CVE-2021-29964

HIGH

Firefox <89 - Buffer Overflow

Title source: llm
STIX 2.1

Description

A locally-installed hostile program could send `WM_COPYDATA` messages that Firefox would process incorrectly, leading to an out-of-bounds read. *This bug only affects Firefox on Windows. Other operating systems are unaffected.*. This vulnerability affects Thunderbird < 78.11, Firefox < 89, and Firefox ESR < 78.11.

References (4)

Core 4
Core References
Release Notes, Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-26/
Release Notes, Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-24/
Release Notes, Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-23/
Permissions Required, Vendor Advisory x_refsource_misc
https://bugzilla.mozilla.org/show_bug.cgi?id=1706501

Scores

CVSS v3 7.1
EPSS 0.0032
EPSS Percentile 55.4%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H

Details

CWE
CWE-125
Status published
Products (3)
mozilla/firefox < 89.0
mozilla/firefox_esr < 78.11
mozilla/thunderbird < 78.11
Published Jun 24, 2021
Tracked Since Feb 18, 2026