CVE-2021-23976

HIGH

Firefox < 86.0 - UI Spoofing and Cross-Origin Attacks via Malicious Intent Manifest

Title source: llm
STIX 2.1

Description

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.

References (3)

Core 3
Core References
Release Notes, Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-07/
Issue Tracking, Permissions Required, Vendor Advisory x_refsource_misc
https://bugzilla.mozilla.org/show_bug.cgi?id=1684627
Third Party Advisory vendor-advisory x_refsource_gentoo
https://security.gentoo.org/glsa/202104-10

Scores

CVSS v3 8.1
EPSS 0.0110
EPSS Percentile 61.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Details

CWE
CWE-1021
Status published
Products (1)
mozilla/firefox < 86.0
Published Feb 26, 2021
Tracked Since Feb 18, 2026