CVE-2020-12423

Publication date 9 July 2020

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

When the Windows DLL "webauthn.dll" was missing from the Operating System, and a malicious one was placed in a folder in the user's %PATH%, Firefox may have loaded the DLL, leading to arbitrary code execution. *Note: This issue only affects the Windows operating system; other operating systems are unaffected.* This vulnerability affects Firefox < 78.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
firefox	20.04 LTS focal	Not in release
	19.10 eoan	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not in release
thunderbird	20.04 LTS focal	Not in release
	19.10 eoan	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not in release

Notes

mdeslaur

this is a windows-specific issue

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.8 · High

Base metrics

Parameter	Value
Attack vector	Local
Attack complexity	Low
Privileges required	None
User interaction	Required
Scope	Unchanged
Confidentiality impact	High
Integrity impact	High
Availability impact	High

Scores

Parameter	Value
Base score	7.8 · High
Exploitability score	-
Impact score	-

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H