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Google Chrome under attack via zero-day flaw — what to do now

Google Chrome
(Image credit: Big Tuna Online/Shutterstock)

Update your desktop Chrome browser, because doing so patches a zero-day flaw that's being actively exploited in the wild by undisclosed hackers. 

Google's official Chrome blog says only that the vulnerability, given the catalog number CVE-2021-21166, is an "object lifecycle issue in audio" with "high" severity and that Google "is aware of reports" that the flaw is being exploited. 

Google's general policy is to not release too many details about vulnerabilities before patches can be widely deployed. This one is considered a zero-day flaw because it was exploited before Chrome was aware the flaw existed.

To update Chrome on Windows and Mac, you often need to just close and then relaunch the browser. But to be sure, click the Settings icon (it looks like three vertical dots) in the top right of the browser window. 

In the resulting pop-out menu, slide your cursor down to Help, then slide over and click "About Google Chrome" in the fly-out menu that appears.

Chrome will open a new tab notifying you whether your browser build is up to date. If it isn't, Chrome will download the update automatically, then prompt you to relaunch the browser. You want to end up on version 89.0.4389.72.

Linux distributions generally update the Chrome browser through routine updates covering all installed software.

The discovery of this vulnerability is credited to Alison Huffman of the Microsoft browser vulnerability research team. Huffman is credited with finding two other flaws patched in this week's Chrome update, which patches a total of 47 flaws.