WhatsApp bug let hackers access computers with only a text message

The past few months have not been good to WhatsApp users. Unfortunately, that doesn't look like it's about to change any time soon.

The Facebook-owned messaging app acknowledged and patched a major vulnerability that gave hackers the ability to access files on a victim's computer. All you had to do to fall prey to this attack was click a disguised link preview sent via the messaging app. In other words, it would have been an easy mistake for users to make.

Importantly, this did not affect every single WhatsApp user. Rather, a WhatsApp user had to have the iOS version of the messaging app paired to either a PC or MacOS WhatsApp desktop app.

"A vulnerability in WhatsApp Desktop when paired with WhatsApp for iPhone allows cross-site scripting and local file reading," reads the Facebook bug report. "Exploiting the vulnerability requires the victim to click a link preview from a specially crafted text message."

In a Feb. 4 blog post, the security researcher who discovered and disclosed the vulnerability detailed his process and noted that WhatsApp should really get its shit together.

"It is 2020," wrote Gal Weizman, "no product should be allowing a full read from the file system and potentially a [remote code execution] from a single message."

Patrick Wardle, a security researcher at Jamf and founder of Objective-See, told Mashable over Twitter direct message that "often desktop versions of apps aren't as well audited or well written ...and thus often open to attacks."

He added that this specific specific bug "was likely rather trivial to exploit," but cautioned against people freaking out.

"[Still]," wrote Wardle, "a super neat bug, and had the potential to impact lots of users (I use WhatsApp desktop), so definitely happy a security researcher uncovered it and that FB patched it quickly."

We reached out to Facebook in an effort to determine how many people were vulnerable to this exploit and how many, if any, were actually affected by it. We've received no response as of press time.

Notably, WhatsApp vulnerabilities can have serious consequences. Just this past month, a security firm hired by Amazon CEO Jeff Bezos claimed in a report that the CEO's phone may have been hacked following the receipt of a malicious WhatsApp message. And while Bezos will be fine, people with less power and resources who fall victim to similar attacks may not fare as well.

Facebook is aware of this, but suggests at least some of the blame should lie elsewhere. Following the news of Bezos' hacked phone, the company's vice president of Europe, the Middle East and Africa, Nicola Mendelsohn, suggested to Bloomberg that Apple is the real problem here.

"One of the things that it highlights is actually some of the potential underlying vulnerabilities that exist on the actual operating systems on phones," Mendelsohn told the publication. "From a WhatsApp perspective, from a Facebook perspective, the thing that we care about the most, the thing that we invest in is making sure that the information that people have with us is safe and secure."

SEE ALSO: Mic on Bezos' hacked phone possibly compromised for months

Which, yeah, great. Making sure WhatsApp information is "safe and secure" sounds great, but perhaps that should include not allowing malicious texts that let hackers access victims' computers? Sounds like a good place to start.

Or, if that's too much, maybe Facebook should start recommending Signal.

UPDATE: Feb. 5, 2020, 2:02 p.m. PST: This story has been updated with comment from Patrick Wardle.