Spoofing attack in Mozilla Firefox - CVE-2020-12409
Published: June 3, 2020 / Updated: July 15, 2020
Vulnerability identifier: #VU28533
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-2020-12409
CWE-ID: CWE-451
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform spoofing attack.
The vulnerability exists due to incorrect processing of certain blank characters in URL in unicode that were rendered as space instead of an encoded URL. A remote attacker can use a specially crafted URL to spoof page content of legitimate website.
Affected software
Mozilla Firefox
Arch Linux
Gentoo Linux
firefox (Alpine package)
Arch Linux
Gentoo Linux
firefox (Alpine package)
How to mitigate CVE-2020-12409
Install updates from vendor's website.
Mozilla Firefox - update to 77.0
firefox (Alpine package) - update to 77.0-r0
firefox (Alpine package) - update to 77.0-r0