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CVE-2021-37973

Google Chromium Portals Use-After-Free

9.6 CRITICALActively exploited (CISA KEV)EPSS 11.7%
  1. Published8 Oct 2021
  2. Added to CISA KEV3 Nov 2021
  3. Remediation due17 Nov 2021
Actively exploited (CISA KEV)

Google Chromium Portals contains a use-after-free vulnerability that allows a remote attacker, who has compromised the renderer process, to potentially perform a sandbox escape via a crafted HTML page. This vulnerability affects web browsers that utilize Chromium, including Google Chrome and Microsoft Edge.

Added to KEV: 3 Nov 2021Federal remediation due: 17 Nov 2021

Description

Use after free in Portals in Google Chrome prior to 94.0.4606.61 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionRequired
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Affected products

Google Chrome< 94.0.4606.61
Debian Linux10.0 · 11.0
Fedoraproject Fedora33 · 35

Remediation

Fixed in
Google Chrome≥ 94.0.4606.61
Patch & vendor advisories

References

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Frequently asked

Is CVE-2021-37973 being actively exploited?

Yes. CVE-2021-37973 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 3 Nov 2021.

How severe is CVE-2021-37973?

CVE-2021-37973 has a CVSS 3.1 base score of 9.6, rated critical. EPSS estimates a 11.7% probability of exploitation.

Which products are affected by CVE-2021-37973?

Affected products include Google Chrome, Debian Linux, Fedoraproject Fedora.

How do I fix CVE-2021-37973?

Upgrade affected software to a fixed version, for example Google Chrome 94.0.4606.61 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2021-37973 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, a risk for it never ranks below high, and the update that fixes it moves to the Emergency patch lane. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.