Streamline: custom video pipelines with Cloudflare Stream and Workers

Cloudflare Stream is a powerful broadcasting platform that, for many of our customers, just works. But what if you wanted to render dynamic annotations on a livestream or create an alternate version of a hosted video with burned-in subtitles? You would need to run a custom video pipeline.

Today, we’re releasing a new developer playground, Streamline, that demonstrates how you can build a system to deliver these bespoke video experiences on Cloudflare’s Developer Platform. We’ll walk you through how Streamline leverages Workers, Containers, and several media protocols to modify video — and immediately publish that output as livestream or new hosted video. You’ll also have the opportunity to try it for your projects.

A processing pipeline needs a durable, long-running environment that can run specialized, compiled code with predictable memory and CPU capacity. Video streams can run for minutes or hours, so the media process needs a lifecycle independent of the request that started it. An application should be able to start a pipeline, send its input, inspect it, and stop it without needing to keep a single request open for the entire duration.

Cloudflare provides the primitives we need. Containers are long-lived runtimes suitable for media processing. Durable Objects Continue reading

Uncovering the Hidden WebP vulnerability: a tale of a CVE with much bigger implications than it originally seemed

At Cloudflare, we're constantly vigilant when it comes to identifying vulnerabilities that could potentially affect the Internet ecosystem. Recently, on September 12, 2023, Google announced a security issue in Google Chrome, titled "Heap buffer overflow in WebP in Google Chrome," which caught our attention. Initially, it seemed like just another bug in the popular web browser. However, what we discovered was far more significant and had implications that extended well beyond Chrome.

Impact much wider than suggested

The vulnerability, tracked under CVE-2023-4863, was described as a heap buffer overflow in WebP within Google Chrome. While this description might lead one to believe that it's a problem confined solely to Chrome, the reality was quite different. It turned out to be a bug deeply rooted in the libwebp library, which is not only used by Chrome but by virtually every application that handles WebP images.

Digging deeper, this vulnerability was in fact first reported in an earlier CVE from Apple, CVE-2023-41064, although the connection was not immediately obvious. In early September, Citizen Lab, a research lab based out of the University of Toronto, reported on an apparent exploit that was being used to attempt to install spyware on the iPhone Continue reading