CVE-2024-10466 is a denial-of-service vulnerability classified under CWE-400 (Uncontrolled Resource Consumption) that impacts Mozilla Firefox and Thunderbird products. The flaw arises from the handling of DOM push subscription messages, where a specially crafted push message sent by a remote server can cause the parent process of the browser or email client to hang. This results in the application becoming unresponsive, effectively causing a denial-of-service condition. The vulnerability affects Firefox versions earlier than 132, Firefox ESR versions earlier than 128.4, and Thunderbird versions earlier than 128.4 and 132. The attack vector is network-based, requiring no privileges or user interaction, making it relatively easy to exploit remotely. The CVSS v3.1 base score is 7.5, reflecting high severity due to the impact on availability and ease of exploitation. Although no known exploits have been reported in the wild, the potential for disruption is significant, especially for organizations relying on these applications for communication and web access. The root cause is related to improper handling of push subscription messages, which can lead to resource exhaustion or deadlock in the parent process. This vulnerability does not affect confidentiality or integrity but can severely disrupt user operations by freezing the application.

For European organizations, the primary impact of CVE-2024-10466 is the disruption of critical communication and browsing activities due to application hangs. Organizations that depend on Firefox and Thunderbird for email and web access may experience productivity losses and operational delays. In sectors such as finance, government, and healthcare, where timely communication is essential, this denial-of-service could have cascading effects on service delivery and incident response. Additionally, the unavailability of these applications could force users to switch to less secure or unsupported alternatives, increasing overall risk. While the vulnerability does not lead to data breaches or integrity compromise, the availability impact alone can be costly, especially in environments with strict uptime requirements. The ease of remote exploitation without authentication increases the risk of targeted or opportunistic attacks, including potential use as part of larger multi-vector campaigns. Organizations with remote or hybrid workforces relying on these products are particularly vulnerable to disruption.

To mitigate CVE-2024-10466, European organizations should prioritize updating Mozilla Firefox and Thunderbird to versions 132 or later for Firefox and 128.4 or later for ESR and Thunderbird as soon as patches are released. Until patches are available, organizations can implement network-level controls to filter or block suspicious push subscription messages, particularly from untrusted or unknown sources. Monitoring network traffic for unusual push message patterns can help detect potential exploitation attempts. Administrators should also educate users about the risk of untrusted push notifications and encourage reporting of application hangs or crashes. Employing endpoint protection solutions that monitor application behavior may help detect and mitigate denial-of-service conditions. For critical environments, consider deploying alternative browsers or email clients temporarily if patching is delayed. Regularly reviewing and updating incident response plans to include denial-of-service scenarios related to client applications will improve preparedness. Finally, maintaining up-to-date asset inventories to identify affected versions is essential for targeted remediation.