Earlier this month, the technology firm announced it was temporarily disabling the app until the issue could be resolved.
As part of the latest update to its mobile operating system – iOS 12.4 – which was made available to users on Monday, Apple said a “security fix” had been included for the app and it had been reactivated on Apple Watch devices.
The app allows two users, each with an Apple Watch and who have accepted an invitation to chat from one another, to send audio clips back and forth using a “push to talk” button on the Watch screen – similar to a traditional walkie talkie.
At the time of the bug’s discovery, Apple admitted it could have allowed a person to listen in on someone else’s iPhone without consent, however there had been no evidence of the flaw having been used.
The technology giant apologised to its customers, adding that it takes the “security and privacy of our customers extremely seriously”.
Earlier this year, Apple temporarily disabled its Group FaceTime calling feature after a glitch was discovered which in some cases enabled people to listen in on someone they were calling even before the call was answered.
A fix was issued for the bug shortly after it was discovered.
The iOS 12.4 update also includes a new “iPhone migration” feature which will allow users to “wirelessly transfer data and migrate directly from an old iPhone to a new iPhone during setup”.