CVE-2019-9793 Memory corruption in Firefox

What is CVE-2019-9793?

CVE-2019-9793 is a medium-severity memory corruption vulnerability in Mozilla Firefox, published on 26 Apr 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A mechanism was discovered that removes some bounds checking for string, array, or typed array accesses if Spectre mitigations have been disabled. This vulnerability could allow an attacker to create an arbitrary value in compiled JavaScript, for which the range analysis will infer a fully controlled, incorrect range in circumstances where users have explicitly disabled Spectre mitigations. *Note: Spectre mitigations are currently enabled for all users by default settings.*. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

Weakness: CWE-119

Which versions are affected by CVE-2019-9793?

It affects 3 products.

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

How do I fix CVE-2019-9793?

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-2019-9793 being exploited?

There is no known exploitation of CVE-2019-9793 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-2019-9793, GHSA-w86v-mv97-qh72, UBUNTU-CVE-2019-9793.