WhatsApp fixes dangerous flaw in Web app

Malware could be delivered by changing a vCard's file extension

WhatsApp, the widely used messaging program, has fixed a dangerous flaw in its Web app that could be used to trick people into installing malware, according to Check Point.

The flaw could affect as many as 200 million people who use WhatsApp's web interface, wrote Oded Vanunu, Check Point's group manager for security research and penetration.

"All an attacker needed to do to exploit the vulnerability was to send a user a seemingly innocent vCard containing malicious code," he wrote.

The flaw was found by a Check Point researcher, Kasif Dekel. He found that the Web version of WhatsApp failed to properly filter electronic business cards in the vCard format.

Dekel found it was possible to change the file extension for a vCard to .bat, or a batch executable script. WhatsApp thinks a user is just receiving a vCard, but it's actually executable code.

"This means once the victim clicks the downloaded file (which he assumes is a contact card), the code inside the batch file runs on his computer," Dekel wrote.

An attacker just needs the victim's phone number to send the malicious code and for the recipient to accept it.

Check Point disclosed the flaw to WhatsApp on Aug. 21, and WhatApp released an update for Web clients on Aug. 27. The up-to-date version is v0.1.4481.

Check Point waited until Tuesday to publicly disclose the vulnerability.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Jeremy Kirk

IDG News Service
Show Comments

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?