Building Secure Web Applications: Complete Guide

Web Security Essentials

Protect your applications from common vulnerabilities.

XSS (Cross-Site Scripting)

Attackers inject malicious scripts into your pages.

Prevention

• Escape user input before rendering
• Use Content Security Policy headers
• React escapes by default - avoid dangerouslySetInnerHTML

CSRF (Cross-Site Request Forgery)

Attackers trick users into performing unwanted actions.

Prevention

• Use CSRF tokens in forms
• SameSite cookie attribute
• Verify Origin/Referer headers

SQL Injection

Attackers manipulate database queries.

Prevention

• Use parameterized queries
• Never concatenate user input into SQL
• Use ORMs like Prisma, Django ORM

Authentication Best Practices

• Hash passwords with bcrypt
• Use HTTPS everywhere
• Implement rate limiting
• Use secure session management
• Enable 2FA for sensitive accounts

Security Headers

X-Content-Type-Options: nosniff
X-Frame-Options: DENY
X-XSS-Protection: 1; mode=block
Content-Security-Policy: default-src 'self'

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