Greenpois0n (jailbreak)

greenpois0n is a jailbreak utility released for macOS, Windows, and Linux to jailbreak iOS 3.2.2, 4.1, and later, 4.2.1.

RC1 - RC4
Greenpois0n was originally written using two exploits: SHAtter (a bootrom exploit) as well as a userland kernel exploit provided by Comex to make the jailbreak untethered. A release date of 10/10/10 10:10:10 AM (GMT) was announced, as well as the list of supported devices. Due to the nature of SHAtter, only devices using the A4 Processor were supported. geohot later released another jailbreak (limera1n using a different bootrom exploit) on 2010, which led to a delay in greenpois0n's release (to implement geohot's exploit, not SHAtter).

RC5
Posixninja and the rest of Chronic Dev released a Mac-exclusive version of greenpois0n RC5 on 2011, which performs an untethered jailbreak on iOS 4.2.1 for most devices that support it. Instead of using the Packet Filter Kernel Exploit like RC4 and earlier, RC5 made use of the HFS Legacy Volume Name Stack Buffer Overflow. (This exploit wasn't saved for iOS 4.3 because it was already fixed in the betas with an implementation of ASLR.) Bugs were found, and fixed, in subsequent builds. Two days later, on 2011, Chronic Dev released a Windows version as well. A Linux build was never released.

RC6
Support for the Apple TV (2nd generation) was added. This release was for both Windows and Mac, but not Linux.

Controversy
There was much controversy surrounding the sudden release of limera1n and the motives behind it. The main reasons for the limera1n release were: The reason for this is bootrom exploits are not patchable with software updates. It requires new hardware to fix the security hole. Since the limera1n hole was already discovered and patched by Apple, it benefits the community if SHAtter is saved in hopes of using it with new hardware, like the iPhone 4S, iPod touch (5th generation), and the iPad 2. However, Apple, presumably through internal testing, found out about SHAtter and patched it in the A5 chip released with the iPad 2.
 * Use an exploit that Apple already knew about (newer iBoots shows the exploit patched)
 * Supports more iOS devices than SHAtter
 * Save the SHAtter bootrom exploit for future devices

Supported Devices
greenpois0n RC4 and earlier requires the device to be on either iOS 3.2.2 (iPad) or iOS 4.1 (all other devices). Of the devices that support these firmware revisions, the only one not supported is the iPhone 3G.

greenpois0n RC5 requires the device to be on iOS 4.2.1. It is compatible with every device that has 4.2.1, except for the iPhone 3G. It was released earlier than anticipated, because iOS 4.3 unintentionally blocked the HFS Legacy Volume Name Stack Buffer Overflow exploit.

Output
iPhone 4 with greenpois0n output (via iRecovery): Attempting to initialize greenpois0n Initializing commands Searching for cmd_ramdisk Found cmd_ramdisk string at 0x8401c7ac Found cmd_ramdisk reference at 0x84000d64 Found cmd_ramdisk function at 0x84000cd1 Initializing patches Initializing memory Initializing aes Searching for aes_crypto_cmd Found aes_crypto_cmd string at 0x84021a8c Found aes_crypto_cmd reference at 0x84017bb8 Found aes_crypto_cmd fnction at 0x84017b51 Initializing bdev Initializing image Initializing nvram Initializing kernel Greenpois0n initialized