CVE-2021-43534

moderate-risk
Published 2021-12-08

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.

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 Vendors

47
/ 100
moderate-risk
Severity 30/34 · Critical
Exploitability 4/34 · Minimal
Exposure 13/34 · Low