🛡️ # CVE-2025-5548 – FreeFloat FTP Server Buffer Overflow Exploit

📌 Overview

This repository documents the discovery and exploitation of a stack-based buffer overflow vulnerability in the FreeFloat FTP Server application.

The vulnerability resides in the handling of the USER command, where unsafe memory operations (strcpy) allow an attacker to overwrite the stack and gain control over the execution flow.

This project demonstrates a complete exploitation workflow, from reverse engineering to arbitrary code execution.

🎯 Vulnerability Details

• Target Software: FreeFloat FTP Server (Win32)
• Vulnerability Type: Stack-Based Buffer Overflow
• Attack Vector: FTP USER command
• Impact: Remote Code Execution (RCE)
• Root Cause: Unsafe memory handling (strcpy without bounds checking)

🧠 Exploitation Summary

The exploitation process follows these steps:

1. Reverse engineering of the binary
2. Identification of the vulnerable function
3. Fuzzing to trigger a crash
4. Control of the Instruction Pointer (EIP)
5. Offset calculation using cyclic patterns
6. Identification of bad characters
7. Discovery of a JMP ESP instruction
8. Payload crafting and execution
9. Shellcode execution

The final result is the successful execution of arbitrary code within the context of the vulnerable application.

📂 Repository Structure

.
├── 01-Environment/
│   └── environment.md
├── 02-Exploitation/
│   └── exploitation.md
├── Images/
│   └── exploit_01_...
└── README.md

🛠️ Tools Used

• Immunity Debugger
• Mona.py
• IDA Free
• Python 3
• FreeFloat FTP Server

🚀 Getting Started

1. Run the vulnerable FTP server
2. Attach Immunity Debugger to the process
3. Follow the exploitation steps in:

👉 02-Exploitation/exploitation.md

⚠️ Disclaimer

This repository is intended for educational and research purposes only.

The techniques demonstrated here should only be used in controlled environments and never against systems without proper authorization.

👨‍💻 Author

Jesús Gómez Sánchez