CVE-2021-37973 Google Chromium Portals Use-After-Free

What is CVE-2021-37973?

CVE-2021-37973 is a critical use after free vulnerability in Debian Debian Linux, published on 8 Oct 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official 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.

Weakness: CWE-416

Which versions are affected by CVE-2021-37973?

It affects 3 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Google Chrome.

How do I fix CVE-2021-37973?

Upgrade to a fixed version. US federal agencies must fix it by 17 Nov 2021.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2021-37973 being exploited?

Yes. Attackers have exploited CVE-2021-37973 in the wild since at least 3 Nov 2021.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-37973, GHSA-w2c8-qc3j-3xr5, UBUNTU-CVE-2021-37973.