Mastering SSRF Vulnerabilities: Step-by-Step Guide with PortSwigger LabsLab

What is SSRF?

Server-side request forgery is a web security vulnerability that allows an attacker to cause the server-side application to make requests to an unintended location.

In a typical SSRF attack, the attacker might cause the server to make a connection to internal-only services within the organization’s infrastructure. In other cases, they may be able to force the server to connect to arbitrary external systems. This could leak sensitive data, such as authorization credentials.

What is SSRF vulnerability?

Server-Side Request Forgery (SSRF) is a type of security vulnerability that occurs when an attacker can trick a server into making HTTP requests to an unintended location, such as internal services, external servers, or even localhost. This can lead to unauthorized access to sensitive information, unauthorized interactions with internal services, or further exploitation of vulnerabilities.

Lets take portswigger labs as a example for better understanding:

Lab url :- https://0ad500930436c5bb808c263500f400d0.web-security-academy.net/

Description:- Basic SSRF against the local server

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

To solve the lab, change the stock check URL to access the admin interface at http://localhost/admin and delete the user carlos.

Solve this lab:-

1. First see the website

2. I try to check this send request when I add in url /admin what they give result,
3. This give a result if u re logged in then u see the page

4. Visit a product, click “Check stock”.

5. Check history in Burp Suite, and send request it to Burp Repeater.

6. Then I change the stockapi and send the request then response comes to server is unauthorized error.

7. The I will change again stock api to given in lab http://localhost/admin

8. The response is show the administrator page u can can delete any user
9. delete?username=carlos add in url

10. And click on follow redirect

11. It show unauthorized but u go in browser u solve this lab successfully.

It simple to solve u all lab to master the path traversal technique.