If that is indeed the case, this would make an iOS 7.1 untethered jailbreak impossible at least for the foreseeable future. Its no secret that developers now have a hard time in finding exploits, since they now have to scour the software for vulnerabilities instead of simply using a hardware based exploit. Well known jailbreak developer iH8sn0w has tweeted that while the code sign bug used by evasi0n iOS 7 jailbreak still exists, Apple seems to have patched the kernel exploit in iOS 7.1 beta 4. Apple is unlikely to reverse the change when iOS 7.1 is publicly released, so if the firmware drops in the next couple of weeks, it would be best if you don’t upgrade to it right away, or else you might lose jailbreak on your device for a long time.