MacRumours said that Apple has begun taking action to address a weakness in its in-app purchase technology, which has enabled customers to download content free-of-charge.

According to the report, developers are now reporting that receipts for content issued by Apple now include a “unique identifier” characteristic. Previously, no link was made between devices and content, meaning a receipt could be “shared” among multiple users.

However, it was noted that currently Apple is using the Unique Device Identifier (UDID) to link users to purchases – a method that Apple has previously told developers not to use. It is not clear if Apple’s current plans are a stop-gap until it introduces another identifying method.

According to The Next Web, UDID is not used in all instances. It appears the difference may be related to whether a developer has already updated an app to comply with the requirement that UDID is not used or not.

Last week, it was reported that a Russian hacker had worked out the way to bypass Apple’s in-app purchase mechanisms, although it was noted that his method required App Store user names and passwords to be transmitted to servers under his control.