Limera1n

This is geohot's jailbreak utility. It uses his undisclosed exploit, along with comex's userland exploit, to achieve an untethered jailbreak on newer devices.

• iPhone 3GS
• iPhone 4
• iPod touch 2G (support announced, not released)
• iPod touch 3G
• iPod touch 4G
• iPad

It has been demonstrated multiple times by geohot, using blog posts on his now private blog. Geohot showed off a high-res picture of Cydia on an iPhone 4. He displayed an iPod touch 3G with an untethered jailbreak that met MuscleNerd's requirements for a good video. In addition, he took a picture of Cydia and blackra1n icons on his iPad's SpringBoard.

limera1n beta 1 was released on October 9, 2010, delaying the release of greenpois0n, because greenpois0n has to be rewritten to use the limera1n exploit instead of SHAtter. It only supports Windows at the moment and some devices have issues.

Release text

limera1n, 6 months in the making

iPhone 3GS, iPod Touch 3G, iPad, iPhone 4, iPod Touch 4G
4.0-4.1 and beyond+++
limera1n is unpatchable
untethered thanks to jailbreakme star comex
released today to get chronicdev to do the right thing
brought to you by geohot
hacktivates
Mac coming soon
follow the instructions in the box, sadly limera1n isn't one click
that's the price of unpatchability
as usual, donations appreciated but not required
still in beta, pardon my ragged edges
AppleTV is technically supported, but theres no apps yet

zero pictures of my face

Credit

• geohot - the program itself, and bootrom exploit.
• comex - userland exploit that allows limera1n to run untethered.

Changelog

Version	Release time	MD5 Hash	Change comment
RC1 beta 1	9 Oct 2010 XX:XX GMT	2f2b09a6ed5c5613d5361d8a9d0696b6	First release.
RC1 beta 2	9 Oct 2010 XX:XX GMT	a70dccb3dfc0e505687424184dc3d1ce	Fixed kernel patching magic. Rerun BETA2+ over BETA1.
RC1 beta 3	9 Oct 2010 XX:XX GMT	81730090f7de1576268ee8c2407c3d35	Fixed an issue with iPhone 3GS (new bootrom)
RC1 beta 4	9 Oct 2010 XX:XX GMT	d901c4b3a544983f095b0d03eb94e4db	Uninstall fixed, respring fixed

Technical Information

Basics

• limera1n does not use SHAtter.
• limera1n uses a bootrom exploit to achieve the tethered jailbreak and unsigned code execution.
• limera1n uses a userland exploit to make the jailbreak untethered, which was developed by comex.

Exploits

Details of the bootrom exploit to follow.

Process

The jailbreak appears to execute something like the following (in no particular order):

• In recovery1,

"setenv debug-uarts 1
setenv auto-boot false
saveenv"

• In DFU, it uploads a payload.
• In recovery2, it uploads another payload and its ramdisk.

Controversy

The release of this jailbreak is specifically designed to pressure Chronic Dev into not releasing the SHAtter exploit, instead implementing the limera1n exploit into greenpois0n. Now that geohot has released limera1n, releasing SHAtter would uselessly disclose another bootrom exploit to Apple.

geohot's rationale is that Apple has already discovered, through internal testing, the limera1n exploit, making it very likely that it will be fixed in the next bootrom. Because iBoot code is present both in the bootrom and firmware, and because firmware is refreshed much more often that bootrom code, any fix in this code branch would appear first in firmware. geohot observed his limera1n exploit was closed in firmware and concluded that it would almost certainly be fixed in the next bootrom revision, whereas SHAtter still has a chance of remaining useful in the 5th generation iPhone should it not be disclosed at this time.

limera1n's untethered userland exploit was obtained by geohot under questionable circumstances from comex. comex did in fact end up giving his approval for the exploit to be included in limera1n.

External Links

• Picture of limera1n in action
• limera1n.com Official limera1n site
• Mirror Site http://theiphonewiki.com/limera1n
• Limera1n RC Beta2 Dump on Mediafire
• Veence's explanation for release