The Chronic Dev Team has released the greenpois0n untethered jailbreak for iOS 4.2.1. It took an extra 48 hours for the jailbreak to be released for those using Windows systems (meaning, most of us), but that's now here as well.
Pangu for Mac Released : For iOS 7.1 and iOS 7.1.1
Download it and enjoy iOS jailbreak in your MAC system.
Don't miss to use in your apple device (Most of apple device are supported).