Google · Chromium Portals
CVE-2021-37973
Google Chromium Portals Use-After-Free Vulnerability
What it is
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.
CISA: 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.
What to do
Apply updates per vendor instructions.
Deadline for US federal agencies: November 17, 2021
- Added to the CISA list
- November 3, 2021
- Published
- October 8, 2021
- Severity
- Critical 9.6 CVSS 3.1
- Chance of attacks in the next 30 days (EPSS)
- 12% in the top 4.0% of all known vulnerabilities
- Weakness
- CWE-416
- More details
- NVD · CVE.org · CISA
All references (5)
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4DDW7HAHTS3S…
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PM7MOYYHJSWL…
- https://www.debian.org/security/2022/dsa-5046
- https://crbug.com/1251727
- https://chromereleases.googleblog.com/2021/09/stable-channel-update-for-desktop_24.html
More exploited flaws from Google
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Oct 27, 2026 | Unchecked Return Value | Brotli | Critical 9.2 | 55% |
| Sep 16, 2026 | Improper Authorization | Pixel | High 8.8 | 0.6% |
| Sep 9, 2026 | Out of Bounds Write | Chromium V8 | High 8.8 | 3.5% |
| Sep 4, 2026 | Type Confusion | Chromium V8 | High 8.8 | 1.8% |
| Jun 9, 2026 | Out-of-Bounds Read and Write | Chromium V8 | High 8.8 | 2.4% |
| Apr 1, 2026 | Use-After-Free | Dawn | High 8.8 | 14% |
| Mar 13, 2026 | Out-of-Bounds Write | Skia | High 8.8 | 2.3% |
| Mar 13, 2026 | Improper Restriction of Operations Within the Bounds of a Memory Buffer | Chromium V8 | High 8.8 | 2.7% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.