OWASP Top 10 2024: What Changed and Fix These First

The OWASP Foundation released its 2024 update to the Top 10 vulnerabilities list, and the changes matter. If your team is still operating from the 2021 version, you're missing critical shifts in how attackers exploit modern applications. The gap between knowing the list and actually fixing vulnerabilities is where most organizations stumble.

This isn't a complete overhaul—the foundation remains solid. But the priorities have shifted, and two new threat categories now sit at the table. Here's what you need to know and where to start.

What Actually Changed

New Entries and Repositioning

The 2024 list introduces A05:2024 – Broken Access Control in a more prominent position, reflecting the real-world prevalence of privilege escalation and authorization bypass attacks. More significantly, AI security concerns now appear explicitly in the list, addressing machine learning model poisoning, prompt injection, and training data leakage—issues that barely existed in 2021.

A01:2024 – Broken Access Control remains the most prevalent issue. If you haven't audited your authentication and authorization logic recently, start there.

What Got Demoted or Renamed

Classic injection attacks (SQL, OS, LDAP) have been grouped more tightly under A03:2024 – Injection. Cross-site scripting (XSS) sits under A07:2024 – Cross-Site Scripting (XSS), largely because frameworks now handle much of the heavy lifting. The real vulnerability now is application-specific logic where developers bypass framework protections.

The Vulnerabilities Your Team Should Fix First

1. Broken Access Control (A05)

Access control failures are the most commonly exploited vulnerability type. The fix isn't complicated—it requires discipline.

typescriptCopy
// Bad: Trusting client-side role information
route.get('/admin/reports', (req, res) => {
  if (req.body.isAdmin === true) {
    res.json(sensitiveData);
  }
});

// Good: Verifying permissions server-side
route.get('/admin/reports', authenticate, authorize(['admin']), (req, res) => {
  // Verify user's actual role from database or token
  const user = verifyTokenAndGetUser(req.headers.authorization);
  if (!user.roles.includes('admin')) {
    return res.status(403).json({ error: 'Forbidden' });
  }
  res.json(sensitiveData);
});

Every endpoint needs server-side permission checks. Every one. Client-side validation is UX, not security.

2. Injection Attacks (A03)

Injection remains lethal because it's still common. Parameterized queries and prepared statements are non-negotiable.

pythonCopy
# Bad: String concatenation
query = f"SELECT * FROM users WHERE email = '{email}';"
result = db.execute(query)

# Good: Parameterized query
query = "SELECT * FROM users WHERE email = %s;"
result = db.execute(query, (email,))

Use your framework's built-in ORM or query builder. Never concatenate user input into SQL strings.

3. Cryptographic Failures (A02)

This catches outdated encryption, weak hashing, and exposed credentials. Audit your password storage immediately.

bashCopy
# Check for hardcoded secrets in your repo
git log -p | grep -i "password\|api_key\|secret"

# Use a tool like TruffleHog
trufflehog filesystem . --json

Rotate any exposed credentials, enforce bcrypt or Argon2 for password hashing, and use environment variables for secrets.

Where to Start

You can't fix everything at once. Prioritize by:

1. Business impact: Which vulnerabilities affect your highest-value data or most critical users?
2. Exploitability: Access control and injection are trivial to exploit. Prioritize these.
3. Effort: Some fixes take an afternoon (enabling HTTPS, adding security headers). Do these first for quick wins.

At LavaPi, we've found that teams who start with access control and injection attacks build momentum—these fixes often reveal architectural patterns that help secure the rest of the application.

The Takeaway

The 2024 Top 10 isn't a radical departure; it's a recalibration. The fundamentals haven't changed: verify user input, authenticate properly, authorize strictly, and encrypt sensitive data. What's changed is which vulnerabilities are hitting production systems hardest right now.

Start with access control and injection. Give those two weeks of focused effort. Then move down the list. That's the fastest path to a meaningfully more secure application.