CVE-2021-29988 Memory corruption in Firefox

What is CVE-2021-29988?

CVE-2021-29988 is a high-severity memory corruption 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 incorrectly treated an inline list-item element as a block element, resulting in an out of bounds read or memory corruption, and a potentially exploitable crash. This vulnerability affects Thunderbird < 78.13, Thunderbird < 91, Firefox ESR < 78.13, and Firefox < 91.

Weakness: CWE-787, CWE-125

Which versions are affected by CVE-2021-29988?

It affects 3 products.

Products include Mozilla Firefox, Mozilla Firefox Esr, Mozilla Thunderbird.

How do I fix CVE-2021-29988?

Upgrade to a fixed version.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-29988 being exploited?

There is no known exploitation of CVE-2021-29988 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 DEBIAN-CVE-2021-29988, GHSA-rqrh-6wcg-wqw7, UBUNTU-CVE-2021-29988.