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limera1n
This is geohot's jailbreak utility. It uses an undisclosed bootrom exploit and comex's Packet Filter Kernel Exploit to achieve an untethered jailbreak on newer devices. The following devices are technically supported:
- iPhone 3GS
- iPhone 4
- iPod touch 3G
- iPod touch 4G
- iPad
- AppleTV 2G (creates a bare-bones jailbreak by mounting '/' as read/write in /etc/fstab)
limera1n 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.
Release Date: October 9, 2010
Supported OS's: Mac OS X, Windows
Supported Operations: hacktivation, jailbreaking
Contents
Release text
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
brought to you by geohot
hacktivates
Mac coming in 7 years
donations keep support alive
Credit
- geohot - The program itself, and the bootrom exploit.
- comex - The userland exploit that allows limera1n to run untethered.
Changelog
BETA 1 | 9 Oct 2010 XX:XX GMT | 2f2b09a6ed5c5613d5361d8a9d0696b6 | First release. |
BETA 2 | 10 Oct 2010 XX:XX GMT | a70dccb3dfc0e505687424184dc3d1ce | Fixed kernel patching magic. Rerun BETA2+ over BETA1. |
BETA 3 | 10 Oct 2010 XX:XX GMT | 81730090f7de1576268ee8c2407c3d35 | Fixed an issue with iPhone 3GS (new bootrom) |
BETA 4 | 10 Oct 2010 XX:XX GMT | d901c4b3a544983f095b0d03eb94e4db | Uninstall fixed, respring fixed |
RC1 | 11 Oct 2010 XX:XX GMT | 0622d99ffe4c25f75c720a689853845f | out of beta! afc2, reliability improvements, no reboot for cydia, 2kb smaller |
RC1b | 11 Oct 2010 XX:XX GMT | fc6f7d696a57c3baede49bdff8a7f43f | addresses an install issue, mainly with iPads |
Final | 11 Oct 2010 23:XX GMT | fc6f7d696a57c3baede49bdff8a7f43f | (same as RC1b) |
Technical Information
Basics
- limera1n has nothing to do with SHAtter at all.
- limera1n uses a bootrom exploit to achieve the tethered jailbreak and unsigned code execution.
- limera1n uses a userland exploit to make it untethered, which was developed by comex.
- limera1n uses a hacktivation dylib to perform hacktivation.
Exploits
limera1n reuses the usb_control_msg(0x21,2) but exploits a different vulnerability.
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"
"setenv auto-boot true reset geohot done"
Interesting Messages
"geohot black is the new purple"
"blackra1n start: %d current IRQ mask is %8.8X usb irq disabled...shhh fxns found @ %8.8X %8.8X found iBoot @ %8.8X i'm back from IRQland... 3g detected, kicking nor nor kicked memcpy done iBoot restored!!! found command table @ %8.8X cmd_geohot added time to pray...%8.8X"
"2.2X send command(%d): %s send exploit!!! sent data to copy: %X sent shellcode: %X has real length %X never freed: %X sent fake data to timeout: %X sent exploit to heap overflow: %X sending file with length: 0x%X Mingw runtime failure: VirtualQuery failed for %d bytes at address %p Unknown pseudo relocation protocol version %d. Unknown pseudo relocation bit size %d."
Controversy
The release of this jailbreak was specifically designed to pressure Chronic Dev (team) into not releasing SHAtter, but to instead implement the limera1n exploit into greenpois0n; after releasing limera1n, releasing SHAtter would uselessly disclose another bootrom exploit to Apple.
Geohot's rationale is that Apple already discovered, through internal testing, the limera1n exploit, making it very likely that it will be fixed in the next bootrom revision. 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 for an indefinite amount of time.
Limera1n's untethered userland exploit for iOS 4.0 and 4.1 was obtained by geohot under questionable circumstances from comex. Comex did end up fixing the kernel patching code by beta2, so as to not break users' devices.
Hacktivation
Limera1n will copy hacktivation.dylib to /usr/lib and change entries to com.apple.mobile.lockdown.plist, whether it has been activated using iTunes or not. This, while helpful to many, can also be harmful to legitimate activators. For a guide on how to remove this hacktivation on iTunes activated devices, see the link below.