CVE-2021-23973

MEDIUM

Firefox < 86.0, Firefox ESR < 78.8, Thunderbird < 78.8 - Information Disclosure via Cross-Origin Media Decoding Error

Title source: llm
STIX 2.1

Description

When trying to load a cross-origin resource in an audio/video context a decoding error may have resulted, and the content of that error may have revealed information about the resource. This vulnerability affects Firefox < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.

References (8)

Core 8
Core References
Release Notes, Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-07/
Release Notes, Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-09/
Release Notes, Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-08/
Issue Tracking, Permissions Required, Vendor Advisory x_refsource_misc
https://bugzilla.mozilla.org/show_bug.cgi?id=1690976
Mailing List, Third Party Advisory mailing-list x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2021/03/msg00000.html
Third Party Advisory vendor-advisory x_refsource_debian
https://www.debian.org/security/2021/dsa-4866
Third Party Advisory vendor-advisory x_refsource_gentoo
https://security.gentoo.org/glsa/202104-10
Third Party Advisory vendor-advisory x_refsource_gentoo
https://security.gentoo.org/glsa/202104-09

Scores

CVSS v3 6.5
EPSS 0.0053
EPSS Percentile 67.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Details

CWE
CWE-209
Status published
Products (5)
debian/debian_linux 9.0
debian/debian_linux 10.0
mozilla/firefox < 86.0
mozilla/firefox_esr < 78.8
mozilla/thunderbird < 78.8
Published Feb 26, 2021
Tracked Since Feb 18, 2026