Now Reading: Crash Websites And Servers Using HTTP Flooding: How It Works, Methods, and Basic Attack Execution Using Cloud Shell


Crash Websites And Servers Using HTTP Flooding: How It Works, Methods, and Basic Attack Execution Using Cloud Shell

June 10, 202312 min read

Crash Websites And Servers Using HTTP Flooding: How It Works, Methods, and Basic Attack Execution Using Cloud Shell


HTTP flooding, also known as HTTP DoS (Denial of Service), is a type of cyber attack where an attacker overwhelms a target website or server by flooding it with a massive number of HTTP requests. The goal of this attack is to exhaust the server’s resources, such as bandwidth, processing power, or memory, causing the website or server to become unresponsive or crash. In this article, we will explore the inner workings of HTTP flooding, its methods, and how to perform a basic HTTP flooding attack using Kali Linux.

How HTTP Flood Works

HTTP flood attacks exploit the standard communication protocol between a client and a server. When a user accesses a website, their browser sends an HTTP request to the server, which then processes the request and sends back the appropriate response. In an HTTP flood attack, the attacker sends a large number of HTTP requests to the target server, causing it to become overwhelmed and unable to process legitimate requests from other users.

Explain In Simpler Way:

Imagine you have a favorite restaurant that you visit frequently. Normally, when you go there, you place your order, and the restaurant serves you promptly.

Now, imagine if a group of people suddenly started bombarding the restaurant with an overwhelming number of orders all at once, non-stop. The restaurant’s staff would be unable to keep up with the sudden surge in orders.

As a result, the restaurant’s resources, such as the chefs, kitchen space, and ingredients, would quickly become overwhelmed and exhausted. They would struggle to process all the incoming orders and serve them in a timely manner.

In this analogy, the restaurant represents a web server or website, and the orders represent HTTP requests made by users’ browsers to access different web pages or resources.

Similarly, in an HTTP flooding attack, the attacker uses a network of compromised computers (botnet) to flood the target server with an enormous number of requests all at once, just like the group bombarding the restaurant with orders.

The server tries to handle each incoming request, but due to the overwhelming volume, its resources become strained. It has to allocate processing power, memory, and bandwidth to handle each request individually.

With limited resources available, the server eventually becomes overloaded, causing a slowdown in its performance. It may struggle to respond to legitimate requests promptly or, in severe cases, become completely unresponsive.

As a result, legitimate users who try to access the website or server may experience significant delays or find the service completely unavailable.

In Technical Way :

Establishing connections: The attacker typically uses a network of compromised computers, known as a botnet, to launch the attack. These compromised computers are often infected with malware that allows the attacker to control them remotely. The attacker instructs the botnet to simultaneously send HTTP requests to the target server.

Crafting HTTP requests: The attacker creates a large number of HTTP requests that appear legitimate, mimicking real user requests. These requests can be either GET or POST requests, commonly used in web applications. Each request contains a specific URL, headers, and sometimes payload data.

Initiating the attack: The botnet starts sending the crafted HTTP requests to the target server. The requests are sent rapidly and continuously, overwhelming the server’s capacity to handle incoming requests. The high volume of requests consumes server resources, preventing it from serving legitimate user requests effectively.

Server response: As the target server receives a flood of requests, it starts processing each request individually. The server needs to allocate resources to handle each request, including establishing a connection, parsing headers, processing the requested resource, and generating a response. The server’s resources become consumed with the flood of requests, making it difficult to handle legitimate traffic.

Resource exhaustion: The continuous influx of requests strains the server’s resources, such as CPU, memory, and network bandwidth. With limited resources available, the server becomes overwhelmed and unable to respond to new requests promptly. As a result, the server’s performance degrades, and it may eventually become unresponsive or crash, denying service to legitimate users.

Impact: The impact of an HTTP flooding attack can vary depending on the target’s infrastructure and defensive measures. In some cases, the server may slow down significantly, causing noticeable delays and degraded performance. In more severe cases, the server may become entirely inaccessible, resulting in a complete denial of service for legitimate users.

Methods of HTTP Flooding

HTTP flooding attacks can be carried out using different methods, each with its own characteristics. Here are some of the commonly employed methods of HTTP flooding attacks:
  • GET Flooding: This method involves flooding the target server with a large number of HTTP GET requests. GET requests are used to retrieve information from a server, such as accessing a web page or fetching a file. By sending an excessive amount of GET requests, the attacker aims to exhaust the server’s resources and overload its capacity to respond to legitimate requests.
  • POST Flooding: Similar to GET flooding, POST flooding involves inundating the server with a massive number of HTTP POST requests. Unlike GET requests, which retrieve information, POST requests are used to send data to the server, often used in forms or data submission. By overwhelming the server with POST requests, the attacker aims to consume server resources required to process and handle each incoming request.
  • Slowloris Attack: The Slowloris attack is a method that exploits the way web servers handle and manage concurrent connections. In this attack, the attacker establishes multiple connections to the target server but sends HTTP requests very slowly, usually in small and incomplete packets. By maintaining these partial connections for an extended period, the attacker consumes the server’s connection slots, preventing legitimate users from establishing connections and effectively causing a denial of service.
  • HTTP POST with Large Payload: In this method, the attacker sends HTTP POST requests with abnormally large payload data. The size of the payload can be several megabytes or even gigabytes. By overwhelming the server with requests containing extensive data, the attacker aims to consume server resources, such as memory or processing power, required to handle and process such large requests. This can lead to server performance degradation or even crashes.
  • HTTP Header Manipulation: HTTP headers contain important information about the request, such as the user agent, content type, or cookies. In this method, the attacker manipulates the HTTP headers of the flood of requests to exploit vulnerabilities in the server’s header parsing mechanisms. By crafting malformed or excessively long headers, the attacker aims to force the server into spending excessive processing time or encountering errors, thereby affecting the server’s performance.
  • Distributed Denial of Service (DDoS): DDoS attacks involve coordinating multiple attacking systems, often forming a botnet, to flood the target server with a massive volume of requests simultaneously. By distributing the attack across multiple sources, DDoS attacks can generate a tremendous amount of traffic, overwhelming the server’s resources and making it extremely difficult to mitigate the attack effectively.

Performing a Basic HTTP Flooding Attack Using Cloud Shell

Disclaimer: The following information is for educational purposes only. Performing an HTTP flood attack on a server without permission is illegal and can result in criminal charges.

To perform a basic HTTP flooding attack using Cloud Shell, you can use a tool called “hping3.” Here’s how to do it:

1. Open Cloud Shell Terminal.

2. Install hping3 by running the following command:

sudo apt-get install hping3


3. In Below Screen Shot This Is my Demo Sever Where I Test This http Flooding Method


Here My Address Is
Target_IP_Address = And Port = 41717

4. Execute the HTTP flood attack by running the following command:

sudo hping3 -S --flood -V -p 41717 TARGET_IP_ADDRESS


  • sudo: gives needed privileges to run hping3.
  • hping3: calls hping3 program.
  • -S: specifies SYN packets.
  • –flood: replies will be ignored and packets will be sent as fast as possible.
  • -V: Verbosity.
  • -p 41717: port 80, you can replace this number for the service you want to attack.

Replace “TARGET_IP_ADDRESS” with the IP address of the target server And -p 80 port No. According To Server Port. This command will send a flood of SYN packets to the target server on port 80, which is the default port for HTTP traffic.

hping3 attack

In The Below ScreenShot You Can See High Traffics Are Comming>.

server Load
Now My Website Is Not Responding Because Of Hight Traffic
Not Response

Why Big Websites Not Down By Http Flooding

Big websites are typically protected by robust infrastructure, including load balancers, DDoS mitigation services, and traffic management systems, which can detect and filter out malicious traffic, effectively mitigating the impact of HTTP flooding attacks.

Tools for Http Flooding:

  • GoldenEye
  • Slowloris
  • LOIC (Low Orbit Ion Cannon)
  • HOIC (High Orbit Ion Cannon)
  • HULK (http Unbearable Load King)
  • Pyloris
  • TOR’s Hammer
  • XOIC
  • RUDY (R U Dead Yet ?)


HTTP flooding is a common and potentially devastating type of DDoS attack. By understanding how it works and the methods used by attackers, you can better protect your web servers and applications from these threats. Always ensure that you have robust security measures in place, such as firewalls, intrusion detection systems, and traffic monitoring, to defend against HTTP flood attacks and other cyber threats.

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