When protecting CSS blocks with the nonce feature of Content Security Policy, the @import statement in the CSS block could allow an attacker to inject arbitrary styles, bypassing the intent of the Content Security Policy. This vulnerability affects Firefox < 74.

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

  - 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.
    (CVE-2020-6815)

  - usrsctp before 2019-12-20 has out-of-bounds reads in sctp_load_addresses_from_init. (CVE-2019-20503)

  - When removing data about an origin whose tab was recently closed, a use-after-free could occur in the
    Quota manager, resulting in a potentially exploitable crash. This vulnerability affects Thunderbird <
    68.6, Firefox < 74, Firefox < ESR68.6, and Firefox ESR < 68.6. (CVE-2020-6805)

  - By carefully crafting promise resolutions, it was possible to cause an out-of-bounds read off the end of
    an array resized during script execution. This could have led to memory corruption and a potentially
    exploitable crash. This vulnerability affects Thunderbird < 68.6, Firefox < 74, Firefox < ESR68.6, and
    Firefox ESR < 68.6. (CVE-2020-6806)

  - When a device was changed while a stream was about to be destroyed, the <code>stream-reinit</code> task
    may have been executed after the stream was destroyed, causing a use-after-free and a potentially
    exploitable crash. This vulnerability affects Thunderbird < 68.6, Firefox < 74, Firefox < ESR68.6, and
    Firefox ESR < 68.6. (CVE-2020-6807)

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

  - When protecting CSS blocks with the nonce feature of Content Security Policy, the @import statement in the     CSS block could allow an attacker to inject arbitrary styles, bypassing the intent of the Content Security     Policy. This vulnerability affects Firefox < 74. (CVE-2020-6813)

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

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.

  - Mozilla developers Jason Kratzer, Boris Zbarsky, Tyson Smith, and Alexandru Michis 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. (CVE-2020-6815)

  - When removing data about an origin whose tab was recently closed, a use-after-free could occur in the     Quota manager, resulting in a potentially exploitable crash. (CVE-2020-6805)

  - By carefully crafting promise resolutions, it was possible to cause an out-of-bounds read off the end of     an array resized during script execution. This could have led to memory corruption and a potentially     exploitable crash. (CVE-2020-6806)

  - When a device was changed while a stream was about to be destroyed, the <code>stream-reinit</code> task     may have been executed after the stream was destroyed, causing a use-after-free and a potentially     exploitable crash. (CVE-2020-6807)

  - When a JavaScript URL (javascript:) is evaluated and the result is a string, this string is parsed to     create an HTML document, which is then presented. Previously, this document's URL (as reported by the     document.location property, for example) was the originating javascript: URL which could lead to spoofing     attacks; it is now correctly the URL of the originating document. (CVE-2020-6808)

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 74.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2020-08 advisory.

  - Mozilla developers Jason Kratzer, Boris Zbarsky, Tyson Smith, and Alexandru Michis 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. (CVE-2020-6815)

  - When removing data about an origin whose tab was recently closed, a use-after-free could occur in the     Quota manager, resulting in a potentially exploitable crash. (CVE-2020-6805)

  - By carefully crafting promise resolutions, it was possible to cause an out-of-bounds read off the end of     an array resized during script execution. This could have led to memory corruption and a potentially     exploitable crash. (CVE-2020-6806)

  - When a device was changed while a stream was about to be destroyed, the <code>stream-reinit</code> task     may have been executed after the stream was destroyed, causing a use-after-free and a potentially     exploitable crash. (CVE-2020-6807)

  - When a JavaScript URL (javascript:) is evaluated and the result is a string, this string is parsed to     create an HTML document, which is then presented. Previously, this document's URL (as reported by the     document.location property, for example) was the originating javascript: URL which could lead to spoofing     attacks; it is now correctly the URL of the originating document. (CVE-2020-6808)

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	Severity
426478	Alpine: multiple librewolf packages: security update to 74.0-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	critical
426478	Alpine: multiple librewolf packages: security update to 74.0-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	critical
230282	Linux Distros Unpatched Vulnerability : CVE-2020-6813	Nessus	Misc.	medium
404364	Alpine: multiple firefox packages: security update to 74.0-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	critical
404364	Alpine: multiple firefox packages: security update to 74.0-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	critical
400454	Alpine: multiple firefox packages: security update to 73.0.1-r1 (deprecated)	Tenable Cloud Security	Alpine Linux Local Security Checks	critical
400454	Alpine: multiple firefox packages: security update to 73.0.1-r1 (deprecated)	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	critical
134442	Ubuntu 16.04 LTS / 18.04 LTS : Firefox vulnerabilities (USN-4299-1)	Nessus	Ubuntu Local Security Checks	critical
134405	Mozilla Firefox < 74.0	Nessus	Windows	critical
134404	Mozilla Firefox < 74.0	Nessus	MacOS X Local Security Checks	critical

Detections

Analytics

CVE-2020-6813

medium

Tenable Plugins

critical

critical

medium

critical

critical

critical

critical

critical

critical

critical