Proxies are absolutely crucial to the operation of the internet, but they also represent a clear and present danger to users. Finding that balance is pretty much a full-time job for cybersecurity. The recent Amazon Web Services (AWS) and Microsoft Azure outages are good examples of that.
Amazon explained the outage was caused by “failing intermediaries” monitoring system health, preventing proper traffic routing. Another word for intermediaries is “proxies”. When the monitoring subsystem malfunctioned, health check updates were not propagated properly, causing backend servers to appear offline even when they were active, which invalidated DNS lookups. This created a cascading failure.
Likewise, the Azure outage was caused by a misconfiguration of the proxy Front Door, a global entry point for content delivery network functionality, load balancing, and application acceleration.
How Proxies Function
When a user wants to access a website, the request goes to the proxy server instead of going directly to the internet. The proxy server receives the request, then forwards it to the target website. It modifies the request header to hide the user's original IP address.
