Security restrictions bypass in Mozilla Firefox - CVE-2021-29974
Published: July 13, 2021
Vulnerability identifier: #VU54683
CSH Severity: Medium
CVSS v4 BT: 1.2 [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/E:U/U:Green]
CVE-ID: CVE-2021-29974
CWE-ID: CWE-264
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 application allows to override HSTS error, when network partitioning was enabled. As a result of Enhanced Tracking Protection settings, a TLS error page would allow the user to override an error on a domain which had specified HTTP Strict Transport Security.
Affected software
Mozilla Firefox
Arch Linux
Gentoo Linux
Ubuntu
firefox (Ubuntu package)
Arch Linux
Gentoo Linux
Ubuntu
firefox (Ubuntu package)
How to mitigate CVE-2021-29974
Install updates from vendor's website.
Mozilla Firefox - update to 90.0
firefox (Ubuntu package) - addressed in versions 90.0+build1-0ubuntu0.18.04.1, 90.0+build1-0ubuntu0.20.04.1, 90.0+build1-0ubuntu0.20.10.1, 90.0+build1-0ubuntu0.21.04.1
firefox (Ubuntu package) - addressed in versions 90.0+build1-0ubuntu0.18.04.1, 90.0+build1-0ubuntu0.20.04.1, 90.0+build1-0ubuntu0.20.10.1, 90.0+build1-0ubuntu0.21.04.1