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WhatsApp fixes a flaw that made phone numbers of users public

By Anam Hamid

Published: Jun 11, 2020, 11:42 AM

WhatsApp fixes a flaw that made phone numbers of users public

A WhatsApp vulnerability that allegedly left the phone numbers of around 300,000 people exposed has now been fixed.

The loophole was within the Click to Chat feature which streamlines conversations. It was first revealed by the WhatsApp-focused website WaBetaInfo and later reported by security researcher Athul Jayaram.

The feature lets users create a wa.me/ URL that can be shared with friends and prospective customers to initiate a chat or join a group, without requiring them to save a phone number first.

WhatsApp should have asked Google and other search engines to not index these links. Except that it didn't and that's why all it took was a “site:wa.me” search for phone numbers of some WhatsApp users to show up in search results. Some searches even turned up messages and images.

WhatsApp has now de-index the associated webpages. Phone numbers still remain a part of the short URL, but they will not be indexed by crawlers.

Facebook says it was aware of the issue already

This was no minor flaw and goes as far back as February. Facebook claims it was already working on it when Jayaram escalated it and that the phone numbers he stumbled upon were probably old results cached by Google.

Here is what a WhatsApp spokesperson said on the matter:

While we appreciate this researcher’s report and value the time that he took to share it with us, it did not qualify for a bounty since it merely contained a search engine index of URLs that WhatsApp users chose to make public. All WhatsApp users, including businesses, can block unwanted messages with the tap of a button.

Regardless of what Facebook says, the nowp-fixed flaw is not a good look for a company whose CEO was summoned to Congress over privacy lapses.

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Anam Hamid is a computer scientist turned tech journalist who has a keen interest in the tech world, with a particular focus on smartphones and tablets. She has previously written for Android Headlines and has also been a ghostwriter for several tech and car publications. Anam is not a tech hoarder and believes in using her gadgets for as long as possible. She is concerned about smartphone addiction and its impact on future generations, but she also appreciates the convenience that phones have brought into our lives. Anam is excited about technological advancements like folding screens and under-display sensors, and she often wonders about the future of technology. She values the overall experience of a device more than its individual specs and admires companies that deliver durable, high-quality products. In her free time, Anam enjoys reading, scrolling through Reddit and Instagram, and occasionally refreshing her programming skills through tutorials.

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