Testing for XSS Vulnerabilities with Burp Suite

When to Use

• During authorized web application penetration testing to find reflected, stored, and DOM-based XSS
• When validating XSS findings reported by automated vulnerability scanners
• For testing the effectiveness of Content Security Policy (CSP) and XSS filters
• When assessing client-side security of single-page applications (SPAs)
• During bug bounty programs targeting XSS vulnerabilities

Prerequisites

• Authorization: Written scope and rules of engagement for the target application
• Burp Suite Professional: Licensed version with active scanner capabilities
• Browser: Firefox or Chromium with Burp CA certificate installed
• FoxyProxy: Browser extension configured to route traffic through Burp proxy (127.0.0.1:8080)
• Target application: Authenticated access with valid test credentials
• XSS payloads list: Custom wordlist or Burp's built-in XSS payload set

Workflow

Step 1: Configure Burp Suite and Map the Application

Set up the proxy and crawl the application to discover all input vectors.

# Burp Suite Configuration
1. Proxy > Options > Proxy Listeners: 127.0.0.1:8080
2. Tar…