Vulnerability in Mozilla Firefox

CVE-2021-29974

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.

EPSS: 0.008 (54.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.

Affected products

References

Frequently asked questions

What is CVE-2021-29974?
CVE-2021-29974 is a medium-severity vulnerability in Mozilla Firefox. CVSS score: 4.3/10. Published 2021-08-05.
How severe is CVE-2021-29974?
Medium severity. CVSS v3 base score is 4.3 out of 10.