Multiple vulnerabilities have been discovered in Mozilla Firefox, Firefox Extended Support Release (ESR), Firefox for Android, Focus, and 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.

‍March 8th – UPDATED OVERVIEW:
     •    Mozilla Thunderbird is an email client.
     •    Mozilla Firefox is a dedicated private browser with automatic protection and ad blocking.
     •    Mozilla Firefox for Android is the Android based Firefox Browser on Android devices.

Successful exploitation of the most severe 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.​

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SYSTEMS AFFECTED:

     •    Mozilla Firefox versions prior to 98
      •    Firefox ESR versions prior to 91.7

March 8th – UPDATED SYSTEMS AFFECTED:
     •    Firefox for Android versions prior to 97.3.0
     •    Firefox Focus versions prior to 97.3.0
     •    Mozilla Thunderbird versions prior to 91.6.2
 

RISK:
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Government:

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

Businesses:

• Large and medium business entities: High
• Small business entities: Medium
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Home users: Low

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TECHNICAL SUMMARY:

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

•Use-after-free in XSLT parameter processing (CVE-2022-26485)

•Use-after-free in WebGPU IPC framework(CVE-2022-26486)

‍March 8th – UPDATED TECHNICAL SUMMARY:
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     •    Browser window spoof using full screen mode (CVE-2022-26383)
     •    iFrame allow-scripts sandbox bypass (CVE-2022-26384)
     •    Time-of-check time-of-use bug when verifying add-on signatures (CVE-2022-26387)
     •    Use-after-free in text reflows (CVE-2022-26381)
     •    Temporary files downloaded to /tmp and accessible by other local users (CVE-2022-36386)
     •    Autofill text could be exfiltrated via side-channel attacks(CVE-2022-26382)
     •    Use-after-free in thread shutdown (CVE-2022-26385)
     •    Memory safety bugs fixed in Firefox 98 (CVE-2022-0843)

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RECOMMENDATIONS:
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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 un-trusted websites or follow links provided by unknown or un-trusted sources.
       •    Inform and educate users regarding the threats posed by hypertext links contained in emails or attachments especially from un-trusted sources.
      •    Apply the Principle of Least Privilege to all systems and services.

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REFERENCES:

Mozilla:
https://www.mozilla.org/en-US/security/advisories/mfsa2022-09/

March 8th – UPDATED REFERENCES:
https://www.mozilla.org/en-US/security/advisories/mfsa2022-10/ 
https://www.mozilla.org/en-US/security/advisories/mfsa2022-11/ 

CVE (Other CVE links have not yet been published for the Firefox Advisory released on 03/08 – Please refer to the Mozilla “mfsa2022-11” link above):
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-26485
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-26486

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