OffSec OSWE Study Guide: Everything You Need to Pass the WEB-300 Exam

The OffSec OSWE certification validates your expertise and opens doors to higher-paying roles in IT and cybersecurity. Whether you are just starting your study journey or doing a final review, this guide breaks down everything you need to know to pass the WEB-300 exam.

Exam Overview

• Certification: OffSec OSWE
• Exam Code: WEB-300
• Vendor: OffSec
• Cost: $1,749 USD (course + exam)
• Duration: 48-hour proctored exam + report
• Questions: Hands-on practical exam
• Passing Score: Pass/Fail
• Format: Hands-on white-box web application testing with written report
• Prerequisites: No formal certification required. OffSec recommends comfort reading and writing at least one coding language, Linux familiarity, and experience with web proxies and web attack vectors
• Validity: Does not expire

Domain Breakdown

The topic areas below are FixTheVuln's grouping of the WEB-300 material, not an official weighting.

Topic area 1: Advanced Web Application Source Code Review

• 1.1 Perform systematic source code review of web applications
• 1.2 Identify vulnerabilities in multiple programming languages
• 1.3 Trace data flow from user input to dangerous sinks
• 1.4 Analyze application logic for business logic flaws

Key concepts: Source Code Review, Data Flow Analysis, Taint Tracking, Code Auditing Tools, Language-Specific Patterns, MVC Architecture, ORM Vulnerabilities, Input Sources/Sinks

Topic area 2: Authentication Bypass

• 2.1 Identify and exploit authentication bypass vulnerabilities in source code
• 2.2 Exploit type juggling and loose comparison vulnerabilities
• 2.3 Attack custom authentication implementations
• 2.4 Chain multiple flaws to achieve authentication bypass

Key concepts: Type Juggling, Loose Comparison, JWT Manipulation, Session Token Prediction, Password Reset Flaws, OAuth Implementation Bugs, SSO Bypass, Role Manipulation

Topic area 3: Advanced SQL/NoSQL Injection

• 3.1 Identify SQL injection through source code analysis
• 3.2 Exploit complex SQL injection scenarios with filters
• 3.3 Perform NoSQL injection against document databases
• 3.4 Write custom exploitation scripts for data extraction

Key concepts: Parameterized Query Bypass, ORM Injection, Stored Procedure Exploitation, NoSQL Injection (MongoDB), Second-Order SQLi, Out-of-Band Extraction, WAF Bypass Techniques, Custom Exploit Scripts

Topic area 4: Deserialization Attacks

• 4.1 Identify insecure deserialization in Java, PHP, and .NET applications
• 4.2 Construct exploitation gadget chains
• 4.3 Exploit deserialization for remote code execution
• 4.4 Analyze serialization formats and custom protocols

Key concepts: Java Deserialization, PHP Object Injection, .NET Deserialization, Gadget Chains, ysoserial, PHPGGC, Magic Methods, Serialization Formats

Topic area 5: Server-Side Template Injection & RCE

• 5.1 Identify server-side template injection vulnerabilities
• 5.2 Exploit SSTI across different template engines
• 5.3 Achieve remote code execution through application flaws
• 5.4 Write custom exploit scripts for chained vulnerabilities

Key concepts: Jinja2 SSTI, Twig SSTI, Freemarker SSTI, Thymeleaf SSTI, Template Engine Sandboxes, Sandbox Escapes, RCE via File Write, RCE via Code Injection

Recommended Study Timeline

Plan for approximately 10-16 weeks of dedicated study. Here is a suggested weekly breakdown:

• Week 1: Topic area 1: Source code review fundamentals (Data flow, taint tracking, code auditing methodology)
• Week 2: Topic area 1: Language-specific patterns (PHP, Java, Python, .NET vulnerability patterns)
• Week 3: Topic area 2: Authentication bypass (Type juggling, loose comparison, JWT manipulation)
• Week 4: Topic area 2: Advanced auth attacks (Custom auth implementations, role manipulation, SSO bypass)
• Week 5: Topic area 3: Advanced SQLi (Source-level identification, parameterized query bypass, ORM injection)
• Week 6: Topic area 3: NoSQL injection (MongoDB, second-order SQLi, out-of-band extraction)
• Week 7: Topic area 3: Custom exploit scripting (Python scripts for automated data extraction)
• Week 8: Topic area 4: Deserialization (Java deserialization, ysoserial, gadget chain construction)
• Week 9: Topic area 4: PHP/NET deserialization (Object injection, PHPGGC, .NET gadgets, magic methods)
• Week 10: Topic area 5: SSTI (Jinja2, Twig, Freemarker, Thymeleaf exploitation and sandbox escapes)
• Week 11: Topic area 5: RCE techniques (Exploit chaining, file write RCE, custom exploit development)
• Week 12: Lab Practice: Source code review exercises, vulnerability identification drills
• Week 13: Lab Practice: Full application assessments, exploit development, chaining attacks
• Week 14: Lab Practice: Timed mock exam (Complete application compromise with report)
• Week 15: Report Writing: Professional report writing practice, methodology documentation
• Week 16: Final Review: Weak areas, exam strategy, tool preparation

Top Study Tips

1. Start with the official exam objectives. Download them from the OffSec website and use them as your study checklist. Every exam question maps to a specific objective.

1. Use active recall over passive reading. Instead of re-reading notes, test yourself with practice questions after each study session. This dramatically improves retention.

1. Start with your weakest topic areas. Score yourself on practice questions after each session, then spend the most time where you miss the most.

1. Build hands-on experience. Set up a lab environment and practice the skills you are studying. Hands-on experience is especially valuable for performance-based questions.

1. Take practice exams under real conditions. Time yourself, eliminate distractions, and simulate the exam environment. Review every wrong answer and understand why it was wrong.

Practice Resources

Test your knowledge with our free tools:

Take our free OffSec OSWE practice quiz

• CVSS Calculator: Practice scoring vulnerabilities
• Password Strength Checker: Test password security

Career Impact

The OffSec OSWE certification demonstrates validated expertise to employers. Certified professionals typically see:

• Higher starting salaries compared to non-certified peers
• More interview callbacks as the certification signals commitment and competence
• Faster career progression with a recognized credential on your resume
• Access to roles that specifically require or prefer OffSec OSWE certification

What to Study Next

After earning your OffSec OSWE certification, consider these natural next steps:

• Deepen your specialization with an advanced certification in the same vendor track
• Broaden your skills with a certification from a complementary domain
• Visit our Career Paths page for detailed certification roadmaps

Get Organized with a Study Planner

A structured study plan makes the difference between passing and failing. Our fillable PDF study planners include domain trackers, weekly schedules, and progress tracking designed specifically for OffSec OSWE exam prep.

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This guide is independently created for educational purposes. OffSec trademarks belong to their respective owners. FixTheVuln is not affiliated with or endorsed by OffSec.