html-injection-testing

> AUTHORIZED USE ONLY: Use this skill only for authorized security assessments, defensive validation, or controlled educational environments. # HTML Injection Testing ## Purpose Identify and exploit HTML injection vulnerabilities that allow attackers to inject malicious HTML content into web applications. This vulnerability enables attackers to modify page appearance, create phishing pages, and steal user credentials through injected forms. ## Prerequisites ### Required Tools - Web browser with developer tools - Burp Suite or OWASP ZAP - Tamper Data or similar proxy - cURL for testing payloads ### Required Knowledge - HTML fundamentals - HTTP request/response structure - Web application input handling - Difference between HTML injection and XSS ## Outputs and Deliverables 1. **Vulnerability Report** - Identified injection points 2. **Exploitation Proof** - Demonstrated content manipulation 3. **Impact Assessment** - Potential phishing and defacement risks 4. **Remediation Guidance** - Input validation recommendations ## Core Workflow ### Phase 1: Understanding HTML Injection HTML injection occurs when user input is reflected in web pages without proper sanitization: ```html <!-- Vulnerable code example --> <div> Welcome, <?php echo $_GET['name']; ?> </div> <!-- Attack input --> ?name=<h1>Injected Content</h1> <!-- Rendered output --> <div> Welcome, <h1>Injected Content</h1> </div> ``` Key differences from XSS: - HTML injection: Only HTML tags are render...