Full Report
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 Focus for iOS is a private mobile browser that automatically blocks online trackers and most ads.Mozilla Thunderbird is an email client.Mozilla Thunderbird ESR is a version of the email client intended to be deployed in large organizations.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.
Analysis Summary
Given the scope of the information provided, this summary aggregates the known vulnerabilities under the MS-ISAC Advisory context, focusing on the most severe findings regarding arbitrary code execution. Specific CVE severity scores and precise patch versions are not listed individually for all flaws but are summarized based on the advisory's intent.
# Vulnerability: Multiple Critical Flaws in Mozilla Products Leading to Arbitrary Code Execution
## CVE Details
- CVE ID: Multiple, including **CVE-2025-10527**, **CVE-2025-10528**, **CVE-2025-10537** (Memory safety bugs with potential for arbitrary code execution).
- CVSS Score: Not explicitly provided for the advisory as a whole, but the highest impact is **Arbitrary Code Execution**.
- CWE: Varies (Use-After-Free, Undefined Behavior, Memory Corruption).
## Affected Systems
- Products:
- Mozilla Firefox
- Mozilla Firefox ESR
- Mozilla Focus for iOS
- Mozilla Thunderbird
- Mozilla Thunderbird ESR
- Versions:
- Thunderbird versions **prior to 140.3** and **prior to 143**
- Focus for iOS versions **prior to 143.0**
- Firefox ESR versions **prior to 140.3** and **prior to 115.28**
- Firefox versions **prior to 143**
- Configurations: Standard installations of the listed products running vulnerable versions.
## Vulnerability Description
Multiple vulnerabilities exist across several Mozilla products. The most severe flaws relate to memory corruption within the **Graphics** component, including a **use-after-free** condition (CVE-2025-10527) and an **undefined behavior/invalid pointer** issue (CVE-2025-10528). Additionally, certain **memory safety bugs** (CVE-2025-10537) showed evidence of corruption that Mozilla presumes could lead to arbitrary code execution. These severe vulnerabilities fall under the MITRE ATT&CK tactic **Initial Access** via **Drive-by Compromise (T1189)**. Lower severity issues involve SOP bypass, integer overflow, and information disclosure in various components.
## Exploitation
- Status: **Not exploited in the wild**.
- Complexity: Assumed **Medium to High** for the RCE-capable bugs, especially those requiring sandbox escape, though PoC status is unstated.
- Attack Vector: Primarily **Network** (via malicious web content triggering browser flaws).
## Impact
- Confidentiality: **High** (If exploited, attackers can view/change data).
- Integrity: **High** (If exploited, attackers can install programs or change data).
- Availability: **Moderate to High** (Loss of integrity or system stability).
*Note: Impact severity is dependent on the user's system privileges; administrative users face the highest risk.*
## Remediation
### Patches
Specific patches are referenced via vendor advisories (e.g., MFSA 2025-73 through 2025-78), which apply fixes to the following minimum versions:
- Firefox: **143 or later**
- Firefox ESR: **140.3 or 115.28 or later**
- Thunderbird: **140.3 or 143 or later**
- Focus for iOS: **143.0 or later**
### Workarounds
No specific workarounds were detailed in the provided summary text, only the general recommendation to update immediately.
## Detection
- Indicators of Compromise: Not explicitly listed, but successful exploitation would manifest as unexpected program installation, unauthorized data modification, or crash reports related to the Graphics or Memory components.
- Detection methods and tools: Implement robust vulnerability management processes, including automated application patch management and remediation based on risk (Safeguards 7.4 and 7.7).
## References
- Vendor Advisories: Multiple Mozilla Security Advisories (MSFA) issued concurrently (e.g., referencing MFSA 2025-73 through MFSA 2025-78).
- Relevant links:
- hxxps://www.mozilla.org/en-US/security/advisories/
- hxxps://www.mozilla.org/en-US/security/advisories/mfsa2025-73/
- hxxps://www.mozilla.org/en-US/security/advisories/mfsa2025-74/
- hxxps://www.mozilla.org/en-US/security/advisories/mfsa2025-75/
- hxxps://www.mozilla.org/en-US/security/advisories/mfsa2025-76/
- hxxps://www.mozilla.org/en-US/security/advisories/mfsa2025-77/
- hxxps://www.mozilla.org/en-US/security/advisories/mfsa2025-78/