The following was taken from a series of unpublished posts I wrote back in September 2012 (almost three years ago). The posts not only detail the exploit I found but also the thought process that led me to it. I intended to publish it as soon as the exploit was patched by Sony or after someone found another exploit on the system by examining the memory dumps. However, as of today, the PSM privilege escalation is still the only known way to execute native ARM code on the PS Vita. Apologizes for the outdated references.
To start, lets brainstorm the different ways we can attack this black box of a device. Typically, a new device is unlocked in a process that usually involves: 1) dumping the device’s RAM/ROM/NAND, 2) analyzing the dumps for information and vulnerabilities, 3) using the vulnerability to create a tool that allows others to easily gain root access.
Last time, I analyzed now update checks worked on the 3DS. That was a straightforward process. CARDBOARD (known colloquially as “System Transfer”) is a bundle of complexity with no less than three separate servers communicating with each other as well as the device. A custom proprietary protocol is used for 3DS to 3DS communication. Finally, we have multiple unique identifiers the console uses to identify itself with Nintendo (serial, certificates, console id, account id, etc). I can’t imagine this will be comprehensive, but I hope that whoever is reading can gain new insight on the complexity of the 3DS ecosystem. Continue reading
Since there isn’t much public documentation on how 3DS updater and the NIM module works, I thought I should write something up. Continue reading
First, some background: the 3DS has two main processors. Last time, I went over how Gateway Ultra exploited the ARM11 processor. However, most of the interesting (from a security perspective) functionalities are handled by a separate ARM946 processor. The ARM9 processor is in charge of the initial system bootup, some system services, and most importantly all the cryptographic functions such as encryption/decryption and signature/verification. In this post, we will look at how to run (privileged) code on the ARM9 processor with privileged access to the ARM11 processor. Please note that this writeup is a work in progress as I have not completely figured out how the exploit works (only the main parts of it). Specifically there are a couple of things that I do not know if it is done for the sake of the exploit or if it is done purely for stability or obfuscation. From a developer’s perspective, it doesn’t matter because as long as you perform all the steps, you will achieve code execution. But from a hacker’s perspective, the information is not complete unless all aspects are known and understood. I am posting this now as-is because I do not know when I’ll have time to work on the 3DS again. However, when I do, I will update the post and hopefully clear up all confusion. Continue reading
It’s been a couple of days since my initial analysis of Gateway Ultra, released last week to enable piracy on 3DS. I spent most of this time catching up on the internals of the 3DS. I can’t thank the maintainers of 3dbrew enough (especially yellows8, the master of 3DS reversing) for the amount of detailed and technical knowledge found on the wiki. The first stage was a warmup and did not require any specific 3DS knowledge to reverse. The problem with the second stage is that while it is easy to see the exploit triggered and code to run, the actual exploit itself was not as clear. I looked at all the function calls made and made a couple of hypothesis of where the vulnerability resided, and reversed each function to the end to test my hypothesis. Although there was many dead ends and false leads, the process of reversing all these functions solidified my understanding of the system. Continue reading
When we last left off, we looked at the ROP code that loaded a larger second-part of the payload. Now we will walk through what was loaded and how userland native code execution was achieved. I am still an amateur at 3DS hacking so I am sure to get some things wrong, so please post any corrections you have in the comments and I will update the post as needed. Continue reading
When we last left off, I had spent an excess of 100 hours (I’m not exaggerating since that entire time I was working, I listened to This American Life and went through over a hundred one-hour episodes) soldering and tinkering with the Vita logic board to try to dump the eMMC. I said I was going to buy a eMMC socket from taobao (the socket would have let me clamp a eMMC chip down while pins stick out, allowing the pressure to create a connection) however, I found out that all the sellers of the eMMC socket from taobao don’t ship to the USA and American retailers sell the sockets for $300 (cheapest I could find). So I took another approach. Continue reading