ODC_23-24-CTFs - All CTFs solved in Offensive and Defensive Cyber S

项目说明

ODC_23-24-CTFs <!-- omit in toc -->

> POLIMI Offensive and Defensi (ODC) 23/24 course's CTFs solved

1. About

- 1.1. What is a CTF?
- 1.2. What is a "flag"?
- 1.3. What are the macro-topics?
- 1.4. 23/24 ODC CTFs

2. File structure and con

3. Usage

4. Contibutions

- 4.1. Enhancement
- 4.2. New exploit

5. Meta

1. About

1.1. What is a CTF?

Capture The Flag (CTF) is a cybersecurity challenge that in participants finding a designated flag. The flag is acquired when a participant successfully gains control of the organizer's publicly machine. Typically, CTFs are organized into macro-topics within a jeopardy-style competition, allowing indi or teams to participate through the central organizer's online platform. Additionally, other cybersecurity competitions, such as "Attack/Defense" or "King of the Hill," also exist.

1.2. What is a "flag"?

A flag typically consists of a unique and non-trivial string of characters and symbols stored in a file named "flag". This file is configured to be readable exclusively by the organizers, accessible only through the "root" account (also known as "superuser" or "admin") on the machine. The term "taking control" refers to the successful attainment of root pri on the machine. Reading the flag and subsequently reporting it to the organizers serves as a harmless proof of accomplishment.

1.3. What are the macro-topics?

Competitions may encompass one or more macro-topics, which can include areas such as cryptography, reverse engineering, binary exploitation, web application security, steganography/forensics, mobile security, and other related domains.

1.4. 23/24 ODC CTFs

POLITECNICO DI MILANO (POLIMI) offers an ad technical course on Cybersecurity: "Offensive and Defensi".
All along the course, students are being presented with CTFs comprising these topics in macro-topics:
- shellcode (binary exploitation)
- re (reverse engineering)
- mitigations (mitigations bypass, binary exploitation)
- ROP (Return Oriented Programming, binary exploitation)
- HEAP (HEAP exploitation, binary exploitation)
- symbolic (symbolic execution, binary exploitation)
- race (race conditions, web app exploitation)
- serialization (serialization, web app exploitation)
- XSS (cross-site scripting, web exploitation)
- malware (packing, binary analysis)

to solve by applying what has been learned in class.
Final exam consists in an actual free-for-all live CTF competition of 7 hours long.

2. File structure and con

CTFs are organized in subdirectories, grouped inside parent directories reflecting each topic.

Inside each CTF directory, you can usually find (depending on the macro-topic):
- notes.txt: a text file within all my notes taken live.
- The executable file: the binary to be exploited. It has no file extension. Usually, source code is not given.
- *.mod: modified of the executable
- script.py: the Python exploiting script. The main entry point file of every CTF directory. Usually, you should run it once and get to output the flag.
- payload: optional file with malicious content. It is used by script.py.
- libc*.so and ld*.so: sometimes, it is also given the standard C library and loader, supposed to run with the executable.
- src/ or html or htdocs: folder containing the source code. Usually given for web app exploitation.
- explanation.md: text markdown file in which it is clearly detailed the exploit in steps.
- An optional child directory named after a *contributor* with a different exploit inside.

3. Usage

Challenges are hosted at under form of provided services.

NOTE: Before running any file, check if the service is up by sending a TCP request: nc -z} {port}.

script.py should interact with the service, exploit it and printing the flag. You can consult documentation on the CTF by reading the explanation.md file.

4. Contibutions

Contributions are more than welcome! Here's a short video tutorial on how to open a *pull request*.

4.1. Enhancement

If you just thought something could have been done better or you want to fix a mistake, In the pull request, write a brief description of what you *enhanced*.

4.2. New exploit

If you want to submit a new exploit, follow these steps:
1. Create a subdirectory with your name in your desired specific CTF folder: foo/CTF$: mkdir {name}
2. Inside that directory, there should be at least:
- One script.py file with your exploit inside it.
- One explanation.txt with a clear and concise explanation in steps of your exploit.
- You can add any other file you think will be useful.
3. State in the pull request message that it is a "New exploit" contribution.

5. Meta

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项目信息

开发语言：Python

Star 数：2

技术要点

该项目属于防护思路方向的开源资源，代码结构清晰，适合安全研究人员学习参考。项目围绕All CTFs solved in Offensive and Defensive Cyber Security course of Polytechnic of Milan 23/24 edition展开，提供了可运行的实现，对理解相关安全机制、工具原理与攻防技术具有较高的研究价值。

从技术实现角度看，此类项目的核心在于对底层原理的深入理解与工程化落地。开发者在研究过程中可以结合官方文档与社区讨论，梳理项目的初始化流程、核心模块职责与数据流转，逐步掌握其中的技术细节与设计思路。

使用与学习建议

1. 下载源码压缩包，解压到本地环境。

2. 根据项目类型准备对应的运行环境与依赖。

3. 按照 README 中的步骤完成配置与部署。

4. 在隔离的测试环境中运行验证，避免影响生产系统。

免责声明

本资源来源于开源社区，仅供安全研究、技术学习与合法授权范围内的攻防演练使用，请勿用于任何非法或侵害他人权益的用途。使用本项目产生的一切后果由使用者自行承担。