Sony's latest firmware upgrade for the Playstation 3 game machine is closes a loophole that allowed users to run software that enables pirated games to be played on the PS3 console.

Sony officially describes the v3.42 software release as a "minor update" that includes additional security features. However, the update blocks the PSJailbreak and PSGroove applications.

Sony won a court order in early September banning the distribution of the PSJailbreak dongle. The commercial dongle - PS Jailbreak - that allows users to play pirated software. It also targets open source code, known as PSGroove, which allows homemade games to be played on the console.

While the PSGroove software was not originally intended to allow the playing of pirated games, as PSJailbreak does, it has already been modified by other hackers to permit the practice.

Sony has already obtained a court injunction preventing the distribution of the PSJailbreak dongle in Australia.

Sony has not provided specific information what the new firmware actually does.