Using Postman to Explore and Exploit Juice Shop Vulnerabilities May 9th, 2025
During my OWASP Juice Shop project, I spent a lot of time testing for vulnerabilities, and Postman became one of the most useful tools I worked with. As I’m building my skills in web application security, Postman helped me understand how client-server communication works and how I could use that to identify and exploit potential weaknesses.
What is Postman?
Postman is a platform for testing APIs. It lets me send requests and inspect responses in a clean, easy-to-use interface. Instead of working through a browser or command line, I was able to customize HTTP requests, set headers, cookies, and payloads, and then view the exact response coming back from the server. This was especially helpful when working on vulnerable applications like Juice Shop.
How I Used Postman for OWASP Juice Shop
In Juice Shop, I was testing several types of vulnerabilities, including SQL Injection, Cross-Site Scripting (XSS), and Authentication Failures. One of the most effective ways I used Postman was to test how the application handled user authentication and authorization.
For example, I used Postman to capture the login request and observed how JWT tokens were generated. After logging in as a standard user, I tried modifying the token and using it to access administrator-only endpoints. I also experimented with sending unauthorized PUT requests to change user profile data, and Postman made it easy to repeat these tests with small changes in payload or headers.
By adjusting parameters manually and observing how the server responded, I could better understand where the app was vulnerable and what could be done to patch it.
Why I Found Postman Useful in Security Testing
Postman gave me more control than browser-based testing. I could clearly see how the backend was responding to my inputs, and I didn’t have to rely on guessing. It also helped me document my process. I saved collections of requests and labeled them by vulnerability type, which helped me keep track of what I was testing and how.
It also allowed me to move at my own pace. If something failed, I could tweak one part at a time and figure out why. That kind of learning experience would have been harder to get using only automated scanners or browser tools.
Final Thoughts
Using Postman with Juice Shop helped me build confidence in both API testing and manual vulnerability analysis. It showed me how important it is to understand what’s happening behind the scenes and gave me hands-on practice with real-world concepts. As I continue working on web security projects, I know Postman will continue to be part of my toolkit.