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Ex-NSA hacker drops new zero-day doom for Zoom

Zack Whittaker

Zoom's troubled year just got worse.

Now that a large portion of the world is working from home to ride out the coronavirus pandemic, Zoom's popularity has rocketed, but also has led to an increased focus on the company's security practices and privacy promises. Hot on the heels of two security researchers finding a Zoom bug that can be abused to steal Windows passwords, another security researcher found two new bugs that can be used to take over a Zoom user's Mac, including tapping into the webcam and microphone.

Patrick Wardle, a former NSA hacker and now principal security researcher at Jamf, dropped the two previously undisclosed flaws on his blog Wednesday, which he shared with TechCrunch.

The two bugs, Wardle said, can be launched by a local attacker — that's where someone has physical control of a vulnerable computer. Once exploited, the attacker can gain and maintain persistent access to the innards of a victim's computer, allowing them to install malware or spyware.

Wardle's first bug piggybacks off a previous finding. Zoom uses a "shady" technique — one that's also used by Mac malware — to install the Mac app without user interaction. Wardle found that a local attacker with low-level user privileges can inject the Zoom installer with malicious code to obtain the highest level of user privileges, known as "root."

Those root-level user privileges mean the attacker can access the underlying macOS operating system, which are typically off-limits to most users, making it easier to run malware or spyware without the user noticing.

The second bug exploits a flaw in how Zoom handles the webcam and microphone on Macs. Zoom, like any app that needs the webcam and microphone, first requires consent from the user. But Wardle said an attacker can inject malicious code into Zoom to trick it into giving the attacker the same access to the webcam and microphone that Zoom already has. Once Wardle tricked Zoom into loading his malicious code, the code will "automatically inherit" any or all of Zoom's access rights, he said — and that includes Zoom's access to the webcam and microphone.

"No additional prompts will be displayed, and the injected code was able to arbitrarily record audio and video," wrote Wardle.

Because Wardle dropped detail of the vulnerabilities on his blog, Zoom has not yet provided a fix. Zoom also did not respond to TechCrunch's request for comment.

In the meanwhile, Wardle said, "if you care about your security and privacy, perhaps stop using Zoom."

Maybe we shouldn’t use Zoom after all