elFinder: The story of a repwning

30/03/2022 We recently identified a path traversal issue in the elFinder software. It is assigned CVE identifier CVE-2022-26960. While the vulnerability is pretty classical, the story of its discovery is not. Keep on reading for the details.

Pwn2Own Austin 2021 : Defeating the Netgear R6700v3

25/03/2022 Twice a year ZDI organizes a competition where the goal is to hack hardware and software. During November 2021, in Austin, hackers tried to exploit hardware devices such as printers, routers, phones, home automation devices, NAS and more. This blogpost describes how we successfully took over a Netgear router from the WAN interface.

Heap tricks never get old - Insomni'hack teaser 2022

08/02/2022 The Synacktiv team participated in the Insomni'hack teaser 2022 last week-end and placed 9th out of 280 teams. The onetestament challenge was pretty interesting and taught me a few tricks so I have decided to write a detailed solution. In this writeup, I have tried to illustrate the thought process behind solving this challenge, rather than just the usual solve.py (which you can still find at the end of the article). Expect to see some (old) heap tricks and enjoy the read!

How to exploit CVE-2021-40539 on ManageEngine ADSelfService Plus

04/11/2021 During a penetration test we encountered the ManageEngine ADSelfService Plus (ADSS) solution. ADSS offers multiple functionalities such as managing password policies for administrators or self password reset/account unlock for Active Directory users. We decided to dig into this solution. However, our research barely started that a wild exploitation on this solution was announced. In this article we will explore the details of several vulnerabilities that allow an unauthenticated attacker to execute arbitrary code on the ...

Car hijacking swapping a single bit

26/10/2021 Used to interact with various ECU (Electronic Control Unit) in a car, the UDS (Unified Diagnostic Services) service is widely deployed by car constructors. This generic high level protocol is used to extract ECUs state, configure them or even update their firmware. When the implementation lacks cryptography support inside an ECU, the security level can decrease dramatically. This short blog post presents an hardware attack leveraging all diagnostic functions to an unauthorized tester.