If you still haven’t jailbroken your iDevice, now it’s the time to do it before it’s too late – because after iOS 6.1.3 comes out, you won’t be able to do it. One of the creator of the Evasion jailbreak for iOS 6, David Wang or mostly known as Planetbeing, told Forbes that Apple has fixed one out of the five exploits used in order for evasi0n to jailbreak your device. The hacker says that if one out of the five exploits doesn’t work, then the evasi0n jailbreaking tool will not work at all.
“If one of the vulnerabilities doesn’t work, evasi0n doesn’t work,” he says. “We could replace that part with a different vulnerability, but [Apple] will probably fix most if not all of the bugs we’ve used when 6.1.3 comes out.”
So once Apple release iOS 6.1.3, don’t update to it unless you know how to downgrade your device using the SHSH blobs if possible.
[Forbes]