Mozilla Firefox < 115.5

high Nessus Plugin ID 186032


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


The version of Firefox installed on the remote Windows host is prior to 115.5. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2023-50 advisory.

- On some systemsdepending on the graphics settings and driversit was possible to force an out-of-bounds read and leak memory data into the images created on the canvas element. (CVE-2023-6204)

- It was possible to cause the use of a MessagePort after it had already been freed, which could potentially have led to an exploitable crash. (CVE-2023-6205)

- The black fade animation when exiting fullscreen is roughly the length of the anti-clickjacking delay on permission prompts. It was possible to use this fact to surprise users by luring them to click where the permission grant button would be about to appear. (CVE-2023-6206)

- Ownership mismanagement led to a use-after-free in ReadableByteStreams (CVE-2023-6207)

- When using X11, text selected by the page using the Selection API was erroneously copied into the primary selection, a temporary storage not unlike the clipboard. This bug only affects Firefox on X11. Other systems are unaffected. (CVE-2023-6208)

- Relative URLs starting with three slashes were incorrectly parsed, and a path-traversal /../ part in the path could be used to override the specified host. This could contribute to security problems in web sites. (CVE-2023-6209)

- Memory safety bugs present in Firefox 119, Firefox ESR 115.4, and Thunderbird 115.4. 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-2023-6212)

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


Upgrade to Mozilla Firefox version 115.5 or later.

See Also

Plugin Details

Severity: High

ID: 186032

File Name: mozilla_firefox_115_5.nasl

Version: 1.3

Type: local

Agent: windows

Family: Windows

Published: 11/21/2023

Updated: 12/22/2023

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

Risk Information


Risk Factor: Medium

Score: 6.7


Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

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

CVSS Score Source: CVE-2023-6212


Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

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:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:mozilla:firefox

Required KB Items: Mozilla/Firefox/Version

Exploit Ease: No known exploits are available

Patch Publication Date: 11/21/2023

Vulnerability Publication Date: 11/21/2023

Reference Information

CVE: CVE-2023-6204, CVE-2023-6205, CVE-2023-6206, CVE-2023-6207, CVE-2023-6208, CVE-2023-6209, CVE-2023-6212

IAVA: 2023-A-0654-S