CVE-2025-30666 is a vulnerability identified in Zoom Communications, Inc's Zoom Workplace Apps for Windows. The issue is classified as a NULL pointer dereference (CWE-476), which occurs when the application attempts to access or dereference a pointer that is set to NULL, leading to a crash or denial of service (DoS). Specifically, this vulnerability allows an authenticated user to trigger a denial of service condition remotely via network access. The vulnerability does not require user interaction beyond authentication, and it can be exploited with low complexity due to the lack of additional access controls or complex conditions. The CVSS v3.1 base score is 6.5, indicating a medium severity level, with the vector AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. This means the attack can be launched remotely over the network with low attack complexity, requires low privileges (authenticated user), no user interaction, and impacts availability only, without affecting confidentiality or integrity. There are no known exploits in the wild at the time of publication, and no patches have been linked yet. The vulnerability affects unspecified versions of Zoom Workplace Apps for Windows, with references to affected versions available elsewhere. The root cause is a NULL pointer dereference, which typically results in application crashes, leading to denial of service conditions that could disrupt business communications and workflows relying on Zoom Workplace Apps.

For European organizations, this vulnerability poses a risk primarily to the availability of Zoom Workplace Apps on Windows systems. Given the widespread use of Zoom for remote work, collaboration, and communication across Europe, a denial of service attack could disrupt critical business operations, meetings, and workflows. Although the vulnerability requires authentication, insider threats or compromised user credentials could be leveraged to exploit this flaw. The impact is particularly significant for sectors heavily reliant on continuous communication platforms, such as finance, healthcare, government, and large enterprises. Disruptions could lead to operational delays, reduced productivity, and potential reputational damage. However, since confidentiality and integrity are not impacted, the risk of data breach or manipulation is not present with this vulnerability. The absence of known exploits reduces immediate risk but does not eliminate the potential for future exploitation once the vulnerability becomes publicly known.

To mitigate this vulnerability, European organizations should prioritize the following actions: 1) Monitor Zoom Communications' official channels for patches or updates addressing CVE-2025-30666 and apply them promptly once available. 2) Implement strict access controls and multi-factor authentication (MFA) to reduce the risk of unauthorized authenticated access that could be used to exploit this vulnerability. 3) Limit the number of users with access to Zoom Workplace Apps to only those necessary, minimizing the attack surface. 4) Employ network segmentation and monitoring to detect unusual activity or repeated application crashes that may indicate exploitation attempts. 5) Educate users about the importance of credential security to prevent insider threats or credential compromise. 6) Consider temporary mitigation strategies such as restricting access to Zoom Workplace Apps from untrusted networks or devices until a patch is applied. 7) Maintain robust incident response plans to quickly address any denial of service incidents affecting communication platforms.