In this Practical Academy lecture, we walk through how to build a custom Python exploit script using pwntools to create a working buffer overflow payload and hijack control of program execution in a lab environment.

This lesson introduces the core building blocks of payload development, including pwntools basics like process(), sendline(), and cyclic(). Students will learn how to structure an exploit payload with buffer padding, an EIP overwrite, and additional junk or NOP-style filler to demonstrate controlled execution flow. We also discuss how to simulate a return address overwrite without requiring a shell, and optionally introduce the role of shellcode or simulated return instructions in exploit development.

Along the way, students will learn how to interpret program behavior after the exploit is delivered, how to confirm control over execution, and why real-world protections such as ASLR, NX, Stack Canaries, and RELRO can limit or prevent exploitation. This lecture builds directly on crash analysis and stack debugging and moves students closer to writing complete exploit proofs of concept.

By the end of this video, students will be able to write a Python script that generates a working overflow against the lab binary, verify control of execution, and clearly explain the structure of the payload they created.

Disclaimer:
This video is for educational purposes only and is part of Practical Academy’s ethical hacking curriculum. All demonstrations, exploit code, payload development, and testing shown in this video are intended only for authorized lab environments, classroom exercises, and defensive cybersecurity education. Do not use these techniques, tools, or scripts on systems, software, or networks without explicit permission.