Complete website security hardening guide: XSS, CSRF, SQL injection prevention

Website security is not optional. According to Verizon's data breach report, 43% of cyber attacks target small websites.

1. XSS (Cross-Site Scripting)

Attackers inject malicious scripts into web pages that execute in users' browsers.

Protection:

  1. Output encoding — escape all user-supplied data before rendering
  2. Content Security Policy (CSP) — restrict resource sources
  3. HttpOnly cookies — prevent script access to session cookies

2. CSRF (Cross-Site Request Forgery)

Attackers trick logged-in users into executing unintended actions.

Protection:

  1. CSRF tokens — include unique tokens in forms and validate server-side
  2. SameSite cookie attribute — set to Strict or Lax
  3. Validate Referer/Origin headers

3. SQL Injection

Attackers manipulate database queries through malicious input.

Protection:

  1. Parameterized queries (prepared statements) — ALWAYS use these
  2. ORM frameworks (Prisma, TypeORM, Eloquent)
  3. Principle of least privilege — never use root for app connections

4. More security practices

  • Password hashing with bcrypt/argon2
  • HTTPS enforcement with HSTS
  • Secure file upload handling (whitelist types, limit size, scan for malware)
  • Regular dependency updates

Security checklist

  • All user input validated and escaped
  • Parameterized queries or ORM in use
  • HTTPS enabled with HSTS
  • Security headers configured (CSP, X-Frame-Options)
  • CSRF protection or SameSite cookies
  • Passwords hashed with bcrypt/argon2
  • Correct file and directory permissions
  • Regular software/dependency updates
  • Logging and monitoring enabled
  • Data backup strategy established

16IDC Takeaway

Website security relies on defense in depth, not a single measure. Even with WAF and CDN, secure application-level coding remains an irreplaceable foundation.

Check our SSL/TLS deployment guide for infrastructure security.