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Understanding Slowloris Attack

· 4 min read

slowloris

In today's digital landscape, where cybersecurity threats continue to evolve, it is crucial for organizations to be aware of different attack vectors and employ effective security measures. One such attack that can cripple web servers is the Slowloris attack. In this blog post, we will delve into what Slowloris is, its attack description, various mitigation techniques, and how PowerWAF can be a robust defense against this specific type of attack.

What is Slowloris Attack?

Slowloris is a malicious application layer DDoS attack that targets web servers by exploiting the connection pool limit. It keeps multiple connections open from a single source using partial and slow HTTP requests, overwhelming server resources and causing slowdown or unavailability.

What is Slowloris?

Slowloris is a type of Denial of Service (DoS) attack designed to exploit the limited resources of a web server by keeping multiple connections open for as long as possible. Unlike traditional flooding attacks that overwhelm a server by sending a high volume of requests, Slowloris works by sending a steady stream of incomplete HTTP requests, thereby tying up server resources such as connections, threads, and memory.

Description of the Attack

Slowloris targets the fundamental design of web servers, which allocate a certain number of resources for each incoming connection. By exploiting this design, the attacker initiates a large number of connections to the server, but deliberately sends incomplete request headers, keeping the connections open indefinitely. As a result, the server resources become exhausted, causing legitimate users to experience slow response times or even complete service unavailability.

Mitigation Techniques

To safeguard against Slowloris attacks, organizations must implement effective mitigation techniques that enhance their server's resilience. Here are some recommended practices:

  • Increase Server Capacity: By scaling up server resources such as connections, threads, and memory, organizations can accommodate a higher number of simultaneous connections and mitigate the impact of Slowloris attacks.

  • Set Connection Timeout Thresholds: Configuring appropriate connection timeout thresholds ensures that connections that do not complete within a specific time limit are terminated, preventing resource depletion caused by prolonged open connections.

  • Implement Rate Limiting: By imposing limits on the number of connections from a single IP address or rate of requests from individual clients, organizations can restrict the effectiveness of Slowloris attacks. This prevents a single attacker from exhausting server resources.

  • Web Application Firewalls (WAF): Deploying a robust WAF solution like PowerWAF can significantly strengthen your defenses against Slowloris attacks. PowerWAF leverages advanced algorithms and heuristics to detect Slowloris attack patterns in real-time, identifying malicious traffic and blocking it before it reaches the server.

How PowerWAF helps against Slowloris attacks

PowerWAF acts as a proactive shield against Slowloris attacks, offering comprehensive protection to web servers. It employs a combination of signature-based detection, behavioral analysis, and machine learning algorithms to identify the distinctive patterns exhibited by Slowloris attacks. By analyzing the traffic in real-time, PowerWAF can detect and block suspicious connections, minimizing the impact of such attacks on server performance.

Furthermore, PowerWAF provides granular control over request limits, allowing administrators to fine-tune protection parameters and customize rate limiting rules based on their specific requirements. This flexibility ensures that legitimate users experience uninterrupted service while effectively stopping Slowloris attacks.

Conclusion

Understanding the Slowloris attack and implementing effective mitigation strategies are critical steps in safeguarding web servers from this particular threat. By employing best practices such as scaling server resources, setting connection timeouts, and implementing rate limiting, organizations can enhance their resilience against Slowloris attacks. Additionally, by integrating PowerWAF as a defense mechanism, organizations can benefit from its advanced detection capabilities and customizable protection rules, providing a comprehensive shield against this disruptive attack vector. Stay protected with PowerWAF and ensure the uninterrupted availability and performance of your web applications.

More Information

If you want more information about the attacks on the TCP/IP protocol, like DDoS attacks or Slowloris attack, see our Learning Center with many articles about this topic.

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