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Mozilla Products Could Allow for Arbitrary Code Execution – PATCH: NOW – TLP: CLEAR

TLP:CLEAR
MS-ISAC CYBERSECURITY ADVISORY

MS-ISAC ADVISORY NUMBER:
2024-056

DATE(S) ISSUED:
05/14/2024

SUBJECT:
Multiple Vulnerabilities in Mozilla Products Could Allow for Arbitrary Code Execution

OVERVIEW:
Multiple vulnerabilities have been discovered in Mozilla Products, 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 the most severe of these vulnerabilities could allow for arbitrary 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 no reports that these vulnerabilities are being exploited in the wild

SYSTEMS AFFECTED:

  • Firefox ESR versions prior to 115.11
  • Thunderbird versions prior to 115.11
  • Firefox versions prior to 126

 

RISK:
Government:

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

 

Businesses:

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

Home users: Low

TECHNICAL SUMMARY:
Multiple vulnerabilities have been discovered in Mozilla Products, the most severe of which could allow for arbitrary code execution. Details of the most critical vulnerabilities are as follows:

Tactic: Initial Access (TA0001):

Technique: Drive-by Compromise (T1189):

  • Multiple WebRTC threads could have claimed a newly connected audio input leading to use-after-free. (CVE-2024-4764)
  • A type check was missing when handling fonts in PDF.js, which would allow arbitrary JavaScript execution in the PDF.js context. (CVE-2024-4367)
  • Web application manifests were stored by using an insecure MD5 hash which allowed for a hash collision to overwrite another application’s manifest. This could have been exploited to run arbitrary code in another application’s context. This issue only affects Firefox for Android. Other versions of Firefox are unaffected. (CVE-2024-4765)
  • Different techniques existed to obscure the fullscreen notification in Firefox for Android. These could have lead to potential user confusion and spoofing attacks. This bug only affects Firefox for Android. Other versions of Firefox are unaffected. (CVE-2024-4766)
  • If the browser.privatebrowsing.autostart preference is enabled, IndexedDB files were not properly deleted when the window was closed. This preference is disabled by default in Firefox and Thunderbird. (CVE-2024-4767)
  • A bug in popup notifications’ interaction with WebAuthn made it easier for an attacker to trick a user into granting permissions. (CVE-2024-4768)
  • When importing resources using Web Workers, error messages would distinguish the difference between application/javascript responses and non-script responses. This could have been abused to learn information cross-origin. (CVE-2024-4769)
  • When saving a page to PDF, certain font styles could have led to a potential use-after-free crash. (CVE-2024-4770)
  • A memory allocation check was missing which would lead to a use-after-free if the allocation failed. This could have triggered a crash or potentially be leveraged to achieve code execution. (CVE-2024-4771)
  • Memory safety bugs present in Firefox 125, Firefox ESR 115.10, and Thunderbird 115.10. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. (CVE-2024-4777)

Additional lower severity vulnerabilities include:

  • An HTTP digest authentication nonce value was generated using rand() which could lead to predictable values. (CVE-2024-4772)
  • When a network error occurred during page load, the prior content could have remained in view with a blank URL bar. This could have been used to obfuscate a spoofed web site. (CVE-2024-4773)
  • The ShmemCharMapHashEntry() code was susceptible to potentially undefined behavior by bypassing the move semantics for one of its data members. (CVE-2024-4774)
  • An iterator stop condition was missing when handling WASM code in the built-in profiler, potentially leading to invalid memory access and undefined behavior. Note: This issue only affects the application when the profiler is running. (CVE-2024-4775)
  • A file dialog shown while in full-screen mode could have resulted in the window remaining disabled. (CVE-2024-4776)
  • Memory safety bugs present in Firefox 125. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. (CVE-2024-4778)

Successful exploitation of the most severe of these vulnerabilities could allow for arbitrary 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 the stable channel update provided by Mozilla to vulnerable systems immediately after appropriate testing. (M1051: Update Software)
    • Safeguard 7.1 : Establish and Maintain a Vulnerability Management Process: Establish and maintain a documented vulnerability management process for enterprise assets. Review and update documentation annually, or when significant enterprise changes occur that could impact this Safeguard.
    • Safeguard 7.4: Perform Automated Application Patch Management: Perform application updates on enterprise assets through automated patch management on a monthly, or more frequent, basis.
    • Safeguard 7.5 : Perform Automated Vulnerability Scans of Internal Enterprise Assets: Perform automated vulnerability scans of internal enterprise assets on a quarterly, or more frequent, basis. Conduct both authenticated and unauthenticated scans, using a SCAP-compliant vulnerability scanning tool.
  • Apply the Principle of Least Privilege to all systems and services. Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack. (M1026: Privileged Account Management)
    • Safeguard 4.7: Manage Default Accounts on Enterprise Assets and Software: Manage default accounts on enterprise assets and software, such as root, administrator, and other pre-configured vendor accounts. Example implementations can include: disabling default accounts or making them unusable.
    • Safeguard 5.4: Restrict Administrator Privileges to Dedicated Administrator Accounts: Restrict administrator privileges to dedicated administrator accounts on enterprise assets. Conduct general computing activities, such as internet browsing, email, and productivity suite use, from the user’s primary, non-privileged account.
  • Use capabilities to detect and block conditions that may lead to or be indicative of a software exploit occurring. (M1050: Exploit Protection)
    • Safeguard 10.5:  Enable Anti-Exploitation Features: Enable anti-exploitation features on enterprise assets and software, where possible, such as Microsoft® Data Execution Prevention (DEP), Windows® Defender Exploit Guard (WDEG), or Apple® System Integrity Protection (SIP) and Gatekeeper™.
  • Restrict use of certain websites, block downloads/attachments, block JavaScript, restrict browser extensions, etc. (M1021: Restrict Web-Based Content)
    • Safeguard 9.2: Use DNS Filtering Services: Use DNS filtering services on all enterprise assets to block access to known malicious domains.
    • Safeguard 9.3: Maintain and Enforce Network-Based URL Filters: Enforce and update network-based URL filters to limit an enterprise asset from connecting to potentially malicious or unapproved websites. Example implementations include category-based filtering, reputation-based filtering, or through the use of block lists. Enforce filters for all enterprise assets.
    • Safeguard 9.6: Block Unnecessary File Types: Block unnecessary file types attempting to enter the enterprise’s email gateway.
  • Block execution of code on a system through application control, and/or script blocking. (M1038: Execution Prevention)
    1. Safeguard 2.5 : Allowlist Authorized Software: Use technical controls, such as application allowlisting, to ensure that only authorized software can execute or be accessed. Reassess bi-annually, or more frequently.
    2. Safeguard 2.6 : Allowlist Authorized Libraries: Use technical controls to ensure that only authorized software libraries, such as specific .dll, .ocx, .so, etc., files, are allowed to load into a system process. Block unauthorized libraries from loading into a system process. Reassess bi-annually, or more frequently.
    3. Safeguard 2.7 : Allowlist Authorized Scripts: Use technical controls, such as digital signatures and version control, to ensure that only authorized scripts, such as specific .ps1, .py, etc., files, are allowed to execute. Block unauthorized scripts from executing. Reassess bi-annually, or more frequently.
  • Use capabilities to prevent suspicious behavior patterns from occurring on endpoint systems. This could include suspicious process, file, API call, etc. behavior. (M1040: Behavior Prevention on Endpoint)
    1. Safeguard 13.2 : Deploy a Host-Based Intrusion Detection Solution: Deploy a host-based intrusion detection solution on enterprise assets, where appropriate and/or supported.
    2. Safeguard 13.7 : Deploy a Host-Based Intrusion Prevention Solution: Deploy a host-based intrusion prevention solution on enterprise assets, where appropriate and/or supported. Example implementations include use of an Endpoint Detection and Response (EDR) client or host-based IPS agent.
  • Inform and educate users regarding the threats posed by hypertext links contained in emails or attachments especially from un-trusted sources. Remind users not to visit un-trusted websites or follow links provided by unknown or un-trusted sources. (M1017: User Training)
    1. Safeguard 14.1: Establish and Maintain a Security Awareness Program: Establish and maintain a security awareness program. The purpose of a security awareness program is to educate the enterprise’s workforce on how to interact with enterprise assets and data in a secure manner. Conduct training at hire and, at a minimum, annually. Review and update content annually, or when significant enterprise changes occur that could impact this Safeguard.
    2. Safeguard 14.2: Train Workforce Members to Recognize Social Engineering Attacks: Train workforce members to recognize social engineering attacks, such as phishing, pre-texting, and tailgating.

REFERENCES:

Mozilla: 
https://www.mozilla.org/en-US/security/advisories/ 
https://www.mozilla.org/en-US/security/advisories/mfsa2024-21/ 
https://www.mozilla.org/en-US/security/advisories/mfsa2024-22/ 
https://www.mozilla.org/en-US/security/advisories/mfsa2024-23/ 

CVE:                                  
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4367
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4764
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4765
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4766
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4767
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4768
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4769
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4770
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4771
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4772
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4773
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4774
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4775
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4776
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4777
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4778
 

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