From thehackernews.com
![cdn cache poisoning dos attack](https://1.bp.blogspot.com/-VpIzIXnr6Nc/XbAJseFx07I/AAAAAAAA1ec/Qnh5aiPdiCQlHbBgTV9PXYNq9lXX5-VhwCLcBGAsYHQ/s728-e100/cdn-cache-poisoning-dos-attack.png)
A team of German cybersecurity researchers has discovered a new cache poisoning attack against web caching systems that could be used by an attacker to force a targeted website into delivering error pages to most of its visitors instead of legitimate content or resources.
The issue affects reverse proxy cache systems like Varnish and some widely-used Content Distribution Networks (CDNs) services, including Amazon CloudFront, Cloudflare, Fastly, Akamai, and CDN77.
In brief, a Content Distribution Network (CDN) is a geographically distributed group of servers that sit between the origin server of a website and its visitors to optimize the performance of the website.