Explained: How Cloudflare functions and why its outage affected websites

Users reported broken pages and slow loading for websites after many of the world's largest online services, including ChatGPT and X, that depend on Cloudflare for security, were disrupted on November

Cloudflare, the US company that protects millions of websites from malicious attacks, experienced a major global outage on Tuesday, triggering error messages across numerous platforms.

 

Some website owners were unable to access their performance dashboards. Platforms such as X and OpenAI also reported higher outage levels at the same time as Cloudflare’s disruption, data from Downdetector showed.

 

The incident comes less than a month after similar outages at other major cloud service providers, including Amazon’s AWS and Microsoft’s Azure. Alongside Google Cloud, these three companies make up roughly two-thirds of the infrastructure supporting the digital ecosystem.

 

What is Cloudflare?

 

Cloudflare is a global cloud services and cybersecurity provider offering datacentres, website and email security, data loss protection, and defence against cyber threats. It describes its platform as an “immune system for the internet”, deploying technology that sits between clients and external traffic to block billions of threats daily. Its global infrastructure is also used to accelerate internet traffic.

 

The company generates more than $500 million in quarterly revenue from nearly 300,000 customers across 125 countries, including China, The Guardian reported.

 

What triggered the outage?

 

The disruption stemmed from an automatically generated configuration file designed to manage potential security risks, according to a Reuters report. The file became excessively large, overwhelming, and crashed the software responsible for handling traffic across several Cloudflare services. The company said there was “no evidence that this was the result of an attack or caused by malicious activity”.

 

Why it matters

 

Cloudflare has been described as a 'gatekeeper', responsible for monitoring online traffic and defending websites from distributed denial-of-service attacks, in which malicious actors flood servers with requests. It also verifies whether users are human.

 

It is one of a handful of companies that support critical components of the internet’s infrastructure. When its systems fail, websites may effectively go offline, affecting millions of individuals and businesses. ChatGPT and Elon Musk’s X were among the platforms that appeared to be hit by Tuesday’s outage.

 

By some estimates, Cloudflare provides services to one in five websites worldwide.

 

Previous outages

 

Cloudflare’s systems have suffered multiple outages in recent years. In July 2019, a software bug caused one part of its network to consume excessive computing resources, forcing thousands of websites that rely on Cloudflare offline for up to 30 minutes. During that disruption, services such as Medium, Discord, Shopify Inc, and Dropbox Inc were affected.

 

In June 2022, the company experienced another outage that hit traffic in 19 datacentres managing a substantial portion of its global load, again taking several major websites and services offline.

 

Cybersecurity experts have repeatedly warned about the risks of relying on a small cluster of companies to keep the global internet functioning. Some caution that this has created a “dependency chain”, leaving internet infrastructure vulnerable when any major provider falters.