CVE-2021-23978

moderate-risk
Published 2021-02-26

Mozilla developers reported memory safety bugs present in Firefox 85 and Firefox ESR 78.7. 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 < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.

Do I need to act?

~
1.2% chance of exploitation in next 30 days
EPSS score — moderate exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
8
CVSS 8.8/10 High
NETWORK / LOW complexity

Affected Products (5)

Affected Vendors

Debian Mozilla

References (16)

Broken Link https://bugzilla.mozilla.org/buglist.cgi?bug_id=786797%2C1682928%2C1687391%2C168...
Mailing List https://lists.debian.org/debian-lts-announce/2021/03/msg00000.html
Third Party Advisory https://security.gentoo.org/glsa/202104-09
Third Party Advisory https://security.gentoo.org/glsa/202104-10
Third Party Advisory https://www.debian.org/security/2021/dsa-4866
Release Notes https://www.mozilla.org/security/advisories/mfsa2021-07/
Release Notes https://www.mozilla.org/security/advisories/mfsa2021-08/
Release Notes https://www.mozilla.org/security/advisories/mfsa2021-09/
Broken Link https://bugzilla.mozilla.org/buglist.cgi?bug_id=786797%2C1682928%2C1687391%2C168...
Mailing List https://lists.debian.org/debian-lts-announce/2021/03/msg00000.html
Third Party Advisory https://security.gentoo.org/glsa/202104-09
Third Party Advisory https://security.gentoo.org/glsa/202104-10
Third Party Advisory https://www.debian.org/security/2021/dsa-4866
Release Notes https://www.mozilla.org/security/advisories/mfsa2021-07/
Release Notes https://www.mozilla.org/security/advisories/mfsa2021-08/
Release Notes https://www.mozilla.org/security/advisories/mfsa2021-09/
46
/ 100
moderate-risk
Severity 30/34 · Critical
Exploitability 4/34 · Minimal
Exposure 12/34 · Low