CVE-2021-29983 Denial of service in Firefox

What is CVE-2021-29983?

CVE-2021-29983 is a medium-severity denial of service vulnerability in Mozilla Firefox, published on 17 Aug 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 could get stuck in fullscreen mode and not exit it even after normal interactions that should cause it to exit. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 91.

Which versions are affected by CVE-2021-29983?

It affects 1 product.

Products include Mozilla Firefox.

How do I fix CVE-2021-29983?

Upgrade to a fixed version.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-29983 being exploited?

There is no known exploitation of CVE-2021-29983 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-9w32-qj8g-f2cw, UBUNTU-CVE-2021-29983.