iPhone Firmware 1.1.3 Jailbreak Goes Public

An iPhone dev Team splinter group has released the 1.1.3 jailbreak.The jailbreak is available for both Mac and Windows users. This update comes in the form of an "soft upgrade" so you must have a jailbroken 1.1.1 or 1.1.2 phone before you begin. A special edition of Nate True's iBrickr software will prepare the disk image for the update and a second installer portion will flash the phone. Smxy repository maintainer, Shawn Erickson has packed up the second portion of the jailbreak, which will be available on installer.app.

This is not a full jailbreak as much as it is upgrade process. This soft upgrade allows full use and functionality of firmware 1.1.3 without the dev team exposing its vulnerabilities. Their strategy is to keep another jailbreak in reserve if and when Apple patches this exploit with the SDK.

A distinction of this jailbreak is that you will not have to upgrade your baseband -- but google locations will not work unless you do. However, if you don't plan to unlock your phone. You can choose to upgrade your baseband. The easiest way to do this is to upgrade to 1.1.3 using iTunes and then downgrading your firmware for jailbreak/activation using this Guide.

One very significant consideration on upgrading your baseband then downgrading your firmware. Firmware downgrades are limited to phones with bootloader 3.9. iPhones with bootloader 4.6 allow you to downgrade the firmware but not the baseband. Not sure, and still interested? Check your bootloader!

What is a bootloader? Bootloader is the iPhone program that loads up the operating system. Apple has released several versions of the bootloader. Unlocks have been limited to what version of bootloader you have been running on your system. Firmware 1.0.2 - 1.1.1 shipped with bootloader 3.9. The newer phones ship with 4.6. You can check which version of bootloader you are running here.
As a rule, this does not matter - unless you want to or need to unlock your phone in the future.

See you on the other side!