Security researchers have discovered a critical vulnerability with WhatsApp that exposes the phone numbers of more than 3 billion users worldwide.
The privacy flaw could be used by cyber criminals to gather profile information and infer the identities of users of the world’s most popular messaging app, which could then be used to carry out highly-targeted attacks.
Uncovered by a team from the University of Vienna and SBA Research, the privacy weakness centres on WhatsApp’s contact discovery mechanism, which asks users’ for permission to match mobile numbers in their address book to the app’s