CVE-2025-49456 is a security vulnerability identified in the Zoom Clients for Windows, specifically related to a race condition in the installer process. This vulnerability is categorized under CWE-426, which refers to an Untrusted Search Path issue. The core problem arises when the installer executes in an environment where an unauthenticated local user can manipulate the search path used by the installer to load resources or executables. Due to the race condition, an attacker with local access can potentially influence the integrity of the Zoom application by causing it to load malicious code or files during installation or update processes. The vulnerability does not require any prior authentication or user interaction, making it easier for a local attacker to exploit. The CVSS v3.1 base score is 6.2, indicating a medium severity level. The vector details (AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N) show that the attack requires local access (AV:L), has low complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no confidentiality impact (C:N), high integrity impact (I:H), and no availability impact (A:N). No known exploits are currently reported in the wild, and no patches have been linked yet. This vulnerability could allow an attacker to compromise the integrity of the Zoom client installation, potentially leading to persistent malicious code execution or tampering with the application’s behavior.

For European organizations, this vulnerability poses a significant risk primarily in environments where Zoom Clients for Windows are installed and where multiple users have local access to the same machines, such as shared workstations, public terminals, or corporate laptops with multiple user profiles. An attacker exploiting this vulnerability could alter the Zoom client installation or update process, potentially inserting malicious code that could compromise the confidentiality and integrity of communications conducted via Zoom. While the vulnerability does not directly impact confidentiality or availability, the integrity compromise could lead to unauthorized code execution, data manipulation, or the introduction of backdoors. This is particularly concerning for sectors relying heavily on secure communications, such as finance, healthcare, government, and critical infrastructure within Europe. The lack of required authentication and user interaction lowers the barrier for exploitation, increasing the risk in environments with insufficient endpoint security controls. Additionally, given Zoom’s widespread use in Europe for remote work and collaboration, the potential attack surface is considerable. Organizations may face reputational damage, regulatory scrutiny under GDPR if personal data is indirectly compromised, and operational disruptions if the Zoom client is rendered untrustworthy.

To mitigate this vulnerability, European organizations should implement several targeted measures beyond generic patching advice. First, restrict local user permissions to prevent unauthorized users from accessing or modifying installation directories or executing installers. Employ application whitelisting and code integrity verification tools to detect and block unauthorized modifications to Zoom client files. Use endpoint detection and response (EDR) solutions to monitor for suspicious installer activity or unexpected file changes during Zoom client updates. Until an official patch is released, consider deploying Zoom clients with elevated security configurations, such as running installers with administrative privileges only accessible to trusted administrators. Network segmentation and endpoint isolation can limit the ability of an attacker to move laterally after local exploitation. Regularly audit and harden Windows search paths and environment variables to reduce the risk of untrusted path exploitation. Finally, educate users and IT staff about the risks of local privilege escalation and enforce strict control over software installation and update processes.