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Vulnerability · Published Dec 22, 2022 · Assigned by mozilla

CVE-2021-4129

Critical 9.8

In plain English

A critical-severity out-of-bounds write in Firefox from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 65% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)1.1%top 35.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Mozilla developers and community members Julian Hector, Randell Jesup, Gabriele Svelto, Tyson Smith, Christian Holler, and Masayuki Nakano reported memory safety bugs present in Firefox 94. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 95, Firefox ESR < 91.4.0, and Thunderbird < 91.4.0.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20thunderbird91.4.0-r0ALPINE-CVE-2021-4129
Alpine:v3.21thunderbird91.4.0-r0ALPINE-CVE-2021-4129
Alpine:v3.22thunderbird91.4.0-r0ALPINE-CVE-2021-4129
Alpine:v3.23thunderbird91.4.0-r0ALPINE-CVE-2021-4129
Debian:12firefox-esr91.4.0esr-1DEBIAN-CVE-2021-4129
Debian:13firefox-esr91.4.0esr-1DEBIAN-CVE-2021-4129
Debian:14firefox-esr91.4.0esr-1DEBIAN-CVE-2021-4129
Debian:12thunderbird1:91.4.0-1DEBIAN-CVE-2021-4129
Debian:13thunderbird1:91.4.0-1DEBIAN-CVE-2021-4129
Debian:14thunderbird1:91.4.0-1DEBIAN-CVE-2021-4129
Rocky Linux:8firefox0:91.4.0-1.el8_5RLSA-2021:5013
Rocky Linux:8thunderbird0:91.4.0-2.el8_5RLSA-2021:5045

Affected products (as reported)

VendorProductVersions
Mozilla Firefox unspecified – before 95
Mozilla Firefox ESR unspecified – before 91.4.0
Mozilla Thunderbird unspecified – before 91.4.0

Weakness: CWE-787 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References