Detections
Analytics

Mozilla Firefox < 86.0

high Nessus Plugin ID 146779

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Synopsis

A web browser installed on the remote macOS or Mac OS X host is affected by multiple vulnerabilities.

Description

The version of Firefox installed on the remote macOS or Mac OS X host is prior to 86.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2021-07 advisory.

 - Mozilla developers Tyson Smith, Lars T Hansen, Valentin Gosu, and Sebastian Hengst reported memory safety bugs present in Firefox 85. 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-2021-23979)

 - As specified in the W3C Content Security Policy draft, when creating a violation report, User agents need to ensure that the source file is the URL requested by the page, pre-redirects. If thats not possible, user agents need to strip the URL down to an origin to avoid unintentional leakage. Under certain types of redirects, Firefox incorrectly set the source file to be the destination of the redirects. This was fixed to be the redirect destination's origin. (CVE-2021-23969)

 - Context-specific code was included in a shared jump table; resulting in assertions being triggered in multithreaded wasm code. (CVE-2021-23970)

 - If Content Security Policy blocked frame navigation, the full destination of a redirect served in the frame was reported in the violation report; as opposed to the original frame URI. This could be used to leak sensitive information contained in such URIs. (CVE-2021-23968)

 - The DOMParser API did not properly process <code><noscript></code> elements for escaping. This could be used as an mXSS vector to bypass an HTML Sanitizer. (CVE-2021-23974)

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 86.0 or later.

See Also

https://www.mozilla.org/en-US/security/advisories/mfsa2021-07/

Plugin Details

Severity: High

ID: 146779

File Name: macos_firefox_86_0.nasl

Version: 1.8

Type: local

Agent: macosx

Published: 2/23/2021

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: 6.7

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-2021-23979

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: 2/23/2021

Vulnerability Publication Date: 2/23/2021

Reference Information

CVE: CVE-2021-23968, CVE-2021-23969, CVE-2021-23970, CVE-2021-23971, CVE-2021-23972, CVE-2021-23973, CVE-2021-23974, CVE-2021-23975, CVE-2021-23976, CVE-2021-23977, CVE-2021-23978, CVE-2021-23979

IAVA: 2021-A-0107-S