This is just a quick heads up : Saurik has a Mobilesubstrate update up his sleeve which fixes ASLR issues in iOS 4.3, which was not officially pushed in Cydia. We don’t know if this update will fix all ASLR issues on iOS 4.3 and Mobilesubstrate issues and how buggy this Mobilesubstrate update is, but my initial testing shows that this is what you need if you are on a jailbroken iOS 4.3 iDevice to fix ASLR issues. The following step by step guide will help you fix ASLR issues in Cydia after jailbreaking your iPhone, iPad or iPod touch on iOS 4.3.



For those of you who don’t know, Apple implemented ASLR (Address Space Layout Randomization) in iOS 4.3 to make iOS devices more secure against vulnerabilities. This ASLR implementation breaks Mobilesubstrate which is required for many Cydia tweaks like Winterboard.

Fix ASLR Issues On Jailbroken iOS 4.3 [How To] :

1) Start Cydia > install Safari Download Manager and iFile for your version of iOS device. You can get full version of iFile from our Repo here.



2) Now navigate to this link via Safari browser on your iPhone, iPad or iPod touch.

3) Download the .deb file to : /var/mobile directory as shown in the screenshot below.

4) Now start iFile and navigate to : /var/mobile directory. Tap on Mobilesubstrate .deb file that you downloaded, and then tap on “Installer” button to install it.

5) Once done, reboot your device in jailbroken state. Start Cydia, search for Mobile Substrate and you should now have the latest version which supports iOS 4.3.

Even with this updated version of Mobile Substrate which fixes ASLR issues, ultrasn0w unlock wont work. Therefore there is NO unlock for iOS 4.3 yet. If your iPhone relies on a unlock, DO NOT update to stock iOS 4.3.