Buffer overflow in Mozilla Firefox and Firefox ESR - CVE-2021-4129

Vulnerability identifier: #VU58617

CSH Severity: High

CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2021-4129

CWE-ID: CWE-119

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error when processing HTML content. A remote attacker can create a specially crafted website, trick the victim into opening it, trigger memory corruption and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mozilla Firefox
Firefox ESR
Gentoo Linux
Ubuntu
Mozilla Thunderbird
thunderbird (Ubuntu package)
mail-client/thunderbird
mail-client/thunderbird-bin

Install updates from vendor's website.

Mozilla Firefox - update to 95.0
Firefox ESR - update to 91.4.0
Mozilla Thunderbird - update to 91.4.0
thunderbird (Ubuntu package) - addressed in versions 1:91.5.0+build1-0ubuntu0.18.04.1, 1:91.5.0+build1-0ubuntu0.20.04.1, 1:91.5.0+build1-0ubuntu0.21.10.1
mail-client/thunderbird - update to 91.12.0
mail-client/thunderbird-bin - update to 91.12.0

• https://www.mozilla.org/en-US/security/advisories/mfsa2021-52/
• https://www.mozilla.org/en-US/security/advisories/mfsa2021-53/

• Multiple vulnerabilities in Mozilla Firefox
• Multiple vulnerabilities in Mozilla Thunderbird
• Gentoo update for Mozilla Firefox
• Gentoo update for Mozilla Thunderbird
• Ubuntu update for thunderbird
• Ubuntu update for thunderbird