Update: Ultrasn0w is now officially updated to unlock iOS 4.3.2. Follow this guide instead: How to unlock iOS 4.3.2 using Ultrasn0w (old basebands)

A new version of ultrasn0w, the iPhone unlocking tool, has been released by a developer known as ‘DjayB6’ that unlocks iPhone 3GS and iPhone 4 on iOS 4.3.2 on specific basebands. Following are the complete instructions and step by step guide to unlock iOS 4.3.2 using ultrasn0w.

Before you go for this unlock, you must know:

- If you update to the stock iOS 4.3.2, your device’s baseband also get updated that makes it unable to be unlocked (so far) so do not update to stock iOS 4.3.2 if you rely on factory unlocked iPhone.

- Ultrasn0w Fixer for 4.3.2 unlocks the devices on the following basebands.
01.59.00
04.26.08 
05.11.07
05.12.01
05.13.04
06.15.00

- Ultrasn0w Fixer for 4.3.2 does not unlock the devices on the following basebands.
02.10.04
03.10.01
04.10.01
05.14.02
05.15.04
05.16.02

So please first make sure that your iPhone is on the baseband that is supported by ultrasn0w.

- If you are an iPhone 3GS user, you need to update to iPad’s 06.15.00 baseband to use this unlock. You can use Redsn0w to do this by jailbreaking iOS 4.1 or 4.2.1 before proceeding. WARNING: Your GPS might stop working after doing this. It’s on your own risk.

- I will not be responsible if anything bad happens with your iPhone, you follow this guide on your own risk. Please read the instructions very carefully before attempting this tutorial.

How to unlock

1) Jailbreak your iPhone to iOS 4.3.2 by the following guides:

- How to jailbreak iOS 4.3.2 using Redsn0w 0.9.6rc14
- How to jailbreak iOS 4.3.2 on windows using Sn0wbreeze 2.6 

2) Run Cydia on your jailbroken iPhone and go to Manage > Sources.

3) Tap edit and then tap add. In URL, add ‘http://djayb6.com’ and tap Add Source.

4) Wait while Cydia adds the resources and reloads the data.

5) When the installation is done, search for ‘ultrasn0w fixer for 4.3.2’ and install the application. This will unlock your device.

[via RedmondPie]