CVE-2021-29974

4.3 mediumEPSS 0.8%

Medium (4.3) in mozilla firefox. EPSS 0.8% chance of exploitation in the next 30 days.

When network partitioning was enabled, e.g. as a result of Enhanced Tracking Protection settings, a TLS error page would allow the user to override an error on a domain which had specified HTTP Strict Transport Security (which implies that the error should not be override-able.) This issue did not affect the network connections, and they were correctly upgraded to HTTPS automatically. This vulnerability affects Firefox < 90.

Severity

CVSS 3.1

4.3 medium

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

EPSS: 0.8% chance of exploitation in the next 30 days; higher than 57% of CVEs (scores of 2026-10-31)
Published: 2021-08-05
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

mozilla:firefox

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1704843
https://security.gentoo.org/glsa/202202-03
https://www.mozilla.org/security/advisories/mfsa2021-28/
https://bugzilla.mozilla.org/show_bug.cgi?id=1704843
https://security.gentoo.org/glsa/202202-03

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