Cloudflare CDN Bug Outs User Locations on Signal, Discord

A flaw in the widely used Cloudflare content delivery network (CDN) can expose someone's location by sending them an image on platforms like Signal and Discord, deanonymizing them in seconds without their knowledge. That's according to a 15-year-old security researcher who goes by only "Daniel," who published research on GitHub Gist about the flaw — which he discovered three months ago — as a warning for journalists, activists, and hackers, who could be at physical risk. The flaw allows an attacker to grab the location of any target within a 250-mile radius when a vulnerable app is installed on a target's phone, or even as a background application on their laptop. Using either a one-click or zero-click approach, an attacker can use the app to "send a malicious payload and deanonymize you within seconds — and you wouldn't even know," Daniel wrote. The core of the flaw lies in one of Cloudflare's most used features: caching, Daniel explained. Cloudflare's cache stores copies of frequently accessed content, such as images, videos, or webpages, in its datacenters, ostensibly to reduce server load and improve website performance. When a device sends a request for a resource that can be cached, Cloudflare retrieves the resource from its local data center storage, if possible, or from the origin server. It then caches it locally, and returns it. "By default, some file extensions are automatically cached but site operators can also configure new cache rules," Daniel explained. Becaus...