HTML Encoding

WHAT IS HTML ENCODING?

HTML encoding is the process of converting special characters into a format that can be safely used within HTML markup. This is crucial for preventing errors and security vulnerabilities like Cross-Site Scripting (XSS).

HOW DOES HTML ENCODING WORK?

Replaces Special Characters – Converts <, >, &, ", and ' into entities like <, >, and & to prevent misinterpretation as code.

Uses Numeric Encoding – Characters can be represented as decimal (<) or hexadecimal (<) values.

Ensures Safe Display – Prevents HTML injection attacks (e.g., XSS) and ensures content appears correctly in browsers.

Common in Code & Data Storage – Used in web pages, databases, and URLs to safely handle special characters.

MITIGATION FOR HTML ENCODING?

Use Proper Encoding – Encode user input before displaying it (e.g., htmlspecialchars() in PHP).

Context-Aware Encoding – Encode differently for HTML, attributes, JavaScript, and URLs.

Use Security Libraries – Implement OWASP ESAPI or framework-specific escaping functions.

Sanitize User Input – Validate and strip harmful content before processing. 

CONCLUSION:

HTML encoding is essential for ensuring the correct display of special characters and preventing security risks like Cross-Site Scripting (XSS). By converting characters like <, >, and & into their safe equivalents, it helps maintain web page integrity and security. Proper implementation, including context-aware encoding, input sanitization, and security libraries, is key to protecting web applications from malicious attacks.