Mozilla Firefox < 92.0

high Nessus Plugin ID 153089

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Synopsis

A web browser installed on the remote Windows host is affected by multiple vulnerabilities.

Description

The version of Firefox installed on the remote Windows host is prior to 92.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2021-38 advisory.

- Mozilla developers Christian Holler and Lars T Hansen reported memory safety bugs present in Firefox 91.
Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. (CVE-2021-38494)

- Firefox for Android allowed navigations through the `intent://` protocol, which could be used to cause crashes and UI spoofs. This bug only affects Firefox for Android. Other operating systems are unaffected.
(CVE-2021-29993)

- Mixed-content checks were unable to analyze opaque origins which led to some mixed content being loaded.
(CVE-2021-38491)

- When delegating navigations to the operating system, Firefox would accept the `mk` scheme which might allow attackers to launch pages and execute scripts in Internet Explorer in unprivileged mode. This bug only affects Firefox for Windows. Other operating systems are unaffected. (CVE-2021-38492)

- If a domain name contained a RTL character, it would cause the domain to be rendered to the right of the path. This could lead to user confusion and spoofing attacks. This bug only affects Firefox for Android.
Other operating systems are unaffected. Note: Due to a clerical error this advisory was not included in the original announcement, and was added in Feburary 2022. (CVE-2021-4221)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Upgrade to Mozilla Firefox version 92.0 or later.

Plugin Details

Severity: High

ID: 153089

File Name: mozilla_firefox_92_0.nasl

Version: 1.8

Type: local

Agent: windows

Family: Windows

Published: 9/7/2021

Updated: 11/18/2025

Supported Sensors: Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.3

Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-2021-38494

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:mozilla:firefox

Required KB Items: installed_sw/Mozilla Firefox

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 9/7/2021

Vulnerability Publication Date: 9/7/2021

Reference Information

CVE: CVE-2021-29993, CVE-2021-38491, CVE-2021-38492, CVE-2021-38493, CVE-2021-38494, CVE-2021-4221

IAVA: 2021-A-0405-S

Detections

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