There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - Mozilla developers and community members reported memory safety bugs present in Firefox 75 and Firefox ESR
    68.7. 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. This vulnerability affects Firefox ESR < 68.8,
    Firefox < 76, and Thunderbird < 68.8.0. (CVE-2020-12395)

  - A buffer overflow could occur when parsing and validating SCTP chunks in WebRTC. This could have led to
    memory corruption and a potentially exploitable crash. This vulnerability affects Firefox ESR < 68.8,
    Firefox < 76, and Thunderbird < 68.8.0. (CVE-2020-6831)

  - A race condition when running shutdown code for Web Worker led to a use-after-free vulnerability. This
    resulted in a potentially exploitable crash. This vulnerability affects Firefox ESR < 68.8, Firefox < 76,
    and Thunderbird < 68.8.0. (CVE-2020-12387)

  - The Firefox content processes did not sufficiently lockdown access control which could result in a sandbox
    escape. *Note: this issue only affects Firefox on Windows operating systems.*. This vulnerability affects
    Firefox ESR < 68.8 and Firefox < 76. (CVE-2020-12388, CVE-2020-12389)

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Documents formed using data: URLs in an OBJECT element failed to inherit the CSP of the creating context.
    This allowed the execution of scripts that should have been blocked, albeit with a unique opaque origin.
    This vulnerability affects Firefox < 76. (CVE-2020-12391)

Note that Nessus relies on the presence of the package as reported by the vendor.

The version of Firefox installed on the remote Windows host is prior to 76.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2020-16 advisory.

  - Mozilla developers and community members Alexandru Michis, Jason Kratzer, philipp, Ted Campbell, Bas     Schouten, Andr Bargull, and Karl Tomlinson reported memory safety bugs present in Firefox 75 and Firefox     ESR 68.7. 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-2020-12395)

  - The Firefox content processes did not sufficiently lockdown access control which could result in a sandbox     escape. Note: this issue only affects Firefox on Windows operating systems. (CVE-2020-12388,     CVE-2020-12389)

  - A race condition when running shutdown code for Web Worker led to a use-after-free vulnerability. This     resulted in a potentially exploitable crash. (CVE-2020-12387)

  - A buffer overflow could occur when parsing and validating SCTP chunks in WebRTC. This could have led to     memory corruption and a potentially exploitable crash. (CVE-2020-6831)

  - Incorrect origin serialization of URLs with IPv6 addresses could lead to incorrect security checks     (CVE-2020-12390)

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

The remote Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-4353-1 advisory.

    Multiple security issues were discovered in Firefox. If a user were tricked in to opening a specially     crafted website, an attacker could potentially exploit these to cause a denial of service, bypass security     restrictions, spoof the URL bar, or execute arbitrary code. (CVE-2020-6831, CVE-2020-12387,     CVE-2020-12390, CVE-2020-12391, CVE-2020-12394, CVE-2020-12395, CVE-2020-12396)

    It was discovered that the Devtools Copy as cURL feature did not properly escape the HTTP POST     data of a request. If a user were tricked in to using the Copy as cURL feature to copy and paste a     command with specially crafted data in to a terminal, an attacker could potentially exploit this to obtain     sensitive information from local files. (CVE-2020-12392)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

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

The version of Firefox installed on the remote macOS or Mac OS X host is prior to 76.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2020-16 advisory.

  - Mozilla developers and community members Alexandru Michis, Jason Kratzer, philipp, Ted Campbell, Bas     Schouten, Andr Bargull, and Karl Tomlinson reported memory safety bugs present in Firefox 75 and Firefox     ESR 68.7. 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-2020-12395)

  - The Firefox content processes did not sufficiently lockdown access control which could result in a sandbox     escape. Note: this issue only affects Firefox on Windows operating systems. (CVE-2020-12388,     CVE-2020-12389)

  - A race condition when running shutdown code for Web Worker led to a use-after-free vulnerability. This     resulted in a potentially exploitable crash. (CVE-2020-12387)

  - A buffer overflow could occur when parsing and validating SCTP chunks in WebRTC. This could have led to     memory corruption and a potentially exploitable crash. (CVE-2020-6831)

  - Incorrect origin serialization of URLs with IPv6 addresses could lead to incorrect security checks     (CVE-2020-12390)

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

ID	Name	Product	Family	Published	Updated	Severity
404367	Alpine: multiple firefox packages: security update to 76.0-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	10/31/2023	7/6/2026	critical
426034	Alpine: multiple librewolf packages: security update to 76.0-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	5/16/2025	7/6/2026	critical
426034	Alpine: multiple librewolf packages: security update to 76.0-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	5/16/2025	7/6/2026	critical
404367	Alpine: multiple firefox packages: security update to 76.0-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	10/31/2023	7/6/2026	critical
223342	Linux Distros Unpatched Vulnerability : CVE-2020-12391	Nessus	Misc.	3/4/2025	1/5/2026	high
136404	Mozilla Firefox < 76.0	Nessus	Windows	5/7/2020	11/18/2025	critical
136420	Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS : Firefox vulnerabilities (USN-4353-1)	Nessus	Ubuntu Local Security Checks	5/8/2020	8/27/2024	critical
136403	Mozilla Firefox < 76.0	Nessus	MacOS X Local Security Checks	5/7/2020	11/18/2025	critical

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