TryHackMe Web Frameworks: Java | Full Walkthrough 2026

Review Spring Boot source, find the framework-specific sinks, and exploit each on the lab machine. 🐣 Room Link: https://tryhackme.com/room/webframewo... 🐱 Learning Objectives 🐱 🐴 Read Spring Boot source to locate framework-specific sinks 🐴 Recognise an exposed Actuator surface and lift secrets from /actuator/env and /actuator/heapdump 🐴 Spot a SQL injection that survives Spring's data layer through string-built raw SQL 🐴 Identify and exploit mass assignment in a controller that binds a full entity 🐴 Recognise the Java deserialisation sinks and drive one to remote code execution with ysoserial 🐱 Timestamps 🐱 [00:01:34] Task 2: Actuator Misconfiguration and the Environment Leak [00:09:14] Task 3: SQL Injection Below the Spring Data Layer [00:16:26] Task 4: Mass Assignment and Model Binding [00:23:10] Task 5: Java Deserialisation to RCE [00:32:01] Task 6: Practical, The White-Box Chain 🐱 Room Tasks 🐱 🪲 Task 1: Introduction 🪲 Task 2: Actuator Misconfiguration and the Environment Leak Reviewing application.properties, what single value assigned to management.endpoints.web.exposure.include opens the whole management surface rather than just health and info? The flag's key app.actuatorflag matches none of Actuator's masked words, so which endpoint renders it in cleartext when we read a named property? Read the property from the live app. What is the flag? 🪲 Task 3: SQL Injection Below the Spring Data Layer Spring's data layer parameterises by default, yet SearchController reintroduces injection by passing a string-built query to which Spring class? Reading the Flag entity tells us the schema before we send a payload. Which column do we UNION out to recover the hidden flag? Inject through the search endpoint to read the hidden flag. What is it? 🪲 Task 4: Mass Assignment and Model Binding The profile form renders only email, but the binder matches every property by name. Which User field do we overpost to reach admin? The lighter of the two fixes restricts which fields the binder populates without introducing a separate DTO. Which annotation marks the method that holds that fix? Overpost the field and read the admin dashboard. What is the flag? 🪲 Task 5: Java Deserialisation to RCE Rebuilding an object graph from attacker bytes is what makes this RCE possible. Which ObjectInputStream method, the sink in ImportController, performs that reconstruction? The sink alone is not enough; the gadget chain needs a vulnerable library on the classpath. Which dependency in pom.xml supplies the gadget that turns readObject into code execution? Run the gadget chain and read the dropped flag. What is it? 🪲 Task 6: Practical, The White-Box Chain Of the four findings, the code-execution one outranks the rest because its blast radius reaches the host. Which endpoint provides that foothold? The version pinned in pom.xml decides which payload works before we send a byte. Which ysoserial gadget chain matches the commons-collections version on the classpath? Use the foothold to read the host-only flag. What is it? 🪲 Task 7: Conclusion ⚠️ Educational Purpose Only This content is for educational and authorized penetration testing purposes only. Always ensure you have permission before testing on any systems. Don't forget to 👍 LIKE and 🔔 SUBSCRIBE for more cybersecurity tutorials! #tryhackme