Summary
Access Control Vulnerabilities: Unprotected Admin Functionality with Unpredictable URL This lab is from PortSwigger Web Security Academy, a hands-on platform for learning and practicing web application security through realistic vulnerability labs. Introduction In this lab, I explored an access control vulnerability involving unprotected administrative functionality with an unpredictable URL. The application attempted to hide the administrator panel behind a randomly generated-looking URL. However, the endpoint did not enforce authentication, meaning that anyone who discovered the URL could access administrative functionality. Lab Walkthrough:
- Accessing the Lab I started by clicking the “Access the lab” button in PortSwigger’s Web Security Academy and launched the vulnerable application.
- Checking My Account:- I navigated to the My Account page. The application asked for an ID/username and password. Since I did not have valid credentials, I looked for another way to identify potentially exposed functionality.
- Inspecting the Source Code:- I inspected the application’s source code and searched for references to administrative functionality. During this process, I discovered a small JavaScript snippet containing an unusual endpoint: /admin-04j4yp The endpoint appeared to be intentionally unpredictable to make the admin panel harder to discover.
- Accessing the Hidden Admin Panel: I directly visited: /admin-04j4yp The application provided direct access to the administrator panel without requiring authentication. This confirmed that the unpredictable URL was being used as a form of security through obscurity rather than implementing proper access control.
- Identifying the Users The administrator panel displayed two user accounts. One of them was: carlos Since I had administrative functionality without authenticating, I was able to interact with the user-management functionality.
- Deleting the User I selected the carlos account and deleted it. The lab was then successfully completed. Vulnerability: The vulnerability exists because the application relies on an unpredictable URL to hide administrative functionality, rather than enforcing proper authentication and authorization. Get Vivek Yadav’s stories in your inbox Join Medium for free to get updates from this writer. Even though the URL: /admin-04j4yp is difficult to guess, it was exposed in the application’s client-side JavaScript. Once discovered, there was no authentication or authorization check preventing access to the administrative panel. Impact: An attacker who discovers the hidden endpoint could potentially:
- Access administrative functionality without authentication
- View sensitive administrative information
- Create or delete users
- Modify application data
- Change user privileges
- Perform other privileged administrative actions In this lab, the vulnerability allowed me to delete the carlos user account without having administrator credentials. Root Cause: The root cause was insufficient server-side access control. The application relied on an unpredictable URL as a security mechanism. However: An unpredictable URL is not a substitute for authentication and authorization. Client-side JavaScript is accessible to users and can be inspected to discover hidden endpoints. Remediation: To prevent this vulnerability, the application should:
- Require authentication before accessing administrative functionality.
- Implement server-side role-based authorization.
- Verify administrator privileges for every administrative action.
- Never rely on hidden or unpredictable URLs as a security mechanism.
- Protect administrative APIs as well as frontend pages.
- Return 401 Unauthorized or403 Forbidden for unauthorized requests. - Monitor and log attempts to access administrative endpoints. Key Takeaway: Even when an administrative URL is unpredictable, it can potentially be discovered through source code, JavaScript files, application behavior, or other information leaks. Every privileged endpoint must independently enforce server-side authentication and authorization. References
- Platform: PortSwigger Web Security Academy
- Topic: Access Control Vulnerabilities
- Vulnerability: Unprotected admin functionality with unpredictable URL
- OWASP: A01 — Broken Access Control
- CWE: CWE-284 — Improper Access Control GoodByeee….