What is the slowloris attack?

Overview

Slowloris is a DoSDenial of service:It is an attack to shut down a system, making it inaccessible to its users. attack that allows a hacker to overwhelm the target server using numerous simultaneous HTTP Hypertext Transfer Protocol is the internet protocol used to transfer data over the web.connections.

Slowloris uses these restricted HTTP requests to open connections between a single computer and the target web server. It keeps those connections as open as possible to overwhelm the target and slow down the application layer. This DoS attack requires minimal bandwidth to boot and affects only the target web server and no other services or ports.

Given below is an example of the stated attack.

An illustration of how a slowloris attack works

How does it work

Slowloris is not an attack category but a specific attack tool designed to allow a single machine to shut down a server without much bandwidth. Unlike reflection-based DoSIt is a type of DoS attack that allows hackers to magnify the amount of malicious traffic they can generate. attacks, which consumes a lot of bandwidth, such as NTP amplificationIt is a DoS attack that relies on the use of publicly accessible NTP servers to overwhelm a victim system with UDP traffic., this attack uses low bandwidth. Instead, it intends to consume server resources in requests that appear slower than expected but mimic regular traffic.

The target server has only enough threads to handle concurrent connections. Each server thread tries to stay alive while waiting for the slow request to complete, but this never happens. If the maximum possible link on the server exceeds, it will not respond to further connections, and a denial of service will occur.

Example

DoS attacks are carried out for a variety of reasons. For a long time, the online gaming sector has been a frequent victim of DoS assaults. DoS for hire services also attack a competitor's website to bring it down.

Political motives are sometimes the motivations for assaults. Georgia and Estonia, targeted in 2007, are good instances of this. In addition, Russian nationalists used a traffic overload to bring down all media and government websites to protest the removal of a soviet battle memorial.

Steps

Here are some defined steps in how the attack works:

  1. The attacker first sends various partial HTTP request headers to open multiple connections to the target server.
  2. The target creates a thread for each incoming request to close the line once the connection establishes—when and if the relationship takes too long. The server times out an excessively long connection for efficiency and frees threads for subsequent requests.
  3. To ensure the target does not time out of the connection, the hacker periodically sends a partial request header to the target to keep the request alive.
  4. The target server cannot open partial connections while waiting for the request to complete. When no threads are available, the server will not be able to respond to additional recommendations from regular traffic, resulting in a denial of service.

Prevention

There are several ways to mitigate the impact on web servers vulnerable to this attack. Here are some of them:

  • Having a higher server availability: Increasing the maximum number of clients allowed by a server while increasing the number of connections an attacker must make before the server is compromised can be overloaded.
  • Inbound request rate limits: Methods such as limiting the maximum number of connections that a single IP address can establish and limiting slow transfer rates are approaches for determining the effectiveness of attacks like Slowloris.
  • Use cloud-based protection: Use a service that can act as a reverse proxy and protect your origin server.
  • Adopt DoS protection services: This allows enterprises to implement comprehensive cybersecurity strategies and security measures. These measures would be beyond individual countermeasures and provide complete security solutions against cyberattacks, such as Slowloris.

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