There are a large number of Cloudflare's services and websites that use parsing HTML pages and modify them through the Cloudflare's edge servers.
Even if you do not use Cloud Flare directly, that does not mean that you are spared.
Users on YCombinator have confirmed the presence of HTTP header data for apps like Discord, Fit Bit, and Uber by searching through Duck Duck Go caches with targeted search terms.
In an analysis conducted by Now Secure, the researchers have discovered some 200 i OS apps that identified as using Cloudflare services from a sampling of some 3,500 of the most popular apps on the app store.
Following Ormandy's public disclosure of the vulnerability on Thursday, Cloud Flare confirmed the flaw, ensuring its customers that their SSL private keys were not leaked.