CVE-2021-21123 Security feature bypass in Chrome

What is CVE-2021-21123?

CVE-2021-21123 is a medium-severity vulnerability in Google Chrome, published on 9 Feb 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

Insufficient data validation in File System API in Google Chrome prior to 88.0.4324.96 allowed a remote attacker to bypass filesystem restrictions via a crafted HTML page.

Weakness: CWE-20

Which versions are affected by CVE-2021-21123?

It affects 2 products.

Products include Google Chrome, Microsoft Edge Chromium.

How do I fix CVE-2021-21123?

Upgrade to a fixed version.

Is CVE-2021-21123 being exploited?

There is no known exploitation of CVE-2021-21123 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

Other vulnerabilities in Google Chrome

• CVE-2022-4135 Google Chromium GPU Heap Buffer Overflow Exploited Critical 9.6
• CVE-2020-16017 Google Chrome Use-After-Free Exploited Critical 9.6
• CVE-2020-16010 Google Chrome for Android UI Heap Buffer Overflow Exploited Critical 9.6
• CVE-2026-87491 Google Chromium V8 Out of Bounds Write Exploited High 8.8
• CVE-2026-85046 Google Chromium V8 Type Confusion Exploited High 8.8

All Google Chrome vulnerabilities

Sources

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

Also known as DEBIAN-CVE-2021-21123, GHSA-2g4x-fv7q-8jrf, UBUNTU-CVE-2021-21123.