From Capture to Code: A Technical Deep Dive into OWASP Juice Shop Vulnerabilities + Video

Listen to this Post

🐢▶️ Listen🚀

Introduction:

Bug bounty competitions provide an unparalleled hands-on environment for security researchers to transition from theoretical knowledge to practical exploitation. The OWASP Juice Shop, an intentionally vulnerable web application, serves as a modern training ground where ethical hackers can safely probe for real-world vulnerabilities like SQL Injection, Cross-Site Scripting (XSS), Insecure Direct Object References (IDOR), and Broken Access Control. This article dissects the technical underpinnings of these common flaws, providing a step-by-step guide to discovering and mitigating them, just as participants in a recent competition at Mandsaur University experienced firsthand.

Learning Objectives & Secrets:

• Objective 1: Master SQL Injection for Authentication Bypass – Understand how unsanitized user input can manipulate backend SQL queries to grant unauthorized admin access. Secret Tip: Always test with simple payloads like `’ OR 1=1–` first; if successful, the application is critically vulnerable.
• Objective 2: Exploit IDOR via API Manipulation – Learn to identify and exploit insecure direct object references by tampering with predictable identifiers in API requests. Secret Tip: Use Burp Suite to intercept and modify sequential IDs (e.g., `/rest/basket/6` to /rest/basket/1) to access other users’ private data.
• Objective 3: Execute DOM-Based XSS Attacks – Discover how client-side JavaScript can inadvertently execute malicious scripts from URL parameters. Secret Tip: The search bar is often a prime target; inject <iframe src="javascript:alert(xss)"> to trigger a proof-of-concept alert.

You Should Know:

1. Setting Up Your Lab Environment (Linux & Windows)
   Before hunting for bugs, you need a local instance of the Juice Shop. The fastest method is using Docker. This isolates the application and allows for safe, repeatable testing.

• Step 1 (Linux/macOS/Windows with Docker): Open your terminal or command prompt and pull the official image.

  docker pull bkimminich/juice-shop
  

• Step 2: Run the container, mapping port 3000 on your host to the container’s port.

  docker run -d -p 3000:3000 bkimminich/juice-shop
  

  For enhanced vulnerability coverage (including XXE challenges which are disabled by default in Docker), you can use the `unsafe` environment variable:

  docker run -d -p 3000:3000 -e "NODE_ENV=unsafe" bkimminich/juice-shop
  

• Step 3: Open your browser and navigate to `http://localhost:3000`. You now have a fully functional, vulnerable web application ready for testing.
  

  2. SQL Injection: Dumping the User Database

  SQL Injection remains one of the most critical web vulnerabilities. In Juice Shop, the product search endpoint is susceptible to a UNION-based SQL injection attack.

  – Step 1: Navigate to the search bar on the main page.
  – Step 2: Intercept the search request using Burp Suite or simply paste the following encoded payload into the URL bar after `http://localhost:3000/`:

  /rest/products/search?q=qwert%27%29%29%20UNION%20SELECT%20id%2C%20email%2C%20password%2C%20%274%27%2C%20%275%27%2C%20%276%27%2C%20%277%27%2C%20%278%27%2C%20%279%27%20FROM%20Users--
  

• Step 3: The application will return a list of products, but injected into this list will be the id, email, and `password` hashes of all registered users.
• What this does: The payload breaks out of the original `SELECT` query and appends a `UNION SELECT` statement that extracts data from the `Users` table. The `–` comments out the rest of the original query to prevent syntax errors.

3. IDOR: Viewing Another User’s Shopping Basket

Insecure Direct Object Reference occurs when an application exposes internal objects (like database keys) without verifying user authorization.

• Step 1: Log in to the Juice Shop with any valid user account.
• Step 2: Add an item to your basket.
• Step 3: Open Burp Suite and ensure your browser’s traffic is being proxied through it.
• Step 4: In Burp, locate the `GET /rest/basket/6` request (the number ‘6’ is your basket ID).
• Step 5: Send this request to Burp Repeater. Change the basket ID from `6` to `1` and send the request.
• Step 6: Observe the `200 OK` response. The server returns the contents of the admin’s basket (User ID 1). You can enumerate all baskets by incrementing the ID.
• Remediation: Always enforce server-side authorization checks. The API must verify that the authenticated user owns the resource being accessed, not just that they have a valid session.

4. Broken Access Control: Admin Panel Exposure

Broken Access Control is ranked 1 in the OWASP Top 10 for good reason. Often, developers hide admin links but fail to protect the underlying API endpoints.

• Step 1: Log out of the Juice Shop. You don’t even need to be authenticated.
• Step 2: Manually navigate to `http://localhost:3000//administration`.
• Step 3: The administration panel loads, displaying a list of all registered users, customer feedback, and other sensitive data.
• What this demonstrates: The application relies on “security by obscurity.” The link isn’t in the navigation menu, but there is no server-side check to confirm the user has admin privileges. Anyone who knows or guesses the URL can access it.
• Advanced Exploit: An even more critical flaw allows unauthenticated users to create administrator accounts by sending a crafted POST request to `/api/Users` with a `”role”:”admin”` parameter.

5. Cross-Site Scripting (XSS): Stored and DOM-Based

XSS allows attackers to inject malicious scripts into web pages viewed by other users. Juice Shop contains multiple XSS vectors.

• DOM-Based XSS (Search Bar):
• Step 1: Go to the Juice Shop homepage.
• Step 2: In the search bar, enter the following payload: <iframe src="javascript:alert(xss)">.
• Step 3: Press Enter. An alert box with “xss” will appear, confirming the vulnerability.

• Stored XSS (Customer Feedback):

• Step 1: Navigate to the “Customer Feedback” section.
• Step 2: In the comment field, paste a payload like <script>alert('Stored XSS')</script>.
• Step 3: Submit the feedback.
• Step 4: Go to the “About Us” page. The feedback slider will execute your script every time a user views the page.

6. XXE Injection: Reading Local Files

XML External Entity (XXE) injection is a powerful attack that can lead to local file disclosure and Server-Side Request Forgery (SSRF).

• Step 1: Navigate to the “Complaint” or file upload section.
• Step 2: Upload an XML file (or submit XML data) with the following payload:

  <!DOCTYPE foo [<!ENTITY xxe SYSTEM "file:///etc/passwd">]>
  <complaint><message>&xxe;</message></complaint>
  

• Step 3: If the application is vulnerable and the parser allows external entities, the contents of the `/etc/passwd` file will be returned in the response.

7. OSINT and Credential Discovery

Not all hacks are technical. Sometimes, the vulnerability lies in poor operational security.

• Challenge: Log in as the user [email protected].
• Method: The credentials for this account were publicly discoverable via a YouTube video with over 1.4 million views. This highlights the importance of not reusing credentials and being aware of your digital footprint.

What Undercode Say:

• Key Takeaway 1: Vulnerabilities are rarely obvious; they hide in the details of API requests, HTTP headers, and client-side JavaScript. Patience and methodical testing, such as checking every parameter in Burp Suite, are more valuable than speed.
• Key Takeaway 2: Ethical hacking is as much a mindset as it is a skillset. It requires thinking like an attacker—anticipating how a system can be misused—to build more resilient defenses. The “aha” moment comes not from breaking things, but from understanding the logic flaw that allowed the break.

Prediction:

• +1: The gamification of cybersecurity through platforms like OWASP Juice Shop and bug bounty competitions will continue to produce a new generation of highly skilled, practice-ready security professionals who understand the nuances of modern web and API security.
• +1: As API-driven architectures become the norm, the demand for hands-on training that specifically targets API security misconfigurations (BOLA, excessive data exposure) will surge, making tools like Juice Shop even more critical for developer and security training.
• -1: The ease with which these vulnerabilities can be exploited in a controlled environment often leads to a false sense of security. Many production applications still suffer from these same basic flaws, and the gap between training and real-world security remains a significant risk.

▶️ Related Video (82% Match):

🎯Let’s Practice For Free:

🎓 Live Courses & Certifications:

Join Undercode Academy for Verified Certifications

🚀 Request a Custom Project:

Secure, high-velocity infrastructure and disruptive technological engineering. Contact our engineering team for high-tier development and proprietary systems:
[email protected]
💎 Smart Architecture | 🛡️ Secure by Design | ⭐ Trusted by Thousands

IT/Security Reporter URL:

Reported By: https://lnkd.in/p/epR4YTE6 – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅

🔐JOIN OUR CYBER WORLD [ CVE News • HackMonitor • UndercodeNews ]

💬 Whatsapp | 💬 Telegram

📢 Follow UndercodeTesting & Stay Tuned:

𝕏 formerly Twitter 🐦 | @ Threads | 🔗 Linkedin | 🦋BlueSky