Introduction

Offensive Security Exploit Developer

OSED stands for Offensive Security Exploit Developer. It's a certification offered by Offensive Security that demonstrates the holder's ability to develop exploits for software vulnerabilities.

Key features of the OSED certification:

• Focus on exploit development: The certification emphasizes the practical skills needed to create exploits from scratch, including writing shellcode and bypassing common security mitigations.

• Hands-on learning: The OSED course and exam involve extensive hands-on experience in a virtual lab environment.

• Challenging exam: The OSED exam is known for its difficulty and requires candidates to demonstrate their exploit development skills under pressure.

• Industry recognition: The OSED certification is highly respected in the cybersecurity industry and can open doors to advanced security roles.

The OSED focuses on teaching you how to develop exploits for software vulnerabilities, primarily in Windows user-mode applications. Here's a breakdown of the key areas covered:

1. Foundational Knowledge:

• Assembly Language: You'll gain a solid understanding of x86 assembly language, essential for analyzing code and writing shellcode.

• Python/C/C++ Programming: Strong Python/C/C++ skills are crucial for understanding vulnerable code and crafting exploits.

• Windows Internals: You'll delve into the inner workings of the Windows operating system, including memory management, process execution, and system calls.

• Debugging: Mastering debugging tools like WinDbg and Immunity Debugger is essential for analyzing crashes, identifying vulnerabilities, and developing exploits.

• Reverse Engineering: You'll learn techniques to reverse engineer software to understand its functionality and identify potential vulnerabilities.

2. Exploit Development Techniques:

• Stack Overflows: Exploiting stack-based buffer overflows, a classic vulnerability type.

• Structured Exception Handler (SEH) Overflows: Overwriting SEH structures to gain control of execution flow.

• Heap Overflows: Exploiting vulnerabilities in the heap memory manager.

• Format String Vulnerabilities: Leveraging format string functions to manipulate memory and execute code.

3. Bypassing Security Mitigations:

• Address Space Layout Randomization (ASLR): Techniques to bypass ASLR and achieve reliable code execution.

• Data Execution Prevention (DEP): Methods like Return-Oriented Programming (ROP) to bypass DEP and execute code in memory marked as non-executable.

4. Shellcoding:

• Writing Shellcode: Developing custom shellcode to perform actions like spawning a reverse shell or executing arbitrary commands.

• Encoding Techniques: Encoding shellcode to avoid bad characters and bypass security filters.

5. Hands-on Practice:

• Vulnerable Applications: The OSED course provides access to a variety of vulnerable applications for you to practice your exploit development skills.

• Challenging Exercises: You'll face increasingly challenging exercises that require you to apply your knowledge and creativity to develop working exploits.

Tools and Technologies:

• Metasploit Framework: While the focus is on manual exploit development, you'll also learn how to use Metasploit for tasks like generating shellcode and encoding payloads.

• Python Scripting: Python is often used for automating tasks and developing exploit tools.

By covering these areas, the OSED provides a comprehensive understanding of exploit development techniques and equips you with the skills to identify, analyze, and exploit software vulnerabilities in real-world scenarios.