screenshots of PS5 running emulators, by Markus95

Scene dev Markus95 has released some more Emulators for PS4 10.01 and PS5 6.50, running with the yet-unpatched Mast1c0re exploit. This is an update to his emulator packs released a few days ago, and it adds 4 more emulators for a total of 10. He’s also fixed some bugs and added functionality (such as zipped ROM support)

What is the Mast1c0re exploit for PS4/PS5?

Mast1c0re is an unpatched vulnerability on PS4 and PS5, running through their PS2 emulation layer. The vulnerability was disclosed, and described with great detail, by PlayStation hacker CTurt in September last year, and a public reimplementation was released by McCaulay Hudson early 2023.

Some specific PS2 games for PS4/PS5 are vulnerable to buffer overflows, which allows us to run unsigned code on the PS4 and PS5. The currently only known exploitable game through this vulnerability is Okage: Shadow King, a PS2 game available for PS4 and PS5 on Sony’s PSN. By loading specifically crafted save files into this game, it is possible to trigger an exploit chain on PS4/PS5 running the most recent firmwares, to then enable some (limited) homebrew capability.

So far the most “user friendly” use case for this vulnerability has been emulation. Keep in mind that for now, emulators are actually limited to the constraints of the PS2 stack within the PS4 or PS5. In other words, you’re running retro emulators that were originally designed to run on a hacked PS2. With all the limitations this implies.

Download Emulators for the Mast1C0re exploit

Markus95 has released an update to his pack of emulators to run with Mast1c0re (download link below). Again, keep in mind that the environment in which these are running is still glitchy and limited, so bugs may happen.

In this 1.1 release, Markus95 has added support for zipped ROMs, but also the possibility to access the pause/quick menu by pressing the touchpad, which lets you change your emu settings for each core, resolution, framerate, etc…

This pack adds emulators for the following consoles/games:

• Handy (Atari Lynx)
• Atari800 (Atari)
• Mednafen_Wswam (Wonderswam)
• Prboom (Doom + mods)

They join the existing list from last week:

• Picodrive (Genesis/Megadrive)
• SMSPlus (Master System and Game Gear)
• SNES9x2002 (Super Nintendo)
• QuickNES (Nintendo Nes)
• Gambatte (Game Boy and Game Boy Color)
• Race (Neo Geo Pocket and Neo Geo Pocket Color)

The developer has also added a video tutorial (in French, but you can use the auto translate feature on youtube) on how to pack PS2 emulators for the PS4/PS5 Mast1c0re exploit. You can check it here.

Download and install:

• Download the emulator pack “Retroarch PS2 v1.1”  here
  • You will need to get your own ROMs and add them to the iso with a tool such has CDGEN
• To run the exploit on your PS4 or PS5, you will need a legit copy of Okage Shadow King. Basic instructions here.

Can we do more with the Mast1c0re exploit?

Although the emulators released above are specifically designed to run within the PS2 emulation layer of the hack, we already have PS4 native code capabilities with the exploit (yes, on PS5 too, I know, it’s a bit tough to think of all those layers). However PS4 execution is currently running with a ROP chain, and there aren’t any ways currently to run “big” homebrew games from within it. Forget also about more advanced PS4 uses such as GoldHEN or more, as long as this isn’t coupled with a Kernel exploit (which, for now, nobody has announced).

Source: Markus95 on Logic-sunrise