Due to a mistake on Apple’s servers, there was a short moment when users could downgrade to older versions of iOS. The list of signed iOS versions on the IPSW.me website included signed versions of iOS 11 to iOS 6.
Apple recently issued a patch for the vulnerabilities named Meltdown and Spectre, that have been found in the Intel processors. The patch should have been installed on every device that received the update, but there’s a pitfall. Despite Apple assured customers the fix won’t slow down the devices, it actually did.