Web applications are a primary target for attackers, and most real-world attacks follow common vulnerability patterns. To help organizations and developers focus on the most critical risks, OWASP publishes the OWASP Top 10.
This post provides a deep, easy-to-understand explanation of OWASP Top 10 Web Application Security Risks (2021), exactly as shown in the reference image, with examples and security insights.
What is OWASP?
OWASP (Open Web Application Security Project) is a non-profit organization focused on improving software security. The OWASP Top 10 is a globally recognized list of the most critical web application security risks.
It is widely used by:
- Developers
- Security engineers
- Penetration testers
- Cybersecurity students
OWASP Top 10 Web Application Security Risks (2021)
A01: Broken Access Control
Broken Access Control occurs when an application fails to properly enforce user permissions. This allows users to perform actions outside their intended privileges.
Examples
- Accessing another user's data by changing an ID in the URL
- Normal users accessing admin pages
- Privilege escalation attacks
Impact
Attackers can view, modify, or delete sensitive data.
A02: Cryptographic Failures
Cryptographic Failures occur when sensitive data is not properly protected using encryption. Previously known as Sensitive Data Exposure.
Examples
- Passwords stored in plain text
- Weak encryption algorithms
- No HTTPS (TLS) used
Impact
Leads to data breaches, identity theft, and financial loss.
A03: Injection
Injection vulnerabilities occur when untrusted data is sent to an interpreter as part of a command or query.
Common Types
- SQL Injection
- Command Injection
- LDAP Injection
Example
An attacker injects SQL code into input fields to bypass authentication or extract database data.
A04: Insecure Design
Insecure Design refers to flaws in the application architecture rather than coding mistakes. Security was not considered during the design phase.
Examples
- No rate limiting
- Missing business logic validation
- Lack of threat modeling
Key Point
Security cannot be added later if the design itself is insecure.
A05: Security Misconfiguration
Security Misconfiguration happens when security settings are incorrectly defined or left at default values.
Examples
- Default admin credentials
- Open cloud storage
- Verbose error messages
Impact
Attackers can easily exploit misconfigured systems.
A06: Vulnerable and Outdated Components
Using outdated libraries, frameworks, or components with known vulnerabilities puts applications at high risk.
Examples
- Outdated CMS plugins
- Old JavaScript libraries
- Unpatched frameworks
Impact
Attackers exploit publicly known vulnerabilities.
A07: Identification and Authentication Failures
Occurs when authentication mechanisms are weak or improperly implemented.
Examples
- Weak passwords
- No account lockout
- Session fixation
Impact
Leads to account takeover and identity compromise.
A08: Software and Data Integrity Failures
Occurs when applications rely on untrusted sources for software updates or data without verifying integrity.
Examples
- Compromised CI/CD pipelines
- Unsigned software updates
- Malicious third-party libraries
Impact
Allows attackers to inject malicious code into systems.
A09: Security Logging and Monitoring Failures
Occurs when systems do not properly log or monitor security-related events.
Examples
- No login attempt logging
- No alerting on suspicious behavior
- Logs not reviewed
Impact
Attacks go undetected for long periods.
A10: Server-Side Request Forgery (SSRF)
SSRF occurs when a web application fetches a remote resource based on user input without validation.
Examples
- Accessing internal cloud metadata
- Scanning internal networks
Impact
Can lead to internal system compromise.
Why OWASP Top 10 is Important
- Improves secure coding practices
- Helps prevent real-world attacks
- Essential for cybersecurity exams
- Widely adopted by organizations
OWASP Top 10 for Certifications
OWASP Top 10 is heavily used in:
- CEH
- Security+
- OSCP
- Bug bounty programs
Conclusion
The OWASP Top 10 provides a strong foundation for understanding web application security. By learning these risks, developers and security professionals can build safer applications and defend against common attacks.
Master OWASP Top 10 = Strong Web Security Fundamentals 🚀
