In September 2024 [5] [6] [9], Cloudflare successfully mitigated the largest recorded distributed denial-of-service (DDoS) attack [3] [4] [5] [7] [8] [9], which reached a peak of 3.8 terabits per second (Tbps). This event underscores the critical importance of advanced cybersecurity measures in defending against increasingly sophisticated threats.

## Description

Cloudflare has successfully repelled the largest distributed denial-of-service (DDoS) attack on record [3] [4] [7], which peaked at an unprecedented 3.8 terabits per second (Tbps) during a month-long campaign in September 2024 [5] [7]. This hyper-volumetric attack targeted the Layer 3/4 network layers of various sectors, including financial services [3] [4] [5], telecommunications [3] [4] [5] [6] [9], and internet service providers [2], and involved over one hundred individual attacks designed to overwhelm network infrastructure with excessive data. The largest attack lasted for 65 seconds and aimed to saturate Cloudflare’s systems, primarily utilizing the User Datagram Protocol (UDP) on a fixed port [5].

Throughout this period [6], Cloudflare’s fully autonomous detection and mitigation systems intercepted numerous attacks, many of which exceeded 2 billion packets per second (Bpps) and 3 Tbps [6] [9]. The compromised devices involved in these attacks included MikroTik systems, Asus home routers [3] [7] [9], digital video recorders (DVRs) [3], and web servers [3] [7], with significant contributions from devices exploiting a recently discovered critical vulnerability (CVE 9.8).

Cloudflare’s robust defense systems and global network infrastructure [4], employing an anycast architecture [4], effectively distributed the attack load across multiple data centers worldwide [4], preventing any single point from becoming overwhelmed [4]. This design allowed for the effective management of large-scale attacks without impacting customer performance. The systems utilized real-time dynamic signatures to efficiently identify and block malicious traffic [4], while advanced technologies such as eXpress Data Path (XDP) and extended Berkeley Packet Filter (eBPF) enabled the processing of packets at wire speed with minimal CPU resource consumption [4]. Notably, the mitigation of these attacks was achieved without any human intervention [1], underscoring the necessity of quickly identifying and responding to new attack patterns [7].

Prior to this incident [3] [9], the record for the largest volumetric DDoS attack was held by Microsoft [3], which peaked at 3.47 Tbps against a customer using Azure services in Asia [3]. This incident serves as a critical learning opportunity for organizations aiming to strengthen their cybersecurity measures against future threats [7], highlighting the importance of investing in robust [7], scalable DDoS protection systems and leveraging geographically distributed networks to enhance resilience against evolving DDoS tactics.

## Conclusion

The successful mitigation of this unprecedented DDoS attack by Cloudflare highlights the effectiveness of autonomous, scalable defense systems in protecting against large-scale cyber threats. It emphasizes the need for organizations to invest in advanced cybersecurity infrastructure and adopt a proactive approach to threat detection and response. As cyber threats continue to evolve, leveraging distributed networks and cutting-edge technologies will be crucial in maintaining resilience and safeguarding critical infrastructure.

References

[1] https://www.techspot.com/news/104983-cloudflare-mitigated-38-tbps-ddos-attack-largest-ever.html
[2] https://www.techzine.eu/news/security/125060/cloudflare-blocks-biggest-ddos-attack-ever/
[3] https://www.techmonitor.ai/technology/cybersecurity/cloudflare-reports-mitigation-of-largest-documented-ddos-attack-at-3-8-tbps
[4] https://cybersecuritynews.com/record-breaking-3-8-tbps-ddos-attack/
[5] https://www.techworm.net/2024/10/cloudflare-largest-ever-ddos-attack-3-8tbps.html
[6] https://thehackernews.com/2024/10/cloudflare-thwarts-largest-ever-38-tbps.html
[7] https://cybermagazine.com/articles/cloudflare-lessons-from-halting-the-worlds-biggest-ddos
[8] https://www.fudzilla.com/news/59820-cloudflare-sees-off-world-s-largest-ddos-attack
[9] https://www.techradar.com/pro/security/the-largest-ever-ddos-attack-has-just-been-blocked-heres-how-it-was-done