Google patches actively exploited zero-day bug that affects Chrome users

Update your Chrome again as Google patches second zero-day in two weeks

Before you start to Google for election news, we’d like you to check whether your browser is at the latest and safest version. “Again?”, Chrome users may say. Yes, because Google has found another zero-day vulnerability – that means it’s a hole that is actively being exploited right now.

It’s the second zero-day in Google found in the past two weeks. Last week we reported about CVE-2020-15999 and advised to upgrade to at least version 86.0.4240.111. Today it is the turn of CVE-2020-16009 which is patched in Chrome version 86.0.4240.183 and later.

How do I install Chrome patches?

The easiest way to do it is to allow Chrome to update automatically which basically uses the same method as outlined below but does not require your attention. But you can end up lagging behind if you never close the browser or if something goes wrong, such as an extension stopping you from updating the browser. So, it doesn’t hurt to check now and then. And now would be a good time, given the zero-day vulnerability. My preferred method, which also allows me to keep track, is to have Chrome open the page chrome://settings/help which you can also find by clicking Settings > About Chrome.

If there is an update available, Chrome will notify you and start downloading it. Then it will tell you all you have to do to complete the update is Relaunch the browser.

relaunch to update Chrome

What is this Chrome patch for?

Google has not disclosed what the 0-day does or how it is used. This is habitual as they want to give users a chance to update before giving threat-actors the chance to design their own exploits. But researchers came to the conclusion that it must have something to do with the way the Chrome browser handles Javascript by looking at the changelog.

Chrome changelog for cve-2020-16009

After the update, the security hole should be patched and your settings page should say:

Chrome is up to date

If so, you’re good to go for now.

Stay safe, everyone!

ABOUT THE AUTHOR

Pieter Arntz

Malware Intelligence Researcher

Was a Microsoft MVP in consumer security for 12 years running. Can speak four languages. Smells of rich mahogany and leather-bound books.