Zoom issues patch for serious security flaw in its MacOS app

15 Aug 2022

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First revealed by security researcher Patrick Wardle, certain versions of Zoom for MacOS contained a vulnerability that could give hackers root privileges.

Zoom has issued a patch for a serious security flaw in its MacOS app that could allow a hacker to take control of a user’s operating system.

In a security bulletin update on Saturday (13 August), Zoom said version 5.7.3 to version 5.11.3 of its MacOS app contains a vulnerability in the auto-update process that can be exploited by a local low-privileged user to “escalate their privileges to root”.

The flaw was revealed by Mac security researcher Patrick Wardle at Def Con, one of the world’s largest hacking conferences, held in Las Vegas last week.

Zoom released the patch soon after Wardle explained to the conference audience how easy it was to access a user’s system using the vulnerability, gaining access to permissions such as modifying, deleting and adding files on the device. He added further details on Twitter.

“Mahalos to Zoom for the (incredibly) quick fix!” Wardle tweeted yesterday (14 August) after Zoom released the update. “Reversing the patch, we see the Zoom installer now invokes lchown to update the permissions of the update .pkg, thus preventing malicious subversion.”

Wardle is a former US National Security Agency hacker and founder of the Objective-See Foundation, a non-profit that develops open-source MacOS security tools.

In 2017, Wardle claimed to have revealed a password exfiltration vulnerability in MacOS High Sierra, which was being rolled out at the time. He demonstrated that it was possible to steal every password in plain text using an app downloaded from the internet without needing the Mac’s Keychain master login.

Zoom classified the latest vulnerability as ‘high’ in severity and urged users to download the latest version of the app.

“Users can help keep themselves secure by applying current updates or downloading the latest Zoom software with all current security updates from https://zoom.us/download,” the company wrote in its security update.

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Vish Gain is a journalist with Silicon Republic