well
if you don't want to Jailbreak or unlock yes it's safe!
Wish this could be my signature I used it enough!
Source the one and Only Dev-Team!
On Tuesday, Apple released firmware 3.1.3 for the iPhone and iPod touches. Unless youve personally observed a problem with the reporting of your battery percentage, theres no reason to update to 3.1.3. We know some of you will want to anyway. Superbowl Sundays PwnageTool 3.1.5 for Mac OS X will let you do so safely, preserving your jailbreak and ultrasn0w unlock. (If you use the blacksn0w unlock (at baseband 05.11.07), you need to stay at 3.1.2.)
iPhone 3G and 3GS unlockers should always be very wary to update their firmware. This is no exception. If you make a mistake along the way you may find yourself updating to official 3.1.3 in which case you will lose your unlock, possibly forever.
iPhone 3GS users (regardless of unlock) should stay away from this and all 3.1.3 jailbreak tools unless you know you have your SHSH hashes backed up via Cydia. Thats because if you make a mistake you may find yourself stuck at official 3.1.3 with no way to jailbreak or come back down to 3.1.2 to jailbreak.
If you really truly feel that you need to update, this version creates a custom 3.1.3 IPSW for you to restore to on your iPhone 2G, iPhone 3G, iPhone 3GS with early bootrom, iPod touch 1G, and iPod touch 2G with early bootrom. If you dont know if you have an early bootrom or not, please avoid updating until you learn more.
You dont need to be pre-jailbroken on anything but the iPod touch 2G early bootrom. And really for that device, its faster and easier to use redsn0w 0.9.4 as mentioned in our last post. For that matter, if you have an ipt1g, iphone2g, or iphone3g(and dont need an unlock), you should use redsn0w too (but version 0.9.3). Its faster and you wont have to go through a full restore process (just do an update then run redsn0w, pointing it at 3.1.2 FW instead of 3.1.3).
If you have an iPhone 3GS: PwnageTool works if youre currently at version 3.1.2 or below (down to 3.0) and if you know you have a old bootrom. You dont need to be already jailbroken PwnageTool will ask you if youre jailbroken after youve created the IPSW. Dont use PwnageTool unless you know for sure you have an old bootrom (if youre not sure, assume the worst and dont use it). Dont use PwnageTool on the iPhone 3GS if youre at 3.1.3, it just wont work. Downgrade to 3.1.2 using the methods described here. If you cant downgrade because you dont have your 3GS 3.1.2 hashes on file with Cydia, youll need to sit out the 3.1.3 jailbreak.
We arent revealing any new exploits to Apple with this jailbreak. Everything here has been used before, its just a straightforward port of Pwnage2 and 24Kpwn to the new firmware. Its possible the new firmware was released largely to flush out new exploits before the next big release. We wont be biting.
Wed really like the above warnings and disclaimers to sink in. Please dont download the files below and use them blindly.
Please feel free to ask any questions in the comment section below. Weve got a bunch of expert help there, including our friendly moderators confucious and angie!
George Hotz advice is Simpler!
Don't do it if you do your a fool!