Best Ways to Find XSS in Web App Penetration Testing

Uncovering Cross-Site Scripting Vulnerabilities for Robust Security | Karthikeyan Nagaraj

Understanding Cross-Site Scripting (XSS)

What is XSS, and Why is it Dangerous?

Cross-Site Scripting, commonly referred to as XSS, is a type of security vulnerability that allows an attacker to inject malicious scripts into web pages viewed by other users. This happens when an application doesn’t properly validate and sanitize user-generated content before rendering it in a web page. The injected script then executes in the context of the victim’s browser, leading to various attacks, including data theft, session hijacking, and defacement of web pages.

Common Types of XSS

1. Stored XSS
Stored XSS occurs when the malicious script is permanently stored on the target server, often in a database or a file. When a user accesses the compromised page, the script is executed.

2. Reflected XSS
Reflected XSS involves the injection of a malicious script that is reflected off a web server. The script is embedded in a URL or a form input, and when a victim clicks on a malicious link or submits a form, the…