Understanding the OWASP Top 10: Key Web Vulnerabilities Explained

If you’ve ever wondered how hackers break into websites or apps, it usually comes down to one thing: vulnerabilities in the code or system setup. That’s where the OWASP Top 10 comes in — it’s like the cybersecurity world’s “most wanted” list for web application threats.

In this post, we’ll go over each of the top 10 web vulnerabilities as listed by OWASP, explain what they are in plain English, and how developers or security professionals can avoid them.

Let’s dive right in.

Prefer watching instead of reading? Here’s a quick video guide

1. Broken Access Control

What’s happening:
Users can do things they’re not supposed to — like seeing other users’ data or performing admin actions.

Real-life analogy:
Picture logging into your school portal and having access to the principal's dashboard by modifying the URL.

Why it's dangerous:
Attackers can steal or modify other individuals' information, or even hijack sections of the app.

How to remediate:

• Make proper permission checks on each request.
• Enforce role-based access.
• Don't rely on front-end logic alone.

2. Cryptographic Failures

What's going on:
Sensitive information (such as passwords or credit card numbers) isn't being correctly encrypted.

Real-life analogy:
It's similar to putting your password on a post-it note and leaving it on your desk.

Why it's dangerous:
Attackers can read or steal this information during a breach or during transmission.

How to remedy:

• Use HTTPS.
• Hash passwords using bcrypt or Argon2.
• Encrypt sensitive data with strong ciphers (such as AES-256).

3. Injection (SQL, NoSQL, OS)

What's occurring:
Attackers inject malicious input into your application, and your application runs it blindly.

Real-world analogy:
Imagine instructing your assistant to order "one pizza"; rather, they overhear "one pizza and pass my bank information to this person" — and they simply obey.

Why it's dangerous:
Hackers can bypass login forms, steal data, or even delete your database.

How to repair it:

• Use prepared statements.
• Validate and sanitize all inputs.
• Don't dynamically construct queries from user input.

4. Insecure Design

What's going on:
The app is broken by design — even if the code is good, the logic is poor.

Real-world analogy:
A bank that allows you to change your PIN without asking for any ID check — it is doing its job, but it is not secure.

Why it's risky:
Attackers don't need to use the bugs — they simply employ the faulty logic.

How to improve:

• Utilize secure design patterns.
• Conduct threat modeling upfront.
• Don't overlook business logic issues.

5. Security Misconfiguration

What's going on:
Apps or servers are left in a default or exposed state.

Real-life analogy:
Installing a home security system but leaving the default password “1234”.

Why it’s risky:
Attackers can easily find and exploit these weak points.

How to fix it:

• Disable unnecessary features or ports.
• Change default credentials.
• Use automated configuration scanning tools.

6. Vulnerable and Outdated Components

What’s happening:
You’re using libraries or plugins with known security issues.

Real-life analogy:
Utilizing a rusty lock on your front door when newer, more secure ones are available.

Why it's risky:
Hackers look for these older components all the time.

How to fix it:

• Keep all dependencies up to date.
• Eliminate unused components.
• Watch for advisories of new vulnerabilities.

7. Identification and Authentication Failures

What's happening:
Login systems do not do enough to authenticate users or prevent abuse.

Real-life analogy:
Inviting someone into your home because they claim to live there — no ID check.

Why it's risky:
Attackers can hijack user accounts or impersonate someone.

How to fix it:

• Enforce strong password policies.
• Implement two-factor authentication (2FA).
• Limit failed login attempts and detect brute-force attacks.

8. Software and Data Integrity Failures

What's happening:
The system doesn't check where updates or code are coming from — and attackers can slip in malicious changes.

Real-life analogy:
Installing a software update from a random USB you picked up on the street.

Why it's risky:
Leads to malware injection, supply chain attacks, and backdoors.

How to fix it:

• Utilize signed updates.
• Verify code integrity prior to execution.
• Utilize trusted sources for third-party packages.

9. Security Logging and Monitoring Failures

What's happening:
Attacks go undetected because there's no adequate logging or alert system.

Real-life analogy:
A store with no cameras or alarms — someone could steal from it and nobody would know.

Why it's risky:
Security incidents may not be detected until harm is caused.

How to fix it:

• Log significant activity (such as logins, errors, denied access attempts).
• Implement alerts for anomalous behavior.
• Periodically exercise your incident response plan.

10. Server-Side Request Forgery (SSRF)

What's happening:
The application retrieves a URL provided by the attacker — and can be deceived into accessing internal resources.

Real-life analogy:
Giving someone your house keys and they rummage through your private documents because you didn't restrict access.

Why it's risky:
Can be used to expose internal servers, cloud metadata, or deeper attacks.

How to solve it:

• Don't allow users to control where the server requests.
• Check and whitelist destination URLs.
• Block requests to internal IP ranges where feasible.

Wrapping Up: Why the OWASP Top 10 Matters

The OWASP Top 10 is not a list — it's a foundation for developing secure apps and how hackers think. As a developer, knowing these risks makes you code safer. As someone learning about cybersecurity, being able to conquer these 10 gives you a good base to start penetration testing or bug bounty hunting.

Security isn't a one-and-done — it's a process. The best you can do is design with security from day one and keep current with changing threats.

Quick Checklist:

• Validate inputs
• Encrypt sensitive data
• Keep software updated
• Use strong authentication
• Monitor and log activity
• Think like an attacker

Want to dive deeper? Check out the official site: OWASP Top 10