Mozilla Firefox ESR < 78.13

high Nessus Plugin ID 152414


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


The version of Firefox ESR installed on the remote Windows host is prior to 78.13. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2021-34 advisory.

- A suspected race condition when calling getaddrinfo led to memory corruption and a potentially exploitable crash. Note: This issue only affected Linux operating systems. Other operating systems are unaffected. (CVE-2021-29986)

- Firefox incorrectly treated an inline list-item element as a block element, resulting in an out of bounds read or memory corruption, and a potentially exploitable crash. (CVE-2021-29988)

- Instruction reordering resulted in a sequence of instructions that would cause an object to be incorrectly considered during garbage collection. This led to memory corruption and a potentially exploitable crash.

- Uninitialized memory in a canvas object could have caused an incorrect free() leading to memory corruption and a potentially exploitable crash. (CVE-2021-29980)

- A use-after-free vulnerability in media channels could have led to memory corruption and a potentially exploitable crash. (CVE-2021-29985)

- Mozilla developers Christoph Kerschbaumer, Simon Giesecke, Sandor Molnar, and Olli Pettay reported memory safety bugs present in Firefox 90 and Firefox ESR 78.12. 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-2021-29989)

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


Upgrade to Mozilla Firefox ESR version 78.13 or later.

See Also

Plugin Details

Severity: High

ID: 152414

File Name: mozilla_firefox_78_13_esr.nasl

Version: 1.7

Type: local

Agent: windows

Family: Windows

Published: 8/10/2021

Updated: 9/10/2021

Supported Sensors: Nessus Agent

Risk Information

CVSS Score Source: CVE-2021-29989


Risk Factor: Critical

Score: 9


Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

Temporal Vector: E:U/RL:OF/RC:C


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: E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:mozilla:firefox_esr

Required KB Items: Mozilla/Firefox/Version

Exploit Ease: No known exploits are available

Patch Publication Date: 8/10/2021

Vulnerability Publication Date: 8/10/2021

Reference Information

CVE: CVE-2021-29980, CVE-2021-29984, CVE-2021-29985, CVE-2021-29986, CVE-2021-29988, CVE-2021-29989

IAVA: 2021-A-0366-S