CVE-2021-23977 Race condition in Firefox

What is CVE-2021-23977?

CVE-2021-23977 is a medium-severity 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

Firefox for Android suffered from a time-of-check-time-of-use vulnerability that allowed a malicious application to read sensitive data from application directories. Note: This issue is only affected Firefox for Android. Other operating systems are unaffected. This vulnerability affects Firefox < 86.

Weakness: CWE-367

Which versions are affected by CVE-2021-23977?

It affects 1 product.

Products include Mozilla Firefox.

How do I fix CVE-2021-23977?

Upgrade to a fixed version.

Is CVE-2021-23977 being exploited?

There is no known exploitation of CVE-2021-23977 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-cc5x-973x-6p4m, UBUNTU-CVE-2021-23977.