Security

Content Delivery Networks, or CDNs, are now invisible yet essential infrastructure. They accelerate websites, deliver video, block attacks, and connect billions of users to online services. Their story stretches from the late 1990s, when a few pioneering companies sold premium acceleration to media giants, to today, when free CDN tiers are available to anyone running a blog. This article traces that history, highlighting the technical and commercial shifts that shaped the CDN industry. ...

Content Delivery Networks, or CDNs, keep much of the modern web running smoothly. They are behind faster page loads, fewer outages, and safer browsing experiences. If you have wondered how they work or whether you should use one, here are the ten questions people ask most - with answers in plain language. For more advanced strategies that combine multiple providers, see the Top 10 Questions About Multi-CDN. 1. What is a CDN and how does it work? A CDN is a network of servers in many locations. It stores copies of website content on those servers so they can be delivered from a place closer to the visitor. Instead of every request going back to the main origin server, a CDN routes the visitor to the nearest edge server. The shorter the journey, the faster the response. ...

On August 13, 2025, the CERT Coordination Center updated its MadeYouReset vulnerability note. The note describes an HTTP/2 implementation flaw tracked as CVE-2025-8671. A client can trigger server-sent stream resets while backend work continues, which can exhaust server resources. CERT/CC listed Cloudflare as notified on May 28, 2025, but marked its response status as unknown in the August update. The available record therefore did not support the original article’s claim that Cloudflare had deployed a specific global mitigation. ...

Synopsis An origin that serves multiple CDNs must tolerate their combined fetch patterns and different failure behavior. Topology, shielding, authentication, cache keys, deployment order, and failover controls determine whether content remains correct when traffic moves. Role of the origin in multi-CDN The origin is the source of truth for content and APIs. In a multi-CDN setup more than one provider will fetch from it. The design must handle higher fan in, different retry behaviors, and different cache semantics without breaking correctness. It should also keep the number of variables low so that problems are diagnosable during incidents. ...

Synopsis Security controls need equivalent outcomes when more than one CDN serves a property. Policy ownership, web application firewall rules, bot defenses, rate limits, origin authentication, secrets, drift control, verification, log normalization, and incident procedures all affect that parity. A routing change must not silently change the security policy. Scope and objectives Security parity means that requests receive the same protection and the same outcomes independent of provider. Rules must be functionally equivalent, telemetry must be comparable, and emergency controls must have the same effect at all edges. Differences in vendor features are handled by choosing portable constructs first and by documenting exceptions that cannot be avoided. ...

Synopsis Transport security across CDNs depends on a coordinated certificate lifecycle, subject names, revocation signals, transparency monitoring, and origin authentication. Automation must account for different session behavior and provider controls without creating a service gap during rotation. Scope and goals The transport layer must present a uniform and reliable interface regardless of which CDN serves a connection. Users should see correct certificates, modern protocol support, stable cipher policy, and predictable session behavior. Operations should see an automated lifecycle that avoids expirations, supports rapid revocation, and provides clear observability. The origin path should authenticate CDNs in a way that cannot be replayed from the public internet. ...