Highlight.js is a syntax highlighter written in JavaScript. Highlight.js versions before 9.18.2 and 10.1.2 are vulnerable to Prototype Pollution. A malicious HTML code block can be crafted that will result in prototype pollution of the base object's prototype during highlighting. If you allow users to insert custom HTML code blocks into your page/app via parsing Markdown code blocks (or similar) and do not filter the language names the user can provide you may be vulnerable. The pollution should just be harmless data but this can cause problems for applications not expecting these properties to exist and can result in strange behavior or application crashes, i.e. a potential DOS vector. If your website or application does not render user provided data it should be unaffected. Versions 9.18.2 and 10.1.2 and newer include fixes for this vulnerability. If you are using version 7 or 8 you are encouraged to upgrade to a newer release.

The remote Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS host has packages installed that are affected by a vulnerability as referenced in the USN-8276-1 advisory.

    It was discovered that Highlight.js used plain JavaScript objects for internal language name lookups,     making them susceptible to prototype pollution attacks. An attacker could use this to cause a denial of     service or unexpected application behaviour.

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

  - Highlight.js is a syntax highlighter written in JavaScript. Highlight.js versions before 9.18.2 and 10.1.2     are vulnerable to Prototype Pollution. A malicious HTML code block can be crafted that will result in     prototype pollution of the base object's prototype during highlighting. If you allow users to insert     custom HTML code blocks into your page/app via parsing Markdown code blocks (or similar) and do not filter     the language names the user can provide you may be vulnerable. The pollution should just be harmless data     but this can cause problems for applications not expecting these properties to exist and can result in     strange behavior or application crashes, i.e. a potential DOS vector. If your website or application does     not render user provided data it should be unaffected. Versions 9.18.2 and 10.1.2 and newer include fixes     for this vulnerability. If you are using version 7 or 8 you are encouraged to upgrade to a newer release.
    (CVE-2020-26237)

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

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - Highlight.js is a syntax highlighter written in JavaScript. Highlight.js versions before 9.18.2 and 10.1.2
    are vulnerable to Prototype Pollution. A malicious HTML code block can be crafted that will result in
    prototype pollution of the base object's prototype during highlighting. If you allow users to insert
    custom HTML code blocks into your page/app via parsing Markdown code blocks (or similar) and do not filter
    the language names the user can provide you may be vulnerable. The pollution should just be harmless data
    but this can cause problems for applications not expecting these properties to exist and can result in
    strange behavior or application crashes, i.e. a potential DOS vector. If your website or application does
    not render user provided data it should be unaffected. Versions 9.18.2 and 10.1.2 and newer include fixes
    for this vulnerability. If you are using version 7 or 8 you are encouraged to upgrade to a newer release.
    (CVE-2020-26237)

The version of MySQL Enterprise Monitor installed on the remote host are affected by multiple vulnerabilities as referenced in the July 2022 CPU advisory.   
  - Vulnerability in the MySQL Enterprise Monitor product of Oracle MySQL (component: Monitoring: General     (highlight.js)). Supported versions that are affected are 8.0.30 and prior. A malicious HTML code block can be     crafted that will result in prototype pollution of the base object's prototype during highlighting.     The pollution should just be harmless data but this can cause problems for applications not expecting these     properties to exist and can result in strange behavior or application crashes, i.e. a potential DOS vector.     (CVE-2020-26237)   
  - Vulnerability in the MySQL Enterprise Monitor product of Oracle MySQL (component: Monitoring: General     (Apache Struts)). Supported versions that are affected are 8.0.30 and prior. some tag attributes could perform a     double evaluation if a developer applied forced OGNL evaluation by using the %{...} syntax. Using forced OGNL     evaluation on untrusted user input can lead to a Remote Code Execution and security degradation. (CVE-2021-31805)

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

An issue has been found in highlight.js, a JavaScript library for syntax highlighting. If a website or application renders user provided data it might be affected by a Prototype Pollution. This might result in strange behavior or crashes of applications that do not correctly handle unknown properties.

For Debian 9 stretch, this problem has been fixed in version 8.2+ds-5+deb9u1.

We recommend that you upgrade your highlight.js packages.

For the detailed security status of highlight.js please refer to its security tracker page at:
https://security-tracker.debian.org/tracker/highlight.js

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
315737	Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS : Highlight.js vulnerability (USN-8276-1)	Nessus	Ubuntu Local Security Checks	high
250926	Linux Distros Unpatched Vulnerability : CVE-2020-26237	Nessus	Misc.	high
419305	SCA: security update for highlight.js (GHSA-vfrc-7r7c-w9mx)	Tenable Cloud Security	SCA Checks	high
419305	SCA: security update for highlight.js (GHSA-vfrc-7r7c-w9mx)	Tenable Self-Hosted Container Security	SCA Checks	high
163292	Oracle MySQL Enterprise Monitor (July 2022 CPU)	Nessus	CGI abuses	critical
144666	Debian DLA-2511-1 : highlight.js security update	Nessus	Debian Local Security Checks	high

Detections

Analytics

CVE-2020-26237

high

Tenable Plugins

high

high

high

high

critical

high