Publications

EVM unravelled: recovering ABI from bytecode

10/10/2023 The year-over-year growth in the use of decentralized applications and smart contracts brings an increasing prominence of security audits in this domain. Such audits are vital in maintaining the robustness and trustworthiness of platforms built on blockchain technologies like the Ethereum Virtual Machine (EVM). In a full black-box assessment—a methodology where the auditor has no knowledge of the system's inner workings—smart contracts can often appear more opaque compared to traditional centralized applications. This article del...

Introducing ntdissector, a swiss army knife for your NTDS.dit files

22/09/2023 This article tells our journey inside the ESE database and the NTDS features that led us to produce the ntdissector tool, suitable for offensive and defensive actions.

Presentation of the Pentest Team

15/09/2023 Are you a potential applicant wishing to know more about Synacktiv's pentest team before actually applying? Or someone considering relying on Synacktiv to perform a security assessment and wondering whether we can handle your project? Or just someone curious and eager to know more? In any case, this blogpost will hopefully enlighten you about key aspects of what we do and how we work.

Finding a POP chain on a common Symfony bundle: part 1

12/09/2023 The Symfony doctrine/doctrine-bundle package is one of the most common bundles installed along Symfony applications. At the time we are releasing this blogpost, it has been downloaded 144 million times, making it an interesting target for unserialize exploitation. If you want to improve your knowledge about PHP unserialize exploitation and see why weak typed languages are considered less secure, this blogpost is for you. The first part of this article aims to show a full methodology of POP chain research, it details the full code ana...

Magento for Security Audit

06/09/2023 Magento, also known as Adobe Commerce since it was bought by Adobe in 2018, is a popular CMS for e-commerce web applications, powering 2.3% of them as of 2021 (according to Statista). This article provides an overview of its inner workings from a security point of view as well as some key points to keep in mind when auditing Magento-based applications.

Web Architect - An Introduction

06/09/2023 This article is the first of a series detailing various security aspects of the most common technologies one can encounter on the web, starting with CMSs. As of today, most of the Content Management Systems (CMS) market shares are detained by PHP based solutions (WordPress accounting for most of it, admittedly). Thus, they are really common to find during web pentest engagements. This article and the following ones will tell you everything you need to know to get started when facing one of them, by studying two of the most common ones...

GPOddity: exploiting Active Directory GPOs through NTLM relaying, and more!

04/09/2023 During the pentest of an Active Directory environment, we recently came across a situation in which we were able to relay the authentication data of a user having write permissions on a sensitive Group Policy Object (GPO). Due to the peculiarities of GPOs’ implementation in Active Directory, existing tools do not allow their exploitation in NTLM relaying contexts. We however devised a new versatile exploitation vector that can be implemented through relaying, as well as a tool automating the attack, GPOddity, available on Synacktiv...

Windows secrets extraction: a summary

20/04/2023 Post-exploitation in Windows environments often implies secrets collection. The collected secrets can be reused for lateral or vertical movement, making them high value assets. Most people already know the LSASS process, but other secrets such as LSA secrets and DPAPI ones could also allow privilege escalation or access to sensitive resources. This article will describe the different types of secrets that can be found within a Windows machine, and public tools that can be used to retrieve them.

PHP filter chains: file read from error-based oracle

21/03/2023 The possibilities allowed by filter chains will never stop amazing us. Last time we saw that using them in a PHP file inclusion function would lead to remote code execution. Since then, another way to abuse them was published at the end of the DownUnderCTF 2022! Let's see how PHP filters can also be used to read local files when their content is not printed, thanks to an error-based oracle.

CI/CD secrets extraction, tips and tricks

01/03/2023 This article aims at describing how to exfiltrate secrets that are supposed to be securely stored inside CI/CD systems. For that purpose, the examples of Azure DevOps and GitHub Actions will be detailed, and the tool we developed to automate extraction will be presented.