Spoofing attack in Mozilla Firefox - CVE-2020-26979

Vulnerability identifier: #VU49021

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-2020-26979

CWE-ID: CWE-451

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exists due to the way Firefox processes events, related to URL processing in the address bar. When a user typed a URL in the address bar or the search bar and quickly hit the enter key, a website could sometimes capture that event and then redirect the user before navigation occurred to the desired, entered address. To construct a convincing spoof the attacker would have had to guess what the user was typing, perhaps by suggesting it.

Mozilla Firefox
Arch Linux
Ubuntu
openEuler
firefox (Alpine package)
firefox
firefox-debuginfo
firefox-debugsource
mozilla-crashreporter-firefox-debuginfo
firefox (Ubuntu package)

Install updates from vendor's website.

Mozilla Firefox - update to 84.0
firefox (Alpine package) - update to 84.0.1-r0
firefox - update to 79.0-32
firefox-debuginfo - update to 79.0-32
firefox-debugsource - update to 79.0-32
mozilla-crashreporter-firefox-debuginfo - update to 79.0-32
firefox (Ubuntu package) - addressed in versions 84.0+build3-0ubuntu0.16.04.1, 84.0+build3-0ubuntu0.18.04.1, 84.0+build3-0ubuntu0.20.04.1, 84.0+build3-0ubuntu0.20.10.1

• https://www.mozilla.org/en-US/security/advisories/mfsa2020-54/

• Multiple vulnerabilities in Mozilla Firefox and Firefox ESR
• Arch Linux update for firefox
• Spoofing attack in firefox (Alpine package)
• openEuler 20.03 LTS SP4 update for firefox
• Ubuntu update for firefox