CVE-2021-29961

MEDIUM

Firefox < 89.0 - User Interface Spoofing via Oversized Select Element

Title source: llm
STIX 2.1

Description

When styling and rendering an oversized `<select>` element, Firefox did not apply correct clipping which allowed an attacker to paint over the user interface. This vulnerability affects Firefox < 89.

References (3)

Core 3
Core References
Release Notes, Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-23/
Broken Link, Issue Tracking, Vendor Advisory x_refsource_misc
https://bugzilla.mozilla.org/show_bug.cgi?id=1700235
Third Party Advisory vendor-advisory x_refsource_gentoo
https://security.gentoo.org/glsa/202107-09

Scores

CVSS v3 4.3
EPSS 0.0032
EPSS Percentile 54.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Details

CWE
CWE-863
Status published
Products (1)
mozilla/firefox 78.11.0 - 89.0
Published Jun 24, 2021
Tracked Since Feb 18, 2026