December 26, 2024

Hackers Begin to Detail the SHAtter Exploit

Posted September 29, 2010 at 3:30pm by iClarified · 14285 views
Hackers have begun to tell the story of the SHAtter exploit, how it was discovered, and how it is being used to bring the next iPhone jailbreak.

SHAtter is an unsigned code execution vulnerability that resides in DFU mode of the S5L8930 bootrom. Uses of this exploit have already involved uploading a pwned iBSS/iBEC to provide access to the AES engine and to run custom ramdisks.

In April 2010 pod2g wrote a USB fuzzer and tested every single USB control message possible on his iPod2,1. The fuzzer found 2 vulnerabilities: - a heap overflow caused by the A1,1 control message - a way to dump the bootrom using USB descriptors request

The team tested both PoC on new generation devices (iPhone2,1, iPod3,1, iPad) and both were already fixed by Apple.

posixninja continued the fuzzing on new gens and found that with a particular sequence of USB messages it was possible to dump the BSS+Heap+Stack (on new gens only). Having a memory dump is really helpful to make exploits and it was also the first time we had this kind of dump, previous bootrom exploits (ex: 24kpwn) were done blind!

Also, his first attempts to dump the memory resulted in rebooting the device. Interesting! We'll see after that this reboot is the base of the SHAtter exploit.


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