Security Web Development

Web Security Best Practices

February 20, 2024 | 18 min read
Web Security Best Practices

Web Security Best Practices

76%
of applications have security vulnerabilities
$4.35M
average cost of a data breach

OWASP Top 10 Security Risks

Injection Attacks

SQL, NoSQL, OS, and LDAP injection flaws


// Vulnerable Code
$query = "SELECT * FROM users WHERE username = '$username'";

// Secure Code
$stmt = $pdo->prepare("SELECT * FROM users WHERE username = ?");
$stmt->execute([$username]);

Broken Authentication

Session management and authentication flaws

  • Implement MFA
  • Secure password storage
  • Session timeout

Cross-Site Scripting (XSS) Prevention


// Unsafe output
echo $userInput;

// Safe output
echo htmlspecialchars($userInput, ENT_QUOTES, 'UTF-8');

// Content Security Policy
header("Content-Security-Policy: default-src 'self';");

Essential Security Headers

X-Frame-Options

X-Frame-Options: SAMEORIGIN

Prevents clickjacking attacks

X-XSS-Protection

X-XSS-Protection: 1; mode=block

Enables browser's XSS filtering

Author

Milan Salvi

Machine Learning Engineer & Data Scientist