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Multiple Vulnerabilities in Mozilla Firefox Could Allow for Remote Code Execution

MS-ISAC ADVISORY NUMBER:

2020-075

DATE(S) ISSUED:

06/03/2020

OVERVIEW:

Multiple vulnerabilities have been discovered in Mozilla Firefox, the most severe of which could allow for remote code execution. Mozilla Firefox is a web browser used to access the Internet. Successful exploitation of the most severe of these vulnerabilities could allow for remote code execution in the context of the logged-on user. 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.

THREAT INTELLIGENCE:

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

SYSTEMS AFFECTED:

  • Mozilla Firefox versions prior to 77.0

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

TECHNICAL SUMMARY:

Multiple vulnerabilities have been discovered in Mozilla Firefox, the most severe of which could allow for remote code execution. These vulnerabilities can be exploited if a user visits a specially crafted web page. Details of these vulnerabilities are as follows:

  • One timing vulnerability exists when performing DSA signatures that could lead to leaking private keys. (CVE-2020-12399)
  • One use-after-free vulnerability exists in the SharedWorkerService that causes a potentially exploitable crash. (CVE-2020-12405)
  • One type confusion vulnerability exists that allows arbitrary code execution due to an error during removal of unboxed JavaScript objects. (CVE-2020-12406)
  • One memory leak vulnerability exists in WebRender that allows for a local user to view the contents of memory. (CVE-2020-12407)
  • Two spoofing vulnerabilities exist to trick users into navigating to malicious webpages that look legitimate. (CVE-2020-12408, CVE-2020-12409)
  • Two buffer overflow vulnerabilities exist that allows for arbitrary code execution due to errors wen processing HTML content. (CVE-2020-12410, CVE-2020-12411)

Successful exploitation of the most severe of these vulnerabilities could allow for remote code execution in the context of the logged-on user. 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.

RECOMMENDATIONS:

We recommend the following actions be taken:

  • Apply appropriate patches 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 un-trusted websites or follow links provided by unknown or un-trusted sources.
  • Apply the Principle of Least Privilege to all systems and services

REFERENCES:

Information Hub : Advisories


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