Before you run a real test against a web application — whether with Burp Suite, sqlmap, or any other tool — you need to know exactly what you're looking for. OWASP (the Open Worldwide Application Security Project) is a non-profit organization that periodically publishes a list of the ten vulnerability categories that pose the greatest risk to web applications, based on real data from thousands of applications worldwide. This list, known as the OWASP Top 10, has become one of the most authoritative standards in web security — underpinning many security assessment frameworks, certification exams, and formal penetration-testing contracts.
Unlike most tutorials in this section, this article isn't built around a single tool — it's a conceptual map. The goal is that after reading it, you understand where each vulnerability comes from, why it's dangerous, and most importantly, how to prevent it in code you write or manage yourself.
1. Broken Access Control
Occurs when a user can access resources or actions they shouldn't be able to — for example, by changing a simple number in a URL (/user/1001 to /user/1002) to reach another user's account data. It's one of the most common, and ironically one of the easiest, vulnerabilities to exploit, since it requires no deep technical knowledge.
2. Cryptographic Failures
Includes storing passwords in plain text, using old, broken cryptographic algorithms (like MD5 for password hashing), or transmitting sensitive data over HTTP instead of HTTPS. The result: even if an attacker gains access to the database or network traffic, the data remains usable.
3. Injection
A large family of vulnerabilities: SQL Injection, Command Injection, and similar — occurring when user input is fed directly into a query or system command without validation or sanitization. The sqlmap tutorial in this section focuses exactly on this category.
4. Insecure Design
Unlike code bugs, this refers to flawed architectural decisions from the start — a system with no limit on login attempts, for example, is inherently insecure by design, no matter how cleanly the code is written.
5. Security Misconfiguration
From overly detailed error messages that leak internal server information, to admin panels left with factory-default credentials. This category is often the most common finding in real-world penetration tests, since it usually stems from oversight rather than a technical weakness.
6. Vulnerable and Outdated Components
Using a JavaScript library, a WordPress plugin, or even an old PHP version with a known, public vulnerability. Attackers frequently scan for outdated versions of well-known software, since exploits for them are already public and ready to use.
7. Identification and Authentication Failures
Includes allowing weak passwords, no account lockout after repeated failed attempts, and poor session management — such as login tokens that aren't invalidated after logout.
8. Software and Data Integrity Failures
When an application trusts libraries, updates, or external data without verifying their integrity (e.g., a digital signature) — a door that can lead to supply-chain attacks.
9. Security Logging and Monitoring Failures
If a breach happens but nothing gets logged, the security team never finds out an attack occurred — this is exactly why many breaches continue undetected for months.
10. Server-Side Request Forgery (SSRF)
When a web application, without adequate validation, sends a request on behalf of the user to a URL the user themselves controls — and an attacker uses this to reach internal network resources that should never be accessible from outside.
Why understand this list instead of just memorizing it?
The important thing is that this list gets revised every few years (most recently in 2021), and the order — even the titles — change. What stays constant is the mindset behind it: always look at your application's inputs from an attacker's perspective, and always assume any data coming from a user is invalid until proven otherwise. That exact mindset is the backbone of my security and penetration-testing courses — before learning any tool, this mental model has to be in place first.
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