Description
Mozilla developers and community members reported memory safety bugs present in Firefox 93 and Firefox ESR 91.2. 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 < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.
References (8)
Core 8
Core References
Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-49/
Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-50/
Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-48/
Broken Link, Issue Tracking, Vendor Advisory x_refsource_misc
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1606864%2C1712671%2C1730048%2C1735152
Third Party Advisory vendor-advisory
x_refsource_debian
https://www.debian.org/security/2021/dsa-5026
Mailing List, Third Party Advisory mailing-list
x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html
Issue Tracking, Third Party Advisory vendor-advisory
x_refsource_debian
https://www.debian.org/security/2022/dsa-5034
Mailing List, Third Party Advisory mailing-list
x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html
Scores
CVSS v3
8.8
EPSS
0.0119
EPSS Percentile
79.1%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Details
CWE
CWE-787
Status
published
Products (6)
debian/debian_linux
9.0
debian/debian_linux
10.0
debian/debian_linux
11.0
mozilla/firefox
< 94.0
mozilla/firefox_esr
< 91.3.0
mozilla/thunderbird
< 91.3.0
Published
Dec 08, 2021
Tracked Since
Feb 18, 2026