A hot potato: With over 2 billion monthly active users globally, WhatsApp is the world's most popular mobile messaging app. But the founder of rival service Telegram thinks people should stay away from Meta's product, which he calls a surveillance tool constantly plagued with security issues.

On Thursday, Pavel Durov wrote in his Telegram channel that people should use any messaging app they like, "but do stay away from WhatsApp - it has now been a surveillance tool for 13 years."

Durov was referencing two security issues discovered in WhatsApp last week that could allow remote code execution on specific devices. Hackers just needed to establish a video call with a victim or send them a specially crafted video file. WhatsApp has since released security updates to address the vulnerabilities.

The Russian national, who now lives in self-imposed exile, noted that even upgrading WhatsApp to the latest version doesn't guarantee you'll be secure. He pointed out that security issues identical to those recently patched were discovered in 2017, 2018, 2019, and 2020. He also notes that WhatsApp didn't have end-to-end encryption before 2016.

"Hackers could have full access (!) to everything on the phones of WhatsApp users," Durov wrote. "Every year we learn about some issue in WhatsApp that puts everything on their users' devices at risk."

Durov says these security issues aren't incidental but "planted backdoors," with a new backdoor added every time a previous one is discovered and removed. "It doesn't matter if you are the richest person on Earth - if you have WhatsApp installed on your phone, all your data from every app on your device is accessible."

That "richest person on Earth" line references the former world's wealthiest person, Jeff Bezos. The Amazon founder's phone was hacked in 2018 via a WhatsApp video message allegedly sent from the account of Saudi crown prince Mohammed bin Salman.

It's easy to imagine Durov disparaging WhatsApp to attract more users to his platform. But the CEO notes that Telegram's 700 million active users and 2 million daily signups mean the privacy-focused service doesn't need any additional promotional.

When asked about Durov's claims, a Meta spokesperson told The Independent, "This is complete rubbish."

Meta isn't the first tech giant to face criticism from Durov. He went after Apple in 2021 for selling "overpriced, obsolete hardware" from the "Middle Ages." More recently, he said Cupertino "intentionally cripples" web apps by not updating WebKit.

In addition to the security vulnerabilities, WhatsApp has faced plenty of claims that it violates users' privacy, including the controversial Facebook data-sharing policy. It was also hit with a record $267 million fine last year for GDPR violations.