Introduction

Spring Boot Actuator is a developer’s best friend. It provides powerful, production-ready features for monitoring and managing applications with minimal effort. Through a series of HTTP endpoints, developers can check application health, view metrics, understand configurations and much more. However, when misconfigured and exposed to the public internet, this helpful tool can turn into a critical security vulnerability, offering a backdoor for attackers.

In this article I explore the methods used by security researchers and attackers to discover, enumerate and exploit these exposed actuator endpoints.

Phase 1: Discovery: Finding Exposed Instances

My testing begins with large‑scale scanning and fingerprinting to locate Spring Boot instances and determine whether their Actuator management endpoints are exposed to the internet.

Using Search Engines like Shodan

Internet‑wide scanners such as Shodan accelerate reconnaissance. I often fingerprint…