XSS in Mozilla Firefox

CVE-2020-12404

For native-to-JS bridging the app requires a unique token to be passed that ensures non-app code can't call the bridging functions. That token could leak when used for downloading files. This vulnerability affects Firefox for iOS < 26.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.008 (52.3th 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:L/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2020-12404?
CVE-2020-12404 is a medium-severity vulnerability in Mozilla Firefox, classified under Cross-site Scripting. CVSS score: 4.3/10. Published 2020-07-09.
How severe is CVE-2020-12404?
Medium severity. CVSS v3 base score is 4.3 out of 10.