CVE-2024-9396 in Thunderbird
Summary
by MITRE • 10/01/2024
It is currently unknown if this issue is exploitable but a condition may arise where the structured clone of certain objects could lead to memory corruption. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3, and Thunderbird < 131.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 03/09/2025
This vulnerability resides within the Firefox browser and Thunderbird email client ecosystems, specifically targeting the structured clone algorithm implementation that handles object serialization and deserialization. The issue manifests when certain objects undergo the structured clone process, potentially leading to memory corruption conditions that could be exploited by malicious actors. The vulnerability affects multiple Mozilla products including Firefox versions prior to 131, Firefox ESR versions prior to 128.3, and Thunderbird versions prior to 128.3 and 131 respectively, indicating a widespread impact across the Mozilla ecosystem. The structured clone algorithm is a core component used for transferring objects between different execution contexts, particularly in web workers and cross-origin communication scenarios, making it a critical security surface area.
The technical flaw involves memory corruption that occurs during the structured clone operation of specific object types, potentially allowing attackers to manipulate memory layout and execute arbitrary code. This type of vulnerability typically stems from inadequate bounds checking or improper memory management within the serialization process, where the system fails to properly validate or handle certain object characteristics during cloning operations. The vulnerability's exploitable nature remains uncertain, but the potential for memory corruption suggests that attackers could leverage this to achieve privilege escalation or remote code execution depending on the attack surface and execution context. The condition that triggers this vulnerability appears to be related to specific object properties or types that when cloned, cause the underlying memory management system to behave unpredictably, creating potential for heap corruption or other memory-related exploits.
The operational impact of this vulnerability extends beyond simple browser or email client compromise, as it affects core functionality that enables web applications and email processing to operate securely. Memory corruption vulnerabilities of this nature can lead to application crashes, data loss, or more severe consequences including complete system compromise when exploited successfully. The affected products represent critical infrastructure components used by millions of users globally, meaning that exploitation could result in widespread security incidents. The vulnerability affects both regular Firefox releases and the extended support releases, indicating that organizations maintaining older versions of these applications remain at risk, particularly those with limited update capabilities or compliance requirements that prevent immediate patching.
Security mitigations for this vulnerability should prioritize immediate patching of affected versions to the latest stable releases, as this represents the most effective defense against exploitation. Organizations should implement monitoring for unusual application behavior or crashes that might indicate exploitation attempts, particularly in environments where these applications are heavily used. Network segmentation and application whitelisting can provide additional layers of protection, though these measures are less effective against sophisticated attacks that can bypass such controls. The vulnerability aligns with common weakness enumerations such as CWE-121 for heap-based buffer overflow conditions and may relate to ATT&CK techniques involving privilege escalation and code execution through memory corruption vulnerabilities. System administrators should also consider implementing security updates through managed deployment processes and regularly review their patch management procedures to ensure timely resolution of such critical vulnerabilities.