Burp Suite for Web Apps
1 Global Definition
Burp Suite is a powerful web vulnerability scanner and penetration testing platform used to assess the security of web applications. Developed by PortSwigger, it acts as a proxy between the tester’s browser and the target application, allowing real-time inspection, interception, and manipulation of HTTP/S traffic. Burp Suite is considered an industry standard for web app pentesting.
1.1 Key Features
Intercepting Proxy
Captures and modifies HTTP/S requests and responses in transit.
- Inspect hidden parameters
- Modify form data before submission
- Replay requests with altered payloads
Web Vulnerability Scanner
Automates scanning for common web flaws.
- Detects SQL Injection
- Detects XSS
- Finds misconfigurations and insecure cookies
Repeater & Intruder
Tools for manual and automated testing.
- Repeater: Resend and tweak requests manually
- Intruder: Automates brute force and fuzzing attacks
- Test authentication, input validation, rate limits
Extensibility
Integrates with custom scripts and plugins.
- BApp Store with dozens of community extensions
- Supports Python & Java APIs
- Can integrate into CI/CD pipelines
1.2 Core Modules in Detail
- Proxy: Central component for intercepting traffic between client and server.
- Spider: Crawls target sites to map structure and discover hidden endpoints.
- Scanner: (Pro version) Automatically detects OWASP Top 10 vulnerabilities.
- Intruder: Performs automated attacks like brute force, fuzzing, or parameter tampering.
- Repeater: Allows manual modification and replay of HTTP requests.
- Decoder: Encodes/decodes data (Base64, URL, HTML, etc.) for analysis.
- Comparer: Highlights differences between two HTTP responses for pattern detection.
- Extender: Adds community-developed or custom modules.
1.3 Workflow Example
A typical Burp Suite pentest flow looks like this:
- Configure your browser to use Burp’s proxy (127.0.0.1:8080 by default).
- Navigate to the target web app — Burp intercepts traffic.
- Send interesting requests to Repeater for manual testing.
- Run the Scanner (Pro) to identify vulnerabilities.
- Use Intruder for brute force or fuzzing payloads.
- Analyze cookies, headers, and tokens with Decoder.
- Export findings into a professional report.
1.4 Security Considerations
- Legal Boundaries: Intercepting and modifying traffic without permission is illegal.
- Ethical Testing: Always ensure written authorization before testing web apps.
- Privacy Risks: Burp can expose sensitive data such as session cookies and authentication tokens.
- Tool Detection: Some applications may detect and block Burp proxy activity.
1.5 Strengths vs Weaknesses
Strengths:
- Industry-standard for web application pentesting
- Extremely flexible (manual + automated testing)
- Large community with many extensions
Weaknesses:
- Free version lacks automation (Scanner only in Pro)
- Resource intensive on large-scale tests
- Steep learning curve for beginners
1.6 Why It Matters
Burp Suite is essential for web application penetration testers, bug bounty hunters, and red teamers. It provides visibility into hidden vulnerabilities that cannot be found by scanners alone. By using Burp Suite, organizations can proactively identify and patch weaknesses before attackers exploit them. It remains the most widely used toolkit for professional web security testing worldwide.