Apparently, the phone numbers of more than 500 million Facebook users have been accessible - and for sale - on the Internet. A developer has created a Telegram bot that provides the phone numbers of users of the social network from more than fifteen countries, including the United States, Australia, the United Kingdom and Canada.
All you have to do is enter the user's Facebook ID (which can be obtained from the URL of their profile) for the bot to indicate their phone number. The bot also works in reverse: if you enter a phone number, it will tell you what the user's Facebook ID is and you will be able to know what their profile is.
Of course, the bot provides access only to the first digits of the phone number you are looking for. If you want to have all the complete information, you will have to buy a series of credits. Each credit is worth $ 20, and up to 10,000 can be purchased if desired.
The information is not completely up-to-date, as it contains records for years, but Facebook has confirmed to Motherboard that the vulnerability existed, although it was fixed in August 2019. That is, the developer of the Telegram bot could have access to those records thanks to a vulnerability that allowed for mass scrapping on Facebook and obtaining users' phone numbers.
Facebook users often provide their phone to the social network for various reasons, such as recovering their password or, until 2019, to be able to receive contact suggestions .
But in addition, the phone number is also requested to be able to access double authentication , which, in theory, would provide them with more security on the social network. Facebook would send an SMS to their phone number if there is an unacknowledged access attempt to their account, so that they can certify that they are perhaps themselves, trying to enter from another location.