CVE-2021-29976

HIGH

Firefox < 90.0 and Firefox ESR < 78.12 - Out-of-bounds Write

Title source: llm
STIX 2.1

Description

Mozilla developers reported memory safety bugs present in code shared between Firefox and Thunderbird. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 78.12, Firefox ESR < 78.12, and Firefox < 90.

References (6)

Core 6
Core References
Third Party Advisory vendor-advisory x_refsource_gentoo
https://security.gentoo.org/glsa/202202-03
Third Party Advisory vendor-advisory x_refsource_gentoo
https://security.gentoo.org/glsa/202208-14

Scores

CVSS v3 8.8
EPSS 0.0059
EPSS Percentile 69.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Details

CWE
CWE-787
Status published
Products (3)
mozilla/firefox < 90.0
mozilla/firefox_esr < 78.12
mozilla/thunderbird < 78.12
Published Aug 05, 2021
Tracked Since Feb 18, 2026