Absinthe

From The iPhone Wiki
Revision as of 15:03, 21 January 2012 by Http (talk | contribs) (Installation: removed wrong info)
Jump to: navigation, search

Absinthe is the S5L8940 userland jailbreak tool for iPhone 4S and iPad 2 on iOS 5.0 (iPhone 4S only), 5.0.1 (9A405) and iOS 5.0.1 build 9A406 on iPhone 4S. This tool was released on January 20, 2012, and is available in three incarnations:

Installation

The jailbreak packs Corona for the S5L8940 and the rest of the firmware patches in a regular iTunes backup and then restores this backup on to the device, which injects the required files. It is then completed by opening a web clip added to the home screen by Absinthe. If this doesn't work, for example, because the greenpois0n website is down due to the number of people attempting to jailbreak, an alternative is to enable a specially crafted VPN connection in the Settings app.

Exploit

Main article: Corona


This jailbreak uses the Racoon String Format Overflow Exploit and HFS Heap Overflow from Corona for untether. The exact exploit to jailbreak the two devices is not known yet, but it is assumed that the web clip loads a page that requires an IPsec VPN connection, which causes the racoon daemon to start and run the jailbreak payload.

However, some poking reveals some unique means of injection. At some point in the jailbreak process, BackupAgent is intentionally crashed to produce a crash log. The jailbreak payload reads this crash log in order to obtain the memory address of libcopyfile.dylib to continue with the exploit.