A Russian developer has figured out a way to side-step Apple's in-app purchasing service.

The hack, by developer ZonD80, lets users upgrade to full versions of games, download digital items and purchase other content for free, ZDNet reported.

Furthermore, the hack does not require a jailbroken device, working on versions 3 to 6 of Apple's iOS platform.

To take advantage of the exploit (not recommended), users need to install two certificates, change their DNS settings and then enter their Apple ID.

ZDnet also suggested that the developer could simply be gathering Apple credentials in a cyber attack.

Apple has responded to the incident, saying they are investigating the claims.