Mast1c0re is all the talk of the town now that’s it’s been demonstrated that you can actually do useful stuff with it, on the latest PS4 and PS5 Firmwares. New releases are happening at a rapid pace. In particular McCaulay has published an ELF loader earlier today, possibly more practical for running homebrew than the existing iso loader.

What is Mast1c0re for PS5 and PS4?

Mast1c0re is an unpatched exploit for PS4 and PS5, which leverages a vulnerability in the PS2 emulation layer of Sony’s newer consoles. The vulnerability was disclosed, and described with great detail, by PlayStation hacker CTurt in September last year, but no full “user friendly” implementation was released then.

Back then, CTurt stated Sony had no plan to fix the vulnerability. It has now been fully confirmed that the vulnerability is still here, in the latest PS5 6.50 firmware and in PS4 10.01 as well,  as of February 2023.

Recently released Beta firmwares PS5 7.00 and PS4 10.50 still need to be confirmed, but there’s good reason to believe they are vulnerable as well. People who have been trying the exploit on these firmwares could confirm the exploit is here, but correct offsets matching these firmwares need to be found/implemented for the rest of the exploit chain to work.

Mast1c0re ELF Loader & PS4 10.01 Support

Isos are the typical format for PS2 Discs, but when it comes to running homebrew or other unsigned code, an ELF file is easier to produce and does the job with less intermediate steps. I assume that’s why McCaulay released an ELF loader to go with the Mast1c0re exploit today. He also provided a GUI to run on your computer in order to upload the ELF file to the console running the exploit (and you may use his command line script as well).

In parallel, thanks to help from Echo Stretch and Zecoxao, PS4 10.01 support has been added to the exploit, with matching savedata available on Mccaulay’s github.

A couple of notes:

* It may take a time or two. So don’t worry if the game crashes.
* Remember that you have to send the elf file first, then the .ISO
* Don’t update to 10.01 at this time.

— mbcrump – PlayStation 4/5 Homebrew Tutorials (@crump_youtube) February 21, 2023

Download/Run Mast1c0re ELF Loader

Note: You know the drill by now, this release is compatible up to PS4 10.01 and PS5 6.50 included, possibly higher firmwares as well at the time of writing, although you need to own a legit copy of Game Okage: Shadow King (a PS2 game that you can run on PS4/PS5) as the entry point for the exploit.

• Download the VMC0.card that matches your system here
  • Download the GUI to send elf files there as well
  • And grab also some sample ELF files there while you’re at it
  • Look, you might as well download the whole thing, ok?
• We have a tutorial here on how to create the exploit and run it on your console once you have the VMC0.card file
• Once the exploit is running on your console, you can send the ELF file using the GUI, or with the following command line

  python3 mast1c0re-send-file.py --ip <ip> --file ps-load-game-net-PS4-5-05.elf

   

Note: For those of you who are on lower firmwares (and therefore can’t get access to the Okage game on PSN), the general consensus seems to be that you shouldn’t update your console, until something more substantial is released. Of course, the decision remains yours.

Source: @_McCaulay