CVE-2025-55182 React Server Components: Emulation and Detection

Table of Contents

1. Challenge

   Emulate CVE-2025-55182 Exploitation

   In this objective, you will emulate the early stages of exploiting a vulnerable React Server Components application affected by CVE-2025-55182.

   You will perform basic reconnaissance, test whether the application follows a vulnerable execution path, and use a proof-of-concept script to demonstrate unauthenticated remote code execution. The goal is to understand how an exposed service can be identified and exploited using attacker-controlled requests.

2. Challenge

   Detect Evidence of Exploitation

   In this objective, you will analyze the evidence generated during exploitation of the vulnerable React Server Components application. You will review the network captures you collected and identify the specific HTTP requests that carried the crafted payloads. You will examine the server’s exported logs to see how the vulnerable endpoint processed those requests, and observe how attacker-controlled fields were treated during the Flight decoding process. You will also inspect the filesystem artefacts created during command execution to understand how attacker behavior appears on the host.

   By correlating network traffic, application logs, and filesystem changes, you will develop a defender’s view of how CVE-2025-55182 presents during real-world exploitation. These insights will help you recognize similar indicators of compromise in your own environment and build a clearer picture of how an attack unfolds across multiple layers.

3. Challenge

   Protect Against Exploitation

   In this objective, your objective is to understand what it means to fix or harden an application affected by CVE-2025-55182. While the most effective solution in a real environment is to apply the official patched versions of the react-server-dom-* packages, this objective focuses on the underlying mechanics of the vulnerability. By exploring simple manual fixes, you will see how untrusted action metadata flows through the server and why certain fields should never be treated as executable. You will examine how input validation, conservative defaults, and defensive coding patterns can break the exploitation path and reduce the attack surface long before the official patch is applied.

4. Challenge

   The Last Objective

   Welcome to the final objective! This is your last chance to experiment in the environment. Clicking End Lab will end this little world that flittered into existence just for you.