Publications

Traces of Windows remote command execution

Tue, 09/13/2022 - 15:34
CSIRT
Pentest
A real ninja leaves no traces. However, in the Windows context, a lot of information are disseminated when performing actions and can be leveraged by DFIR analysts. Focusing on remote command execution techniques used by attackers and red-teamers, this article aims to get a collection of artifacts that can collected by analysts.

Exploiting CVE-2022-24816: A code injection in the jt-jiffle extension of GeoServer

Fri, 08/12/2022 - 17:49
Pentest
During one of our assessments we came across a server running GeoServer version 2.17.2. This version is outdated and affected by multiple security vulnerabilities. Among those vulnerabilities, one looked more promising than the others: CVE-2022-24816. This vulnerability is a code injection flaw in jt-jiffle that leads to an unauthenticated remote code execution.

CVE-2022-31813: Forwarding addresses is hard

Tue, 07/26/2022 - 10:00
Exploit
Pentest
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!

CCleaner forensics

Mon, 06/20/2022 - 15:58
CSIRT
During a ransomware attack, right after the ransomware was launched, we noticed the use of CCleaner as an anti-forensic tool to cover the attacker’s action. The following article aims to explore some key features of this tool from a forensic perspective. We will see how to identify the items that have been deleted and how they could be recovered. We focused on the free desktop version v6.00.9727.

The printer goes brrrrr!!!

Wed, 05/25/2022 - 10:43
Exploit
Reverse-engineering
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.

The reverse-engineering team presentation

Wed, 04/13/2022 - 18:20
Reverse-engineering
A lot of candidates, or simply fellow reversers, ask us how our team usually works: what kind of technologies are we looking into? What kind of projects? Do we work solo? How do we handle remote? etc. The goal of this blogpost is to share what we can about our internals, so you don't have to reverse us.

elFinder: The story of a repwning

Wed, 03/30/2022 - 11:01
Exploit
Pentest
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

Fri, 03/25/2022 - 14:49
Exploit
Reverse-engineering
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.

Finding gadgets like it's 2022

Mon, 03/14/2022 - 14:30
Pentest
So you have found an application vulnerable to Log4Shell, but the bypass gadgets are not working, and you did not manage to use a gadget from Ysoserial? If you read our last articles on finding Java gadgets you might have found a new one with gadget inspector. But what if gadget inspector did not find a valid chain? You might stop and be desperate because, as we saw, manual gadget research is not an easy task! In this article we will present a new methodology and multiple CodeQL queries to find gadget chains in Java a...