Chinese smartphone maker Xiaomi says it has upgraded its operating system to ensure users know when data from users' address books is collected.
The announcement follows a report by a computer security firm saying the Chinese budget smartphone maker was taking personal data without permission.
Xiaomi says it has fixed a loophole in its cloud messaging system that had triggered the unauthorized data transfer and that the operating system upgrade has been rolled out.
Xiaomi Vice President Hugo Barra has apologized for the unauthorized data collection, saying the company only collects phone numbers in users' address books to see if the users are online.