CVE-2021-23962 Use after free in Firefox

What is CVE-2021-23962?

CVE-2021-23962 is a high-severity use after free vulnerability in Mozilla Firefox, published on 26 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

Incorrect use of the '<RowCountChanged>' method could have led to a user-after-poison and a potentially exploitable crash. This vulnerability affects Firefox < 85.

Which versions are affected by CVE-2021-23962?

It affects 1 product.

Products include Mozilla Firefox.

How do I fix CVE-2021-23962?

Upgrade to a fixed version.

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-2021-23962 being exploited?

There is no known exploitation of CVE-2021-23962 in the wild and no public exploit code.

Other vulnerabilities in Mozilla Firefox

• CVE-2019-11708 Mozilla Firefox and Thunderbird Sandbox Escape Exploited Critical 10.0
• CVE-2010-3765 Mozilla Multiple Products Remote Code Execution Exploited Critical 9.8
• CVE-2022-26486 Mozilla Firefox Use-After-Free Exploited Critical 9.6
• CVE-2022-26485 Mozilla Firefox Use-After-Free Exploited High 8.8
• CVE-2019-11707 Mozilla Firefox and Thunderbird Type Confusion Exploited High 8.8

All Mozilla Firefox vulnerabilities

Sources

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

Also known as GHSA-cgj5-m6v7-hf6x, UBUNTU-CVE-2021-23962.