Buffer overflow in Mozilla Firefox and Firefox ESR - CVE-2021-43534
Published: November 2, 2021 / Updated: December 20, 2021
Vulnerability identifier: #VU57888
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-2021-43534
CWE-ID: CWE-119
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
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 webpage, 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.
Affected software
Mozilla Firefox
Firefox ESR
Ubuntu
firefox-esr (Debian package)
thunderbird (Debian package)
thunderbird (Ubuntu package)
Firefox ESR
Ubuntu
firefox-esr (Debian package)
thunderbird (Debian package)
thunderbird (Ubuntu package)
How to mitigate CVE-2021-43534
Install updates from vendor's website.
Mozilla Firefox - update to 94.0
Firefox ESR - update to 91.3.0
firefox-esr (Debian package) - update to 91.4.1esr-1~deb11u1
thunderbird (Debian package) - addressed in versions 1:91.4.1-1~deb10u1, 1:91.4.1-1~deb11u1
thunderbird (Ubuntu package) - addressed in versions 1:91.5.0+build1-0ubuntu0.18.04.1, 1:91.5.0+build1-0ubuntu0.20.04.1
Firefox ESR - update to 91.3.0
firefox-esr (Debian package) - update to 91.4.1esr-1~deb11u1
thunderbird (Debian package) - addressed in versions 1:91.4.1-1~deb10u1, 1:91.4.1-1~deb11u1
thunderbird (Ubuntu package) - addressed in versions 1:91.5.0+build1-0ubuntu0.18.04.1, 1:91.5.0+build1-0ubuntu0.20.04.1