3gs jailbreak 4.2.1 out the box?

[vietkool]

Friend of mine just got the 3Gs from the $49 deal at AT$T. The fone running 4.2.1, firmware 05.15.04. He is with AT$T and he just want to jb the fone only ( no unlocked needed). can his phone be able to jb ?

thanks

[Tokioh]

GreenPois0n
Enjoy.

[vietkool]

Can I use pwnage tool to do it? and after jb, can he still using at$t SIM card for his phone?

[Tokioh]

From what i have seen yes. See- Dev-Team Blog

[wildmanviper]

Tiny Umbrella for shsh blobs and GreenPoison