Apple Updates Boot ROM in new iPhone 3GS Models to Prevent Jailbreaking

BY Jason

Published 14 Oct 2009

iPhone 3G S performance comparison

The iPhone hacking community has recently managed to stay ahead of the cat and mouse game of jailbreaking the iPhone, thanks to blackra1n, Geohot’s amazingly easy jailbreaking tool and iPhone Dev Team’s PwnageTool.

But looks like Apple has just upped the ante. iClarified is reporting that Apple has started shipping new iPhone 3GS models with updated boot ROM that is not vulnerable to the 24kpwn exploit that has been used to jailbreak iPhone 3GS.

iClarified reports:

Apple is now shipping the iPhone 3GS with a new Bootrom that is not vulnerable to the 24kpwn exploit.

The iBoot-359.3.2 started to ship last week. A screenshot posted by Mathieulh shows the new version number.

MuscleNerd from the iPhone Dev Team confirmed that if the updated boot ROM is no longer vulnerable to the 24kpwn exploit then it might not be able jailbreak these new iPhone 3GS models currently. He tweeted:

“oh oh, from what @cpich3g + @Mathieulh have found so far, a normal untethered JB may be in jeopardy in brand new 3GS units”

It’s the first time Apple seems to have updated the boot ROM on an existing iPhone model as they have typically done this when they release new iPhone models (once a year).

As ModMyI explains:

The bootrom is a snippet of code that runs at startup time, and checks on the status of the boot image. It's generally used to verify that the image has not been corrupted, but can also be used to check for unauthorized firmware. The 24kpwn exploit – otherwise known as 0x24000 Segment Overflow – bypassed the signature checks on iBoot and allowed unsigned firmware to be loaded.

If you want to find out the version of the boot ROM running on your iPhone 3GS then the only way to achieve this is to check the System Profiler while the phone is in DFU mode.

As always, let us know your thoughts about Apple’s latest attempt to prevent jailbreaking in the comments.

[via iClarified, ModMyI]

Follow us on Twitter