Failure in the popular WhatsApp call app may allow outsiders to access other users’ full call history when moving to new phone numbers. The glitch was first reported by Abby Fuller, an employee of Amazon’s cloud computing division, but was further bolstered by reports later.
The root of the malfunction is that the Watsap app associates the call history (and its server-backed backup) with the user’s personal phone number. When that number is “abandoned” and is no longer in use, the app should automatically delete all call history after 45 days. However, according to Fuller, even though the number had been owned for more than 45 days before installing the app, as soon as it was installed, all the calls made by the previous user holding the same number were restored.
This malfunction will not help an intruder who wants to gain access to a specific user’s call history (not so easy to “snatch” a phone number), but it can cause unpleasantness when switching a phone number between different employees in the same company, or family members. Watsap’s response or Facebook parent’s report to Facebook has not yet been published.