critical
CVE-2021-4129
Mozilla: Memory safety bugs fixed in Firefox 95 and Firefox ESR 91.4
In the Trivy database since at least 24 Oct 2026, 07:11 UTCWhen it arrived before that build is not recorded.
Severity by source
NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Red Hat9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Trivy's own label is CRITICAL. Rated critical by NVD. Rated lower by Red Hat (high), Amazon (high), Rocky Linux (high), Ubuntu (low).
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 and fixed versions
| Source | Package | Fixed in |
|---|---|---|
| alpine 3.16 | thunderbird | 91.4.0-r0 |
| alpine 3.17 | thunderbird | 91.4.0-r0 |
| alpine 3.18 | thunderbird | 91.4.0-r0 |
| alpine 3.19 | thunderbird | 91.4.0-r0 |
| alpine 3.20 | thunderbird | 91.4.0-r0 |
| alpine 3.21 | thunderbird | 91.4.0-r0 |
| alpine 3.22 | thunderbird | 91.4.0-r0 |
| alpine 3.23 | thunderbird | 91.4.0-r0 |
| amazon linux 2 | thunderbird, thunderbird-debuginfo | 102.7.1-1.amzn2.0.1 |
| debian 10 | thunderbird | 1:91.4.1-1~deb10u1 |
| debian 11 | firefox-esr, thunderbird | 91.4.1esr-1~deb11u1 and 1 more |
| debian 12 | firefox-esr, thunderbird | 91.4.0esr-1 and 1 more |
Show all 31 entries from 23 sources
| Source | Package | Fixed in |
|---|---|---|
| alpine 3.16 | thunderbird | 91.4.0-r0 |
| alpine 3.17 | thunderbird | 91.4.0-r0 |
| alpine 3.18 | thunderbird | 91.4.0-r0 |
| alpine 3.19 | thunderbird | 91.4.0-r0 |
| alpine 3.20 | thunderbird | 91.4.0-r0 |
| alpine 3.21 | thunderbird | 91.4.0-r0 |
| alpine 3.22 | thunderbird | 91.4.0-r0 |
| alpine 3.23 | thunderbird | 91.4.0-r0 |
| amazon linux 2 | thunderbird | 102.7.1-1.amzn2.0.1 |
| amazon linux 2 | thunderbird-debuginfo | 102.7.1-1.amzn2.0.1 |
| debian 10 | thunderbird | 1:91.4.1-1~deb10u1 |
| debian 11 | firefox-esr | 91.4.1esr-1~deb11u1 |
| debian 11 | thunderbird | 1:91.4.1-1~deb11u1 |
| debian 12 | firefox-esr | 91.4.0esr-1 |
| debian 12 | thunderbird | 1:91.4.0-1 |
| debian 13 | firefox-esr | 91.4.0esr-1 |
| debian 13 | thunderbird | 1:91.4.0-1 |
| debian 14 | firefox-esr | 91.4.0esr-1 |
| debian 14 | thunderbird | 1:91.4.0-1 |
| echo | firefox-esr | 91.4.0esr-1 |
| echo | thunderbird | 1:91.4.0-1 |
| Red Hat | firefox | no fix listed |
| Red Hat | thunderbird | no fix listed |
| rocky 8 | firefox | 91.4.0-1.el8_5 |
| rocky 8 | thunderbird | 91.4.0-2.el8_5 |
| ubuntu 18.04 | thunderbird | 1:91.5.0+build1-0ubuntu0.18.04.1 |
| ubuntu 20.04 | thunderbird | 1:91.5.0+build1-0ubuntu0.20.04.1 |
| ubuntu 21.10 | thunderbird | 1:91.5.0+build1-0ubuntu0.21.10.1 |
| ubuntu 22.04 | thunderbird | 1:91.4.0+build1-0ubuntu1 |
| ubuntu 22.10 | thunderbird | 1:91.4.0+build1-0ubuntu1 |
| ubuntu 23.04 | thunderbird | 1:91.4.0+build1-0ubuntu1 |
References
- https://access.redhat.com/errata/RHSA-2021:5045
- https://access.redhat.com/security/cve/CVE-2021-4129
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1393362%2C1736046%2C1736751%2C1737009%2C1739372%2C1739421
- https://bugzilla.redhat.com/show_bug.cgi?id=2030105
- https://bugzilla.redhat.com/show_bug.cgi?id=2030106
- https://bugzilla.redhat.com/show_bug.cgi?id=2030109
- https://bugzilla.redhat.com/show_bug.cgi?id=2030110
- https://bugzilla.redhat.com/show_bug.cgi?id=2030111
All 36 references
- https://bugzilla.redhat.com/show_bug.cgi?id=2030112
- https://bugzilla.redhat.com/show_bug.cgi?id=2030113
- https://bugzilla.redhat.com/show_bug.cgi?id=2030114
- https://bugzilla.redhat.com/show_bug.cgi?id=2030115
- https://bugzilla.redhat.com/show_bug.cgi?id=2030116
- https://bugzilla.redhat.com/show_bug.cgi?id=2030137
- https://creativecommons.org/licenses/by/4.0/
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-4129
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43528
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43536
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43537
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43538
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43539
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43541
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43542
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43543
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43545
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43546
- https://errata.rockylinux.org/RLSA-2021:5045
- https://nvd.nist.gov/vuln/detail/CVE-2021-4129
- https://ubuntu.com/security/notices/USN-5246-1
- https://ubuntu.com/security/notices/USN-5248-1
- https://www.cve.org/CVERecord?id=CVE-2021-4129
- https://www.mozilla.org/en-US/security/advisories/mfsa2021-53/#CVE-2021-4129
- https://www.mozilla.org/en-US/security/advisories/mfsa2021-54/#CVE-2021-4129
- https://www.mozilla.org/security/advisories/mfsa2021-52/
- https://www.mozilla.org/security/advisories/mfsa2021-53/
- https://www.mozilla.org/security/advisories/mfsa2021-54/