From cybersecuritynews.com
A critical security flaw in WhatsApp has allowed researchers to expose the phone numbers of 3.5 billion users, marking one of the most significant data leaks ever documented.
This vulnerability, rooted in the app’s contact discovery feature, persisted despite warnings to Meta dating back to 2017, raising serious concerns about user privacy on the world’s most popular messaging platform.
The exploit relies on WhatsApp’s built-in mechanism for finding contacts, which reveals whether a user is on the service and public details like profile pictures and status texts when a phone number is entered.
Security researchers from the University of Vienna demonstrated the flaw by systematically querying billions of potential numbers, confirming active accounts at a rate of over 100 million per hour without any restrictions from WhatsApp.
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