Reachable Assertion in Mozilla Firefox - CVE-2021-23970
Published: February 23, 2021
Vulnerability identifier: #VU50880
CSH Severity: Medium
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-23970
CWE-ID: CWE-617
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to a reachable assertion in multithreaded wasm code, when validating separation of script domains. A remote attacker can create a specially crafted web page, trick the victim into visiting it, trigger an assertion failure and bypass implemented security restrictions.
Affected software
Mozilla Firefox
Gentoo Linux
Ubuntu
firefox (Ubuntu package)
Gentoo Linux
Ubuntu
firefox (Ubuntu package)
How to mitigate CVE-2021-23970
Install updates from vendor's website.
Mozilla Firefox - update to 86.0
firefox (Ubuntu package) - addressed in versions 86.0+build3-0ubuntu0.16.04.1, 86.0+build3-0ubuntu0.18.04.1, 86.0+build3-0ubuntu0.20.04.1, 86.0+build3-0ubuntu0.20.10.1
firefox (Ubuntu package) - addressed in versions 86.0+build3-0ubuntu0.16.04.1, 86.0+build3-0ubuntu0.18.04.1, 86.0+build3-0ubuntu0.20.04.1, 86.0+build3-0ubuntu0.20.10.1