Skip to content
Fencer Vulns
critical 9.6

CVE-2021-37973 kev in the critical feed json

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 pote…

published 2021-10-08 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-24446

cvss
9.6
version 3.1, CNA
cisa kev
Exploited
added 2021-11-03
epss
11.7%
EPSS 11.7% chance of exploitation in 30 days, percentile 96%
public exploits
0
none known

Summary

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.

Patch / fix

cisa required action Apply updates per vendor instructions.

  • Google Chrome 94.0.4606.61
  • chromium Debian 14, Debian 13, Debian 12 97.0.4692.71-0.1

debian advisories DEBIAN-CVE-2021-37973

  • chromium-browser Ubuntu 18.04 LTS 94.0.4606.71-0ubuntu0.18.04.1

ubuntu advisories UBUNTU-CVE-2021-37973

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • chromium openSUSE Tumbleweed 94.0.4606.71-1.1
  • chromium openSUSE Tumbleweed 113.0.5672.92-1.1
  • chromium openSUSE Leap 15.2 94.0.4606.81-lp152.2.132.1
  • chromium Package Hub 15 SP3, openSUSE Leap 15.3 94.0.4606.71-bp153.2.31.1

opensuse advisories openSUSE-SU-2024:11555-1openSUSE-SU-2024:12948-1openSUSE-SU-2021:1350-1openSUSE-SU-2021:1339-1

  • qt5-qtwebengine Alpine 3.14 5.15.3_git20211006-r1
  • qt5-qtwebengine Alpine 3.23, Alpine 3.22, Alpine 3.21 +6 more 5.15.3_git20211006-r3

alpine advisories ALPINE-CVE-2021-37973

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • chromium Arch Linux 94.0.4606.61-1
  • vivaldi Arch Linux 4.2.2406.52-1

arch linux advisories AVG-2419AVG-2426

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-37973 updated cvss 8.8

chromium-browser: Use after free in Portals

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Timeline

  1. Found exploited as a 0-day (Project Zero)
  2. 0-day patched (Project Zero)
  3. Published
  4. Added to CISA KEV
  5. CISA patch deadline
  6. CISA SSVC: exploitation active

Known exploited

Added
5 y ago
Patch by
2021-11-17 (4 y ago)
Ransomware
Not known
Required action
Apply updates per vendor instructions.
Vendor, product
Google, Chromium Portals
CISA name
Google Chromium Portals Use-After-Free Vulnerability

Zero-day

Detected in real attacks while still unknown to the vendor and the public, per Google Project Zero's 0day In-the-Wild tracker.

Found
2021-09-21
Patched
2021-09-24
Details
project zero tracker

CISA SSVC

Exploitation
Active, exploited in the wild
Automatable
no
Technical impact
total
Assessed
21 mo ago

Exploit prediction

11.73% chance of exploitation in the next 30 days, higher than 96% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
NVD 3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CNA 3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • Google Chrome

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.