Why is it hard to come up with untethered jailbreak

Why they can get a tethered jailbreak but not untethered. Is there any reason to that. Just wanna understand the process thx

An untethered jailbreak requires additional security weaknesses to be found.   They are both hard to find, and used sparingly (to make sure that Apple does not promptly patch them) by the jailbreaking community.



Would it be possible that the security features that were breched in 5.2, 5.1.1,5.1,5.0.2, 5.0.1, etc be applied to the tethered jailbreaks of 5.0, 4.4.2, 4.4.1, or 4.4 so that anyone on those can get untethered? or is the firmware completly re-written each time and that would be too much trouble?

I have no idea of the details, but in my experience when new firmware is released then jailbreaks for earlier firmware releases do not get revisited.


O.K. I always wondered about that.