Auth bypass in Mozilla Firefox

CVE-2018-12399

When a new protocol handler is registered, the API accepts a title argument which can be used to mislead users about which domain is registering the new protocol. This may result in the user approving a protocol handler that they otherwise would not have. This vulnerability affects Firefox < 63.

Vulnerability class: Broken Authentication

EPSS: 0.014 (68.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2018-12399?
CVE-2018-12399 is a medium-severity vulnerability in Mozilla Firefox, classified under Improper Authentication. CVSS score: 4.3/10. Published 2019-02-28.
How severe is CVE-2018-12399?
Medium severity. CVSS v3 base score is 4.3 out of 10.