This weekend I searching information about how to jailbreak PS3 12Gb Super Slim with OFW (firmware official) 4.50, this version is published in October-November 2013.
In many forums/blogs/pages people offer .PUP for downgrade PS3 to version 3.55, this version needed to can install CFW (custom firmware), all what I found it's a scam, what offers to you download .PUP for free from page X with putting your phone number and with a small letter at the end of a page they say what you will pay > 30 euros and you will subscribed to X services.
So at the moment the unique solution is flashing with E3 Flasher or with the Cobra ODE.
Here you can see how to install Cobra ODE on PS3 serie 4000 (SuperSlim).
This information published just for education purpose and protect you from scams, if you do jailbreak the author is not responsible for any damages, you do it at your own risk. In many countries jailbreak is illegal.