#VU50024 Buffer overflow in Mozilla Firefox and Firefox ESR - CVE-2021-23960

Vulnerability identifier: #VU50024

Vulnerability risk: High

CVSSv4.0: 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/E:U/U:Amber

CVE-ID: CVE-2021-23960

CWE-ID: CWE-119

Exploitation vector: Remote access

Exploit availability: No public exploit available

Vulnerable software:
Mozilla Firefox
Firefox ESR

Software vendor:
Mozilla

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

The vulnerability exists due to insufficient validation of user-supplied input when performing garbage collection on re-declared JavaScript variables. A remote attacker can create a specially crafted web page, trick the victim into opening it and execute arbitrary code on the system.

Install updates from vendor's website.

• https://www.mozilla.org/en-US/security/advisories/mfsa2021-03/
• https://www.mozilla.org/en-US/security/advisories/mfsa2021-04/