Application Layer (OSI Layer 7) DDoS Attack?

Did you know that application layer attacks are one of the most common types of DDoS attacks? In fact, they account for nearly 60% of all DDoS attacks! While these attacks can be complex, they typically target a specific aspect of an organization's website or online service. By bringing down this critical component, attackers can cause serious disruptions and downtime.

DDoS Attack Activity

What are Layer 7 DDoS Attacks?

Application layer DDoS attacks, also known as Layer 7 DDoS attacks, are dangerous and sophisticated tools used to attack user-facing applications and networks. These malicious attacks target application layer protocols such as HTTP and DNS, often with the intention of disrupting services or hijacking application protocols. Because application layer attacks focus on the application layer, they can go undetected by traditional defense systems while still taking down websites or networks. Common attack techniques include request floods, application vulnerability exploitation, application-specific attacks such as XML-RPC floods, and zero-day vulnerability exploitation. Protecting user facing applications or networks from these application layer attacks should be a priority for any organization looking to stay secure in the digital space!

Application Layer 7 DDoS Attack

How do application layer attacks work?

Application Layer attacks are a type of Distributed Denial of Service (DDoS) attack that targets application-layer services such as web servers and application firewalls. Such an attack can lead to website service disruption, or even complete website shutdown. An application layer attack takes advantage of the communication protocols used to exchange data between two applications running over the internet. It generally requires fewer resources to mount a successful application layer attack compared to other DDoS attack types since it causes more damage due to its customized nature aimed at specific services or protocols for example HTTP, SMTP or FTP. This makes application layer attacks a common tactic for disrupting critical services, and firms that are serious about protecting their online presence should invest in robust application layer threat mitigation solutions.

What are the different types of Application Layer DDoS Attacks

Application Layer (Layer 7) DDoS Attacks have become an increasingly important concern for businesses, as they can easily overload application servers and cause services to be unavailable. They are more difficult to detect than other DDoS attack types since application layer attacks mimic real user behavior and blend in with regular application use. These attacks can range from subtle application slowdown to full application shut down and come in many forms, such as

All of these different kinds of application layer 7 DDoS attacks can have devastating impacts on system availability if preventive measures are not taken, so it is important for businesses to be aware of the various attack types and how they may affect operations.

Layer 7 DDoS Attack Mitigation

Protecting your website or application from a DDoS attack is an increasingly important need in today’s digital world. Layer 7 DDoS attacks are particularly damaging because they target the application layer of your website with malicious requests to overwhelm your servers and cause a denial of service or disruption. There are several steps organizations can take to mitigate against Layer 7 attacks:

  • Increase webserver connection limits: This can help reduce vulnerability to connection-based attacks such as Slowloris since it reduces the maximum number of open connections that an attacker needs to maintain control over resources on the target webserver.
  • Implement rate limiting: Rate limiting involves restricting incoming requests from any given IP address in order to prevent DDoS attacks such as those launched by Slowloris attackers. It is essential for organizations to regularly monitor their networks for traffic abnormalities that could indicate malicious activity and take immediate action if necessary.
  • Use load balancers and web application firewalls (WAFs): WAFs help protect against application layer DDoS attacks by identifying and blocking malicious traffic before it reaches your network or applications. They also provide logs which organizations can review to identify any potential threats or anomalies quickly and act accordingly. Load balancers and reverse proxies can buffer connection and implement multiple connection management techniques to prevent incomplete HTTP requests from affecting application and web servers.
  • Organizations should also consider using services such as cloud-based DDoS protection or botnet tracking solutions in order to identify suspicious activity quickly and respond appropriately.
  • Additionally, security best practices such as keeping software updated and patching vulnerabilities regularly should be followed in order to minimize risk and protect against all types of threats, including those posed by malicious actors who use techniques like Slowloris DDoS attacks.
  • Radware DDoS protection (DefensePro, Cloud DDoS Protection Service), WAF (AppWall and Cloud WAF) and application delivery (Alteon with integrated WAF) solutions mitigate application layer (layer 7) attacks by using approaches that block attacks without impacting legitimate traffic. By using machine-learning and behavioral-based algorithms, Radware can understand what constitutes a legitimate behavior profile and then automatically block malicious attacks, while managing user connections effectively without impacting legitimate HTTP requests. This increases protection accuracy while minimizing false positives and disruption to legitimate users.

What to do under an Application Layer (Layer 7) DDoS Attack

A DDoS attack on your website or application can be a serious disruption, compromising the stability and performance of the system, leading to downtime and impacting user experience. If you detect an Application Layer (Layer 7) attack is affecting your website or application it is essential to take action quickly to limit the effect of the attack. An initial response includes taking the system offline if needed to prevent further disruption, using security systems such as WAFs (Web Application Firewalls) to help mitigate attacks, and seeking technical advice from experts in DDoS protection and online security. Being proactive with strong security configuration and methods can also help deflect potential malicious attacks. Taking these steps will help protect your website or application while restoring normal levels of service in a timely manner.


Application layer or Layer 7 DDoS attacks are among the most sophisticated and powerful types of attacks that can be launched against a website or application. These attacks work by overwhelming the target with requests that appear to come from genuine users, thereby preventing legitimate traffic from getting through. There are several different types of application layer attacks, each of which has its own unique characteristics. Radware's behavioral-based detection engine is able to detect and defend against all known types of application layer attacks. Contact Radware today for best-in-class protection against DDoS attacks of all kinds.

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