About HTML Injection
HTML Injection vulnerabilities occur when an attacker can inject malicious HTML content that gets rendered by the browser. This happens when user input is directly inserted into HTML output without proper validation or encoding.
Common HTML Injection Attack Types
Basic HTML Injection: Simple HTML injection using basic tags and attributes
Filter Bypass: Bypassing security filters and WAFs
File Upload Injection: Exploiting HTML injection through file upload functionality
Advanced Techniques: Complex methods to bypass modern protections
XSS via HTML Injection: Achieving Cross-Site Scripting through HTML injection
Common Vulnerable Functions
PHP: echo, print, printf, sprintf, htmlspecialchars (missing)
Python: print(), str.format(), % formatting, f-strings
Node.js: res.send(), res.write(), template engines
Java: out.print(), response.getWriter().print()
C#: Response.Write(), string interpolation
Real-World Impact
Cross-Site Scripting (XSS) attacks
Defacement and content manipulation
Bypass authentication and authorization mechanisms
Data exfiltration and sensitive information disclosure
Session hijacking and account takeover
Compliance violations and security breaches