Publications

Car hijacking swapping a single bit

26/10/2021
Hardware
Exploit
Pentest
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.

Your vulnerability is in another OEM!

02/09/2021
Exploit
Reverse-engineering
Among targets for the Pwn2own Tokyo 2020 was 2 NAS, the Synology DiskStation DS418play and Western Digital My Cloud Pro PR4100. We took a look at both, and quickly found out Western Digital PR4100 was vulnerable via its webserver. However, exploitation was not THAT easy (it was not that hard either) and ultimately it did not even mattered since the vulnerability was wiped by a major OS update pushed mere days before the contest. In the end, the vulnerable code we audited might not have even been written by Western D...

Exploitation of a double free vulnerability in Ubuntu shiftfs driver (CVE-2021-3492)

13/07/2021
Exploit
This year again, the international contest Pwn2Own Vancouver took place in the beginning of April. Among the different categories, two major operating systems were suggested for the Local Escalation of Privilege category (LPE): Linux (Ubuntu) and Windows 10. This article describes how a Ubuntu kernel vulnerability was found and exploited during this contest allowing to gain root access from an unprivileged user.

Playing with ImageTragick like it's 2016

28/05/2021
Exploit
Pentest
You probably already have encountered document converting features that deal with ImageMagick during engagements but for some reason you were not able to exploit them. This article will mention some techniques that could be used when an older version of ImageMagick is targeted. Spoiler alert: this is not new.

An Interesting Feature in the Samsung DSP Driver

02/03/2021
Exploit
In February 2021 Samsung made some changes in one of its low level drivers : the Digital Signal Processor (DSP) Linux driver. They removed one interesting feature : the ability for untrusted apps to load a custom DSP firmware of their choice. The driver is present on Galaxy S20 and Galaxy S21 Exynos based phones (and probably on Galaxy Note 20 too). This article presents how to use this feature to boot the DSP on a custom firmware, and how to use this custom firmware along with bugs in the DSP driver to gain ker...

Pwn2Own Tokyo 2020: Defeating the TP-Link AC1750

01/03/2021
Exploit
A team of Synacktiv security experts participated to the last edition of Pwn2Own by submitting a LAN-side exploit against the TP-Link AC1750. This blogpost aims to describe the process of discovery and exploitation of this vulnerability, including the presentation of exploitation code.