Security features bypass in Mozilla Firefox - CVE-2021-23971
Published: February 23, 2021
Vulnerability identifier: #VU50883
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-23971
CWE-ID: CWE-254
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to gain access to sensitive information.
The vulnerability exists due to an error when processing a redirect with a conflicting Referrer-Policy. The browser adopts redirect's Referrer-Policy, which may result in disclosure of more information than intended by the original origin.
Affected software
Mozilla Firefox
Gentoo Linux
Ubuntu
firefox (Ubuntu package)
Gentoo Linux
Ubuntu
firefox (Ubuntu package)
How to mitigate CVE-2021-23971
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