Zoom Mac app flaw sparks serious security concerns—and it's up to you to fix it Credit: ZoomSupplied Art
Security

Zoom Mac app flaw sparks serious security concerns—and it's up to you to fix it

If you’ve ever downloaded the Zoom app to participate in a video conference, your Mac may be at risk—even if you’ve already deleted it. In a Medium post, security researcher Jonathan Leitschuh discovered a serious flaw that could allow a website to access your Mac’s camera without your knowledge or permission.

As Leitschuh explains, the vulnerability stems from Zoom’s quest for simplicity. As the service works, you can just send anyone a Zoom meeting link which will in turn automatically open the Zoom client installed on their machine. In case you’ve deleted the app, Zoom keeps a localhost web server running silently on your Mac, Leitschuh said, so the Zoom client will reinstall when a link is clicked without requiring any user interaction on your behalf besides visiting a webpage.

That raises a whole lot of red flags. But even beyond the practice of surreptitiously running a localhost web server on hundreds of thousands of Macs around the world, Leitschuh unearthed a vulnerability that “allows any website to forcibly join a user to a Zoom call, with their video camera activated, without the user's permission … and would have allowed any webpage to DOS (Denial of Service) a Mac by repeatedly joining a user to an invalid call.”

Leitschuh says Zoom dragged its feet on disclosing the vulnerability after being contacted in March, having only implemented a “quick fix” in late June. However, after he published the Medium post Monday, the company responded with a workaround rather than a true fix: “In light of this concern, we decided to give our users even more control of their video settings. As part of our upcoming July 2019 release, Zoom will apply and save the user’s video preference from their first Zoom meeting to all future Zoom meetings. Users and system administrators can still configure their client video settings to turn OFF video when joining a meeting. This change will apply to all client platforms.”

zoom flaw IDG

You'll need to check this box to shut down the ability for websites to access your camera.

Zoom explains that changes implemented by Apple in Safari 12 that “requires a user to confirm that they want to start the Zoom client prior to joining every meeting.” In order to save users an extra click, Zoom installed the localhost web server as “a legitimate solution to a poor user experience problem.”

Zoom also claims that it has no evidence of a Mac being subjected to a DOS attack, which it describes as a “empirically a low risk vulnerability.” It also announced it will be implementing a public vulnerability disclosure program within the next several weeks.

However, Zoom is putting the onus on users to protect their Mac’s camera against hijacking. The latest update to the app doesn’t fix the flaw or remove the localhost server, but it does save the user’s desired camera settings. So to remove the risk of a website accessing your camera, you need to go into the Zoom app settings and select the "Turn off my video when joining a meeting" option. That’s hardly reassuring, and Zoom hasn’t given any indication that it will be properly fixing the problem in a future update or even keeping the camera off by default.

Disable the Zoom localhost web server

If you want to permanently disable the localhost web server from running on your Mac, you'll need to take a visit to the Terminal and type the following: 

pkill ZoomOpener;rm -rf ~/.zoomus;touch ~/.zoomus &&chmod 000 ~/.zoomus;

Then type:

pkill "RingCentralOpener";rm -rf ~/.ringcentralopener;touch ~/.ringcentralopener &&chmod 000 ~/.ringcentralopener;#

PREVIOUS ARTICLE

« Nvidia's leveled-up GeForce RTX 2060 Super and RTX 2070 Super hit the streets today

NEXT ARTICLE

People actually lined up to buy AMD's new Ryzen 3000 desktop CPUs »
author_image
IDG News Service

The IDG News Service is the world's leading daily source of global IT news, commentary and editorial resources. The News Service distributes content to IDG's more than 300 IT publications in more than 60 countries.

  • Mail

Recommended for You

Trump hits partial pause on Huawei ban, but 5G concerns persist

Phil Muncaster reports on China and beyond

FinancialForce profits from PSA investment

Martin Veitch's inside track on today’s tech trends

Future-proofing the Middle East

Keri Allan looks at the latest trends and technologies

Poll

Do you think your smartphone is making you a workaholic?