How we built rate limiting capable of scaling to millions of domains

Published on by Julien Desgats.

Back in April we announced Rate Limiting of requests for every Cloudflare customer. Being able to rate limit at the edge of the network has many advantages: it’s easier for customers to set up and operate, their origin servers are not bothered by excessive traffic or layer 7 attacks,

IoT Security Anti-Patterns

Published on by Junade Ali.

From security cameras to traffic lights, an increasing amount of appliances we interact with on a daily basis are internet connected. A device can be considered IoT-enabled when the functionality offered by its Embedded System is exposed through an internet connected API. Internet-of-Things technologies inherit many attack vectors that appear

Introducing TLS with Client Authentication

Published on by Dani Grant.

In a traditional TLS handshake, the client authenticates the server, and the server doesn’t know too much about the client. However, starting now, Cloudflare is offering enterprise customers TLS with client authentication, meaning that the server additionally authenticates that the client connecting to it is authorized to connect. TLS

AES-CBC is going the way of the dodo

Published on by Vlad Krasnov.

A little over a year ago, Nick Sullivan talked about the beginning of the end for AES-CBC cipher suites, following a plethora of attacks on this cipher mode. Today we can safely confirm that this prediction is coming true, as for the first time ever the share of AES-CBC cipher

Understanding Our Cache and the Web Cache Deception Attack

Published on by Joshua Liebow-Feeser.

About a month ago, security researcher Omer Gil published the details of an attack that he calls the Web Cache Deception attack. It works against sites that sit behind a reverse proxy (like Cloudflare) and are misconfigured in a particular way. Unfortunately, the definition of "misconfigured" for the purposes of