Binary Analysis and Exploitation of PicoCTF Challenges

Personal project exploiting PicoCTF binary challenges to develop vulnerability research and reverse engineering skills.

Disclaimer

This repository contains writeups, exploit scripts, and research based solely on educational Capture The Flag (CTF) challenges, primarily from picoCTF.
All binaries involved are intentionally vulnerable and executed in sandboxed environments.
No real-world software, services, or systems were targeted.
This work is strictly for ethical skill development and legal, academic purposes.
I do not condone or engage in any unauthorized or malicious activity.

Important Note

Each challenge folder is structured to include the relevant binary and its corresponding exploit.py script, where applicable.
If a folder does not include an exploit.py, it's either:

• A trivial challenge not requiring a custom exploit, or
• A challenge that was hosted on PicoCTF's remote servers, where local exploitation wasn’t possible.

What I'm Learning

Reverse Engineering

• Static analysis with Ghidra and IDA
• Dynamic debugging with GDB
• Assembly code analysis (x86/x64)

Binary Exploitation

• Buffer overflows and format strings
• ROP chains and memory corruption
• Environment manipulation and path injection
• Shell escapes from restricted environments

Tools Used

• Disassemblers: Ghidra, objdump, readelf
• Debuggers: GDB, PEDA
• Scripting: Python, pwntools
• Analysis: checksec, ROPgadget, strings

Repository Structure

├── Hash-Only-1-medium/     # PATH injection challenge
│   ├── writeup.md
│   └── flaghasher
├── Hash-Only-2-medium/     # Sequel with auto-execution
│   ├── writeup.md
│   └── flaghasher
├── Format-String-0-easy/   # Format string vulnerability
│   ├── writeup.md
│   └── binary
├── Heap-0-easy/           # Heap exploitation basics
│   ├── writeup.md
│   └── binary
├── PIE-writeup-easy/      # Position Independent Executable
│   ├── writeup.md
│   └── binary
├── exploit.py             # Pwntools exploit template/learning
└── GEF-cheatsheet.md      # GDB Enhanced Features reference

Challenges Completed

• Hash-Only Series: PATH hijacking and binary substitution
• Format String: Arbitrary read/write primitives
• Heap Exploitation: Basic heap manipulation
• PIE Bypass: Position Independent Executable analysis

Skills Demonstrated

• Finding and exploiting binary vulnerabilities
• Reverse engineering unknown binaries
• Writing reliable exploit code
• Clear technical documentation