Mozilla developers reported memory safety and script safety bugs present in Firefox 73. Some of these bugs showed evidence of memory corruption or escalation of privilege and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 74.

The remote Ubuntu 16.04 LTS / 18.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-4299-1 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, spoof the URL     or other browser chrome, obtain sensitive information, bypass Content Security Policy (CSP) protections,     or execute arbitrary code. (CVE-2019-20503, CVE-2020-6805, CVE-2020-6806, CVE-2020-6807, CVE-2020-6808,     CVE-2020-6810, CVE-2020-6812, CVE-2020-6813, CVE-2020-6814, CVE-2020-6815)

    It was discovered that Web Extensions with the all-url permission could access local files. If a user were     tricked in to installing a specially crafted extension, an attacker could potentially exploit this to     obtain sensitive information. (CVE-2020-6809)

    It was discovered that the Devtools' 'Copy as cURL' feature did not fully escape website-controlled data.
    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 execute arbitrary commands     via command injection. (CVE-2020-6811)

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 Windows host is prior to 74.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2020-08 advisory. Note that Nessus has not tested for this issue 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 74.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2020-08 advisory. Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
134442	Ubuntu 16.04 LTS / 18.04 LTS : Firefox vulnerabilities (USN-4299-1)	Nessus	Ubuntu Local Security Checks	critical
134405	Mozilla Firefox < 74.0 Multiple Vulnerabilities	Nessus	Windows	critical
134404	Mozilla Firefox < 74.0 Multiple Vulnerabilities	Nessus	MacOS X Local Security Checks	critical

Detections

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CVE-2020-6815

critical

Tenable Plugins

critical

critical

critical