CASA Certification Review - APISec University

CASA - Certified API Security Analyst

Overview

The CASA certification, offered by APISec University, tests your ability to assess and respond to API vulnerabilities through scenario-based questions. Rather than focusing on definitions or trivia, the exam challenges you to apply your understanding of the OWASP API Top 10 to real-world situations.

This makes it a great choice for red teamers, blue teamers, and developers alike. Anyone working with APIs will benefit from seeing vulnerabilities through different lenses.

Exam Format

• Length: 100 multiple-choice questions
• Time Limit: 2 hours
• Cost: $125 for the initial attempt, $75 for retakes
• Instructor: Corey Ball
• Study Material: OWASP API Security Top 10 and Beyond!

While the exam isn’t strictly enforced as open- or closed-book, I approached it with the intent of treating it as closed-book to better reflect real understanding. According to a team member at APISec University, the format is meant to be flexible. Some roles benefit from open-book problem solving, while others, like offensive security interviews, expect you to know the material without looking it up. I ended up scoring 97 out of 100 in just over an hour without needing to reference outside material.

Preparation

Recommended Study

The only recommended resource is APISec University’s course:

OWASP API Security Top 10 and Beyond!

This course is taught by Corey Ball and covers the OWASP API Top 10, which form the foundation of the exam:

• API1: Broken Object Level Authorization (BOLA)
• API2: Broken Authentication
• API3: Broken Object Property Level Authorization (BOPLA)
• API4: Unrestricted Resource Consumption
• API5: Broken Function Level Authorization
• API6: Unrestricted Access to Sensitive Business Flows
• API7: Server-Side Request Forgery (SSRF)
• API8: Security Misconfiguration
• API9: Improper Inventory Management
• API10: Unsafe Consumption of APIs

The course provides examples that align closely with the exam format, helping you understand how each vulnerability manifests in real-world API scenarios.

Skills That Helped

• Translating behavioral clues into vulnerability types
• Discerning subtle differences between similar OWASP categories
• Understanding API logic flaws, not just classic web bugs
• Applying offensive and defensive perspectives to API security

Exam Experience

The test felt straightforward and fair. Most questions were scenario-based, requiring you to think through the implications rather than guess terms. Nothing felt like filler or trick phrasing.

It’s not a hands-on exam, but it still demands real understanding—not just memorization. You’ll do well if you’ve read through the OWASP Top 10 a few times and worked with APIs before.

Final Thoughts

Whether you’re hunting bugs, defending endpoints, or building APIs from scratch, CASA gives you a meaningful benchmark for understanding modern API threats. It’s affordable, practical, and backed by solid instruction.

Highly recommended for:

• Red teamers looking to expand their API abuse knowledge
• Blue teamers working to defend against modern API threats
• Developers who want to build more secure APIs by learning how they’re attacked

Pros and Cons

✅ Pros

• Scenario-based questions test real understanding, not memorization
• Well-aligned course that’s short, free, and practical
• Applicable to red teamers, blue teamers, and developers alike
• Affordable price for the value it provides
• Clean, fair exam experience with no trick questions

❌ Cons

• No hands-on component for those who prefer practical testing
• Some OWASP categories feel overlapping if you’re unfamiliar
• Not as widely recognized (yet) as traditional certs like OSCP or eJPT

Final Score

🧠 Knowledge Depth: ★★★★☆
💰 Value for Cost: ★★★★★
📚 Study Requirements: ★★☆☆☆
🧪 Real-World Applicability: ★★★★☆

Overall Rating: 3.75 / 5

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Note: AI-assisted editing was used to improve grammar, clarity, and formatting. All technical content and opinions are original.