CVE-2021-4129
9.8
CRITICAL
CVSS 3.1
EPSS 0.36%
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.
How to fix CVE-2021-4129
To remediate CVE-2021-4129, upgrade the affected package to a fixed version below.
- —upgrade to 91.4.1esr-1~deb11u1 or later
- —upgrade to 1:91.4.1-1~deb11u1 or later
Is CVE-2021-4129 being exploited?
Low — EPSS is 0.4%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 91.4.1esr-1~deb11u1
- from 0, < 1:91.4.1-1~deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |