This WebKit exploit, which is based upon a JavaScript vulnerability found as part of Project Zero in 2018, works on Firmwares 6.00-6.72 with Fire30 noting that Sony patched it in Firmware 7.00 meaning that the latest firmware isn’t vulnerable to it.
What does a WebKit exploit mean?

While FW 6.20 has had a public WebKit exploit for a while, a public kernel exploit is needed for a full hacking solution

While the release of a WebKit is exploit, it’s important to keep in mind the following:

  • WebKit exploits don’t equate to anything tangible like a full/partial hacking solution to the end-user
    • However, they are useful to developers as entry points in the initial steps of an exploit chain

  • A kernel exploit is required in order to get the things currently available on FW 5.05/7 or lower
  • It’s important to note that FW 6.00-6.20 have had a public WebKit exploit, by SpecterDev, since March and not much came out of that when it comes to end-user functionality

As a result, it’s important to keep in mind that this exploit will not suffice for a full hacking solution but it does give some hope for future PlayStation 4 hacking developments as some interest is still there.

http://wololo.net/2020/01/01/news-fi...r-ps4-fw-6-xx/