When processing a MAR update file, after the signature has been validated, an invalid name length could result in a heap overflow, leading to memory corruption and potentially arbitrary code execution. Within Firefox as released by Mozilla, this issue is only exploitable with the Mozilla-controlled signing key. This vulnerability affects Firefox < 80.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-090053 advisory.

    When processing a MAR update file, after the signature has been validated, an invalid name length could     result in a heap overflow, leading to memory corruption and potentially arbitrary code execution. Within     Firefox as released by Mozilla, this issue is only exploitable with the Mozilla-controlled signing key.
    This vulnerability affects Firefox < 80.

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

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

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

  - When processing a MAR update file, after the signature has been validated, an invalid name length could     result in a heap overflow, leading to memory corruption and potentially arbitrary code execution. Within     Firefox as released by Mozilla, this issue is only exploitable with the Mozilla-controlled signing key.
    This vulnerability affects Firefox < 80. (CVE-2020-15667)

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

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

  - If Firefox is installed to a user-writable directory, the Mozilla Maintenance Service would execute
    updater.exe from the install location with system privileges. Although the Mozilla Maintenance Service
    does ensure that updater.exe is signed by Mozilla, the version could have been rolled back to a previous
    version which would have allowed exploitation of an older bug and arbitrary code execution with System
    Privileges. *Note: This issue only affected Windows operating systems. Other operating systems are
    unaffected.*. This vulnerability affects Firefox < 80, Thunderbird < 78.2, Thunderbird < 68.12, Firefox
    ESR < 68.12, and Firefox ESR < 78.2. (CVE-2020-15663)

  - When performing EC scalar point multiplication, the wNAF point multiplication algorithm was used; which
    leaked partial information about the nonce used during signature generation. Given an electro-magnetic
    trace of a few signature generations, the private key could have been computed. This vulnerability affects
    Firefox < 80 and Firefox for Android < 80. (CVE-2020-6829)

  - When converting coordinates from projective to affine, the modular inversion was not performed in constant
    time, resulting in a possible timing-based side channel attack. This vulnerability affects Firefox < 80
    and Firefox for Android < 80. (CVE-2020-12400)

  - During ECDSA signature generation, padding applied in the nonce designed to ensure constant-time scalar
    multiplication was removed, resulting in variable-time execution dependent on secret data. This
    vulnerability affects Firefox < 80 and Firefox for Android < 80. (CVE-2020-12401)

The version of Firefox installed on the remote Windows host is prior to 80.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2020-36 advisory.

  - Mozilla developers Jason Kratzer, Christian Holler, and Byron Campen reported memory safety bugs present     in Firefox 79 and Firefox ESR 78.1. 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-2020-15670)

  - If Firefox is installed to a user-writable directory, the Mozilla Maintenance Service would execute     updater.exe from the install location with administrative privileges. Although the Mozilla Maintenance     Service does ensure that updater.exe is signed by Mozilla, the version could have been rolled back to a     previous version which would have allowed exploitation of an older bug and arbitrary code execution with     system privileges. Note: This issue only affected Windows operating systems. Other operating systems are     unaffected. (CVE-2020-15663)

  - By holding a reference to the <code>eval()</code> function from an about:blank window, a malicious webpage     could have gained access to the InstallTrigger object which would allow them to prompt the user to install     an extension. Combined with user confusion, this could result in an unintended or malicious extension     being installed. (CVE-2020-15664)

  - During ECDSA signature generation, padding applied in the nonce designed to ensure constant-time scalar     multiplication was removed, resulting in variable-time execution dependent on secret data.
    (CVE-2020-12401)

  - When performing EC scalar point multiplication, the wNAF point multiplication algorithm was used; which     leaked partial information about the nonce used during signature generation. Given an electro-magnetic     trace of a few signature generations, the private key could have been computed. (CVE-2020-6829)

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 80.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2020-36 advisory.

  - Mozilla developers Jason Kratzer, Christian Holler, and Byron Campen reported memory safety bugs present     in Firefox 79 and Firefox ESR 78.1. 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-2020-15670)

  - If Firefox is installed to a user-writable directory, the Mozilla Maintenance Service would execute     updater.exe from the install location with administrative privileges. Although the Mozilla Maintenance     Service does ensure that updater.exe is signed by Mozilla, the version could have been rolled back to a     previous version which would have allowed exploitation of an older bug and arbitrary code execution with     system privileges. Note: This issue only affected Windows operating systems. Other operating systems are     unaffected. (CVE-2020-15663)

  - By holding a reference to the <code>eval()</code> function from an about:blank window, a malicious webpage     could have gained access to the InstallTrigger object which would allow them to prompt the user to install     an extension. Combined with user confusion, this could result in an unintended or malicious extension     being installed. (CVE-2020-15664)

  - During ECDSA signature generation, padding applied in the nonce designed to ensure constant-time scalar     multiplication was removed, resulting in variable-time execution dependent on secret data.
    (CVE-2020-12401)

  - When performing EC scalar point multiplication, the wNAF point multiplication algorithm was used; which     leaked partial information about the nonce used during signature generation. Given an electro-magnetic     trace of a few signature generations, the private key could have been computed. (CVE-2020-6829)

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	Type	Severity
348825	Unity Linux 20.1050e / 20.1060e / 20.1070e Security Update: firefox (UTSA-2026-090053)	Nessus	Unity Linux Local Security Checks	Local	high
245670	Linux Distros Unpatched Vulnerability : CVE-2020-15667	Nessus	Misc.	Local	high
426892	Alpine: multiple librewolf packages: security update to 80.0-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	Local	high
426892	Alpine: multiple librewolf packages: security update to 80.0-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	Local	high
404371	Alpine: multiple firefox packages: security update to 80.0-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	Local	high
404371	Alpine: multiple firefox packages: security update to 80.0-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	Local	high
139789	Mozilla Firefox < 80.0	Nessus	Windows	Local	high
139788	Mozilla Firefox < 80.0	Nessus	MacOS X Local Security Checks	Local	high

Detections

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CVE-2020-15667

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Tenable Plugins

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