MULTIPLE VULNERABILITIES IN MOZILLA PRODUCTS IDENTIFIED

A cybersecurity advisory was issued yesterday, Dec. 16, 2020, regarding multiple vulnerabilities in Mozilla products. The vulnerabilities could allow an attacker to execute arbitrary code, which could potentially lead to a breach.

What It Is:

Multiple vulnerabilities have been discovered in Mozilla Firefox, Firefox Extended Support Release (ESR) and Mozilla Thunderbird, the most severe of which could allow for arbitrary code execution. Mozilla Firefox is a web browser used to access the Internet. Mozilla Firefox ESR is a version of the web browser intended to be deployed in large organizations. Mozilla Thunderbird is an email client.

Successful exploitation of these vulnerabilities could allow for arbitrary code execution. Depending on the privileges associated with the user an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

Read the original Mozilla Foundation Security Advisories below for more information:

• Security Vulnerabilities fixed in Firefox 84
• Security Vulnerabilities fixed in Firefox ESR 78.6
• Security Vulnerabilities fixed in Thunderbird 78.6

Threat Intelligence:

There are currently no reports of these vulnerabilities being exploited in the wild.

Systems Affected:

• Mozilla Firefox versions prior to 84
• Mozilla Firefox ESR versions prior to 78.6
• Mozilla Thunderbird versions prior to 78.6

Risk:

Government:

• Large and medium government entities: High
• Small government entities: Medium

Businesses:

• Large and medium business entities: High
• Small business entities: Medium

Home users: Low

What It Means:

If you and/or your business utilize the Mozilla products mentioned above, you will need to apply the appropriate updates provided by Mozilla to vulnerable systems, immediately following proper testing.

Technical Summary:

Multiple vulnerabilities have been discovered in Mozilla Firefox, Firefox Extended Support Release (ESR) and Mozilla Thunderbird, the most severe of which could allow for arbitrary code execution. Details of these vulnerabilities are as follows:

• A heap based buffer-overflow vulnerability. Specifically, this issue occurs due to a boundary error within WebGL component. [CVE-2020-26971]
• A security-bypass vulnerability. Specifically, this issue occurs due to insufficient validation of user-supplied input within CSS Sanitizer. [CVE-2020-26973]
• A denial-of-service vulnerability. Specifically, this issue occurs due to incorrect casting of the 'StyleGenericFlexBasis' object. [CVE-2020-26974]
• A security vulnerability. Specifically, this issue exists due to application does not properly impose security restrictions. A remote attacker can create a specially crafted webpage and send probes to hosts in internal network as well as to services on the user's local machine. [CVE-2020-26978]
• An information-disclosure vulnerability. Specifically, this issue exists due to the proxy.onRequest API does not use proxy when viewing source code of the web application. [CVE-2020-35111]
• A security vulnerability. Specifically, this issue exists due to the way Firefox processes downloaded files without extensions on Windows operating system. [CVE-2020-35112]
• A security vulnerability that occurs due to memory safety bugs. [CVE-2020-35113]

What To Do:

We recommend the following actions be taken:

• Apply appropriate updates provided by Mozilla to vulnerable systems, immediately after appropriate testing.
• Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack.
• Remind users not to visit websites or follow links provided by unknown or untrusted sources.
• Inform and educate users regarding the threats posed by hypertext links contained in emails or attachments especially from untrusted sources.
• Apply the Principle of Least Privilege to all systems and services.

Negative Consequences of Lost or Stolen Data:

The loss or theft of proprietary data can have severe impacts, particularly if the compromise becomes public and sensitive information is exposed. Possible impacts include:

• Temporary or permanent loss of sensitive or proprietary information.
• Disruption to regular operations.
• Financial losses incurred to restore systems and files.
• Potential harm to an organization’s reputation.

Should your agency or business need assistance with issues arising from vulnerabilities in Mozilla products including updates and/or patches, Dox can help. Please contact Dox if there is anything we can do to assist in securing your agency, business, or organization.

Thank you for your time and stay safe online.