CVE-2023-5174 : Exploit Details and Defense Strategies

This CVE-2023-5174 was published by Mozilla on September 27, 2023. The vulnerability affects Firefox, Firefox ESR, and Thunderbird, specifically on Windows operating systems in non-standard configurations. The issue involves a use-after-free vulnerability that could lead to a potentially exploitable crash.

Understanding CVE-2023-5174

This section will delve into the details of CVE-2023-5174, including the vulnerability description, impact, affected systems, and exploitation mechanism.

What is CVE-2023-5174?

The CVE-2023-5174 vulnerability arises from a scenario where Windows fails to duplicate a handle during process creation. This failure may cause the sandbox code to inadvertently free a pointer twice, resulting in a use-after-free situation and a potentially exploitable crash. Notably, this bug only impacts Firefox on Windows under non-standard configurations, such as utilizing 'runas'. Other operating systems are not affected by this vulnerability.

The Impact of CVE-2023-5174

The impact of CVE-2023-5174 is significant as it exposes affected systems to potential crashes and exploitability. Users of Firefox versions below 118, Firefox ESR versions below 115.3, and Thunderbird versions below 115.3 are at risk.

Technical Details of CVE-2023-5174

In this section, we will explore the specific technical aspects of CVE-2023-5174, including the vulnerability description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability involves a double-free in process spawning on Windows, triggered by a failure to duplicate a handle during process creation.

Affected Systems and Versions

Firefox < 118
Firefox ESR < 115.3
Thunderbird < 115.3

Exploitation Mechanism

The exploitation of this vulnerability occurs when the sandbox code unintentionally frees a pointer twice due to Windows' failure to duplicate a handle during process creation.

Mitigation and Prevention

To safeguard systems from CVE-2023-5174, certain immediate steps and long-term security practices should be employed.

Immediate Steps to Take

Update affected applications (Firefox, Firefox ESR, Thunderbird) to versions that contain patches addressing CVE-2023-5174.
Avoid running the applications in non-standard configurations on Windows.

Long-Term Security Practices

Regularly update software to the latest versions to ensure all security patches are applied promptly.
Employ secure configurations and practices while using applications to minimize the risk of exploiting vulnerabilities.

Patching and Updates

Refer to the Mozilla Security Advisories MFSAs (MFSAs 2023-41, 42, 43) for detailed information on the patches and updates released to mitigate CVE-2023-5174.