December 13, 2021 may go down in history as the day the PlayStation 4 finally got blown wide open, as a trio of console hackers just released a new, ready-to-run kernel exploit for the PlayStation 4 and PlayStation 4 Pro that works on firmware version 9.00 and earlier. In other words, running homebrew apps and unauthorized copies of games just became feasible for a very significant chunk of PS4 owners.
The jailbreak, dubbed “pOOBs4,” is credited to PlayStation scene hackers/developers SpecterDev, ChendoChap, and Znullptr, with thanks given to Sleirsgoevy for their webkit browser exploit and (famous PlayStation hacking god) TheFloW for discovering the actual filesystem bug that allows this exploit to work. The jailbreak requires network access and a USB key containing a special file. After it runs, the console is free to receive a payload from a PC, such as the Mira Project custom firmware or the GoldHEN homebrew enabler.
The first inkling something was up came yesterday evening when noted PlayStation scene hacker/developer SpecterDev tweeted a video showing custom firmware running on a version 9.00 firmware PlayStation 4.
Znullptr spoke up a few hours later, tweeting that the exploit was real and what’s more, the kernel exploit the jailbreak utilizes should work on the PS5 as well. However, a PS5 version has not yet been created, in part due to the lead dev not yet having a PS5. Relatable.
pOOBs4 is not the first time hackers have gained the ability to execute arbitrary code on the PlayStation 4, but it’s definitely the most notable because prior exploits required would-be exploiters to keep their systems on older firmware versions that most people had already left behind. As a result, only a small subset of PlayStation 4 consoles was exploitable at any given time, and users couldn’t play newer games that required later firmware versions to run.
In contrast, Sony’s now-exploitable version 9.00 firmware just came out on September 15, and the subsequent (and non-exploitable) version 9.03 on December 1. In effect, all PS4 owners who haven’t updated their consoles for the last two weeks are now able to jailbreak their systems, install custom firmware, and, well, install and run whatever they want afterward. This goose looks cooked. And that’s before considering Znullptr’s note that the kernel exploit potentially applies to PS5 as well. Better stick a pin in that.
No console remains unhackable forever, and PlayStation 4 had a fairly lengthy run. And while it appears that streak may be largely over, today may also mark the beginning of a new era of easy-to-access homebrew development on Sony’s cheap, relatively powerful hardware.