Vulnerability in Mozilla Firefox

CVE-2021-23976

When accepting a malicious intent from other installed apps, Firefox for Android accepted manifests from arbitrary file paths and allowed declaring webapp manifests for other origins. This could be used to gain fullscreen access for UI spoofing and could also lead to cross-origin attacks on targeted websites. Note: This issue is a different issue from CVE-2020-26954 and only affected Firefox for Android. Other operating systems are unaffected. This vulnerability affects Firefox < 86.

EPSS: 0.011 (62.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-23976?
CVE-2021-23976 is a high-severity vulnerability in Mozilla Firefox, classified under Improper Restriction of Rendered UI Layers or Frames (Clickjacking). CVSS score: 8.1/10. Published 2021-02-26.
How severe is CVE-2021-23976?
High severity. CVSS v3 base score is 8.1 out of 10.