Dor-sketch / ASLR-StackSecDemos

Deep dives into ASLR and stack overflow vulnerabilities.

Security Demonstrations 🔒

This repository contains demonstrations of various security concepts, emphasizing Address Space Layout Randomization (ASLR), stack overflow, and virtual pointer (vptr) vulnerabilities.

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Table of Contents 📜

• 1️⃣ ASLR Demonstration
• 2️⃣ Stack Overflow Demonstration
• 3️⃣ Integer Overflow Demonstration
• 🗑 Cleaning Up
• 🤝 Contributing
• 🙏 Acknowledgment
• ⚠️ Disclaimer
• 📜 License
• 🧮 CIA: Confidentiality, Integrity, and Availability

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1️⃣ ASLR Demonstration

Overview 📝

ASLR is a computer security technique that randomizes the memory addresses used by processes. This makes it harder for an attacker to predict the location of specific functions or buffers they might target.

Features ⚙️

• Toggle ASLR: The program aslr_examp allows you to turn ASLR on or off on a Linux system. This is useful for visualizing the effects of ASLR on memory address allocations.

• Memory Address Visualization: The program print_mem is a helper utility that prints the memory address of a dynamically allocated variable, demonstrating the effect of enabling or disabling ASLR.

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Compilation and Usage 🛠

To compile the ASLR demonstration:

make aslr_examp print_mem

Run the ASLR demo:

./aslr_examp

2️⃣ Stack Overflow Demonstration

Overview 📝

The program stack_demo highlights vulnerabilities tied to stack overflow and vptr overwrites. By tampering with a class's virtual pointer (vptr), it can redirect its virtual function calls, thereby enabling unauthorized access.

User Input and Overflow 🎛

By default, the program uses a predefined buffer to demonstrate the overflow. But you also have the option to feed data manually or pipe it into the program, even though the default method is easier for demonstration purposes.

Compilation and Usage 🛠

To compile all the demonstrations at once, simply use:

make

Alternatively, you can use the Gtk GUI to compile the programs individually. To do so, run the following command:

g++ gui.cpp -o gui `pkg-config --cflags --libs gtk+-3.0` -lssl -lcrypto  -w -fno-stack-protector -g -no-pie -g3 -DNO_PIE

3️⃣ Integer Overflow Demonstration

The program int_overflow demonstrates the effects of integer overflow. It is compiled using the following command:

g++ int_overflow.cpp -o int_overflow

In C++ , when comparing an int to unsigned int, the int is converted to an unsigned int. This means that if the int is negative, it will be converted to a large positive number. This can lead to unexpected results, as demonstrated in the program.

int main() {
    int x = -1;
    unsigned int y = 1;
    if (x < y) {
        std::cout << "x is less than y" << std::endl;
    } else {
        std::cout << "x is greater than y" << std::endl;
    }
    return 0;
}

🗑 Cleaning Up

To clean up and remove the compiled binaries:

make clean

🤝 Contributing

If you'd like to contribute to this project, please fork the repository and submit a pull request.

🙏 Acknowledgment

The code examples in this repository are inspired by and built upon concepts studied in the Open University course "Defensive System-Programming (20937)".

⚠️ Disclaimer

The code in this repository is strictly for educational purposes. The demonstrated vulnerabilities aim to raise awareness and understanding of potential security risks. Do not use the code maliciously or without proper understanding. Ensure that you have necessary permissions before making system-level changes, such as modifying ASLR settings.

📜 License

This project is open-source and is licensed under the MIT License, which is available in the LICENSE file.

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🧮 CIA: Confidentiality, Integrity, and Availability

Key Concepts: Confidentiality, Integrity, and Availability

From "Modern Operating Systems" by Andrew S. Tanenbaum

• Confidentiality: Ensuring information is not disclosed to unauthorized individuals, entities, or processes.

• Integrity: Maintaining the accuracy and completeness of information.

• Availability: Ensuring information is accessible and usable upon demand by an authorized entity.

Comparative Analysis Table

Criteria / Service	Confidentiality	Integrity	Availability	Example Use Cases
Popular News Services	✘	✔	✔	Access to news, not typically confidential
Backup Storage Systems	✔	✔	Moderate	Secure storage, not always instantly available
Banking Services	✔	✔	✔	High standards for sensitive financial data