RCE (Remote Code Execution): Exploitations and Security Tips

Exploiting a RCE vulnerability for a pentester is something of a Holy Grail. Depending on the context, there are numerous techniques for executing code remotely and thus exploit a RCE.

Beyond the principle of this type of vulnerability, we present in this article examples of RCE attacks and exploitations, as well as best practices and measures to implement to protect yourself.

Understanding and Preventing CORS Misconfiguration

Before presenting practical examples of CORS misconfiguration, it is important to define several points. First, the principle of the Same-Origin Policy (SOP) will be explained, since the CORS mechanism modifies these rules by making them more flexible. We will then explain how CORS work. Finally, we will look at practical examples of improper configuration.

Most applications have a critical feature for identifying users. The aim is to guarantee the confidentiality and integrity of their data. Common methods used to enable the server to identify a user include session cookies, JSON Web Tokens (JWT) or, in some cases, customised solutions.

Clearly, the logic behind the generation of these session tokens is essential, because bypassing or hijacking them can lead to account takeover, with critical impacts on data security and even the total compromise of the system.

What is a Mass Assignment vulnerability?

To make things easier for developers, many frameworks include features that automatically associate the parameters of an HTTP request with variables linked to an object in the application code.

A Mass Assignment vulnerability occurs when the server does not correctly filter the data transmitted by the user and associates it directly with an object without verification.

White box audit of a CI/CD pipeline on AWS

Recently, one of our clients asked us to review their Continuous Integration and Continuous Deployment (CI/CD) pipeline, deployed on an AWS infrastructure.

In this article, we will show how a developer with limited access to GitLab could have escalated his privileges and gained access to sensitive information to take control of the AWS infrastructure and cause significant damage to the organisation. We will also detail good practices and measures to implement to counter this type of risk.

What is Session Hijacking? Types of attacks and exploitations

Access control is a central element in ensuring the security of web applications. It must be based on robust authentication and session management that takes into account various security risks, such as session hijacking.

XSS exploitation, session fixation, lack of encryption, MFA bypass, etc., there are many techniques to hijack a user’s session. In this article, we present the main attacks and exploits.