> For the complete documentation index, see [llms.txt](https://ganesha-hk.gitbook.io/cybersecurity-writeups/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ganesha-hk.gitbook.io/cybersecurity-writeups/port-swigger-ssrf-lab/lab-1.md).

# lab-1

## Basic SSRF Against the Local Server

**Difficulty:** Apprentice

### Lab Description

This lab has a stock check feature which fetches data from an internal system.

**Objective:** Change the stock check URL to access the admin interface at `http://localhost/admin` and delete the user `carlos`.

### Root Cause

Some application servers have permission to make requests to other internal application servers to retrieve data. Developers sometimes allow these servers to access sensitive panels — such as admin or IT support interfaces — without any authentication, on the assumption that they are not reachable from outside the network. However, if the application makes outbound requests using a user-supplied URL without validation, an attacker can point that URL at internal resources the server can reach but the attacker normally cannot.

### Exploitation

1. Access any product page and find the **stock check** functionality. Click it and capture the request in Burp.
2. Find the `POST /product/stock` endpoint and send it to Repeater.
3. Change the `stockApi` parameter value to `http://localhost/admin` and send the request.
4. Open the response in the browser — the admin panel is accessible.
5. Click **Delete carlos** and note the URL path: `/admin/delete?username=carlos`.
6. Back in Repeater, set the `stockApi` parameter to:

   ```
   http://localhost/admin/delete?username=carlos
   ```
7. Send the request — `carlos` is deleted and the lab is complete.

### Lesson Learned

* The server must never blindly trust user-supplied URLs.
* Admin panels and other sensitive internal interfaces must require authentication even for loopback and internal network requests — "not reachable from outside" is not a substitute for access control.


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