What is Session Flood?

Session Flood: How Cyber Attacks Disrupt Service and Drain Resources with Massive Connection Requests

Session Flood in the context of cybersecurity is a type of attack pattern where the attacker overwhelms a system's session handling capabilities by sending large number of requests thus causing the system to slow down, crash or even become unresponsive. It is not a brute force attack where the attacker attempts to gain unauthorized access to information, rather it seeks to compromise the system's availability making it difficult, if not impossible, for legitimate users to use the system.

Consider a retail website that a multitude of customers rely upon for making everyday purchases. Typically, every time a customer logs onto this website, they create a 'session' which allows the website to keep track of the customer's activities. Some information associated with these sessions, such as the customer's identification (ID), products viewed, items put in cart and so on, might even be stored for future reference. Now imagine an attacker intentionally creating a multitude of such sessions rapidly. The record of these sessions goes to fill up the server's memory quickly, denying service to legitimate users who might not be able to create sessions anymore. This is essentially what session flooding intends to achieve.

Session flooding attacks are, thus, rightly categorised under Denial of Service (DoS) attacks. These DoS attacks could have variations like Distributed Denial of Service (DDoS) attacks where the flood of traffic originates from multiple locations, making it even more challenging to control and shield against them.

Interestingly, it does not take sophisticated technical skills or resources to carry out a session flooding attack, making it popular among cybercriminals, consequently, making it a significant threat in the cyberspace. Perpetrators ranging from individual hackers to large scale cyber criminals can easily launch this attack on websites or systems.

Defending against such attacks is not a straightforward task. One prevalent approach is to limit the number of sessions per user. This can be done by setting up an upper limit to the number of sessions one IP address can initiate. By establishing the limits on the number of sessions per IP address, it can possibly obstruct a session flooding attack. Though, this methodology may lead to blocking legitimate sessions, potentially causing inconvenience to users. given the use of bots and multiple IPs in DDoS attacks, this approach alone is largely not effective.

A more comprehensive solution is to employ multifaceted technologies focusing on detection, mitigation, and prevention. This includes utilizing network behavior analysis tools to detect unusual activity like a sudden surge in sessions, followed by intrusion detection mechanisms to provide alerts in real-time. These tools' configurations would necessitate the insights into the web server's usual patterns to differentiate between the normal and the unusual effectively.

Antivirus software and firewalls are necessary as well, as they can detect known threat signatures and alert the user or block the suspicious traffic. The function of an antivirus software in the prevention of these attacks starts from inspecting files or codes for viruses and ends at blocking or fixing the infected software.

Despite the grim picture painted by the onset of these attacks, comprehensive, ongoing cybersecurity strategies coupled with the advancements in technology are making it increasingly difficult for such attacks to be successful. An effective blend of traditional controls such as firewalls and antivirus, coupled with new-age AI-based detection mechanisms and sound policies and practice, can go a long way in mitigating session flooding attacks.

Cybersecurity, as a field, continuously evolves and metamorphoses to meet the requirements of the technological advancements and the associated risks. In this continuous run, tackling new and evolving cyber threats, whilst ensuring business continuity and semi-smooth operation is the real challenge for organisations worldwide. striking the correct balance between adequate protection and business functionality proves that organisations are ready to face the growing risk and threat of cyber-attacks, session floods included.

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