9/22/2025 • 6 min read
Vulnerabilities Crash Course
Understanding common security vulnerabilities is the foundation of building secure applications. This crash course provides a high-level overview of the most critical vulnerability categories and points you to comprehensive resources for deeper learning.
This overview covers the essential vulnerability categories every developer should know, with links to detailed guides for each topic. Think of this as your security roadmap to comprehensive vulnerability knowledge.
What You'll Learn
This comprehensive crash course covers:
- The 5 most critical vulnerability categories
- OWASP Top 10 vulnerabilities overview
- API key and credential exposure risks
- Injection vulnerabilities overview
- Authentication and access control flaws
- Security misconfigurations
- Where to find detailed guides for each category
The 5 Most Critical Vulnerability Categories
These represent the most critical security risk categories that we believe every developer should understand. Each category contains multiple specific vulnerability types that require detailed study.
Note: For another comprehensive overview of vulnerability types, see our OWASP Ultimate Guide which covers the complete OWASP Top 10 and beyond.
1. Broken Access Control
What it is: When users can access resources they shouldn't have permission to view or modify.
Key Risk Areas:
- Direct object references without authorization checks
- Privilege escalation attacks
- Directory traversal vulnerabilities
- Horizontal and vertical access control bypasses
Why It Matters: Access control failures are the #1 security risk according to OWASP, affecting nearly every web application.
Deep Dive: For comprehensive coverage of all access control vulnerabilities, prevention techniques, and real-world examples, see our Broken Access Control Guide.
2. Cryptographic Failures
What it is: When sensitive data is not properly protected through encryption or hashing.
Key Risk Areas:
- Storing passwords in plain text
- Using weak encryption algorithms
- Transmitting sensitive data over unencrypted connections
- Weak random number generation
- Insecure key management
Why It Matters: Cryptographic failures expose the most sensitive data in your application, including user credentials and personal information.
Deep Dive: For a practical look at how cryptographic failures happen in real-world development, and why security can't be an afterthought, check out our Cryptographic Failures Guide. It covers common mistakes, their impact, and how to avoid them when building fast.
3. Injection
What it is: When untrusted data is sent to an interpreter as part of a command or query.
Key Risk Areas:
- SQL Injection
- NoSQL Injection
- Command Injection
- LDAP Injection
- XPath Injection
- Template Injection
Why It Matters: Injection attacks can compromise your entire database, execute system commands, or bypass authentication systems.
Deep Dive: For comprehensive coverage of all injection attack types, prevention techniques, and secure coding patterns, see our Injection Attacks Guide.
4. API Key and Credential Exposure
What it is: When sensitive credentials, API keys, or authentication tokens are exposed or mishandled.
Key Risk Areas:
- Hardcoded API keys in source code
- Exposed credentials in version control
- Insecure credential storage
- Weak API key management
- Insufficient credential rotation
Why It Matters: Exposed credentials provide attackers with direct access to your systems and third-party services, often bypassing all other security controls.
Deep Dive: For comprehensive coverage of API key security, credential management best practices, and detection techniques, see our API Key Leak Detection Guide and Authentication & Authorization Guide.
5. Security Misconfiguration
What it is: When security settings are not properly configured or maintained.
Key Risk Areas:
- Default passwords and configurations
- Unnecessary services and ports enabled
- Missing security headers
- Insecure default settings
- Unpatched systems and components
Why It Matters: Misconfigurations provide easy entry points for attackers and are often the result of oversight rather than complex vulnerabilities.
Deep Dive: For comprehensive coverage of security misconfigurations, common mistakes, and prevention strategies, see our Security Misconfiguration Guide.
Additional Critical Vulnerability Categories
Beyond these top 5 categories, there are several other critical vulnerability types that deserve attention:
Server-Side Request Forgery (SSRF)
Risk: Allows attackers to make requests to internal systems Impact: Can lead to internal network reconnaissance and data exfiltration
XML External Entity (XXE)
Risk: XML parsers processing external entities from untrusted sources Impact: Can lead to file system access and denial of service
Insecure Deserialization
Risk: Untrusted data deserialized without proper validation Impact: Can lead to remote code execution and data tampering
Cross-Site Scripting (XSS)
Risk: Untrusted data executed as scripts in user browsers Impact: Session hijacking, credential theft, and malicious redirects
Security Best Practices Overview
While each vulnerability category requires specific prevention techniques, there are fundamental security practices that apply across all categories:
Core Security Principles
- Input Validation: Always validate and sanitize user input
- Output Encoding: Properly encode output to prevent injection attacks
- Error Handling: Don't expose sensitive information in error messages
- Authentication: Implement strong authentication mechanisms
- Authorization: Enforce proper access controls
- Logging: Maintain comprehensive security logs
Development Lifecycle Integration
- Security by Design: Include security considerations from the beginning
- Code Reviews: Conduct security-focused code reviews
- Testing: Integrate security testing into your development process
- Monitoring: Implement continuous security monitoring
Detailed Implementation: For comprehensive secure coding practices, prevention techniques, and implementation examples, see our OWASP Ultimate Guide for complete coverage of secure coding practices.
Vulnerability Detection and Testing
Testing Approaches
Manual Testing
- Security-focused code reviews
- Penetration testing
- Threat modeling exercises
Automated Testing
- Static Application Security Testing (SAST)
- Dynamic Application Security Testing (DAST)
- Dependency scanning
- Security linting tools
Continuous Security
- Integrate security testing into CI/CD pipelines
- Regular security assessments
- Monitor for new vulnerabilities in dependencies
Automated Detection: The easiest way to detect vulnerabilities is to use Rafter - it automatically scans your code for these critical vulnerabilities and gives you actionable insights to fix them.
Remember: Security is not a one-time activity. It requires continuous attention and improvement throughout the development lifecycle.
Getting Started
Ready to improve your application's security? Here's your action plan:
- Start with Detection: Use Rafter to automatically scan your code for these critical vulnerabilities
- Implement Security Practices: Apply the fundamental security principles covered in our guides
- Build Security into Development: Integrate security testing into your development process
- Continuous Improvement: Regularly assess and enhance your security posture
The key to effective security is understanding the threat landscape and implementing appropriate defenses. Start with the basics covered in this overview, then dive deeper into specific vulnerability categories using our comprehensive guides.
Want to automatically detect vulnerabilities in your code? Try Rafter to scan your repositories and identify security issues before they become problems.