CVE-2025-46591 is a vulnerability identified in Huawei's HarmonyOS version 5.0.0, classified under CWE-602, which relates to client-side enforcement of server-side security. Specifically, this vulnerability involves an out-of-bounds data read in the authorization module of the operating system. An out-of-bounds read occurs when a program reads data outside the boundaries of allocated memory, which can lead to information disclosure or system instability. In this case, the vulnerability affects the confidentiality of services by potentially exposing sensitive authorization data that should be protected. The CVSS 3.1 base score is 6.2, indicating a medium severity level. The vector string (CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N) reveals that the attack requires local access (AV:L), has low attack complexity (AC:L), does not require privileges (PR:N) or user interaction (UI:N), and impacts confidentiality (C:H) without affecting integrity or availability. This suggests that an attacker with local access to the device can exploit this vulnerability to read sensitive authorization data, potentially bypassing security controls that are improperly enforced on the client side rather than the server side. No known exploits are currently in the wild, and no patches have been linked yet. The vulnerability highlights a design flaw where security enforcement is incorrectly delegated to the client, which can be manipulated to leak sensitive information.

For European organizations, the impact of CVE-2025-46591 primarily concerns confidentiality breaches on devices running HarmonyOS 5.0.0. Given HarmonyOS's increasing adoption in IoT devices, smartphones, and embedded systems, organizations using Huawei hardware or software in their infrastructure or supply chain could face risks of unauthorized data disclosure. This could lead to exposure of sensitive authorization tokens or credentials, potentially enabling further unauthorized access or lateral movement within networks. The local attack vector limits remote exploitation, but insider threats or compromised devices could leverage this vulnerability. Confidentiality breaches can undermine trust, violate data protection regulations such as GDPR, and result in financial and reputational damage. The absence of integrity and availability impacts reduces the risk of system disruption, but the confidentiality impact alone is significant for sectors handling sensitive data, including finance, healthcare, and critical infrastructure.

To mitigate CVE-2025-46591, European organizations should: 1) Inventory and identify all devices running HarmonyOS 5.0.0 within their environment, especially those with local access exposure. 2) Restrict physical and local access to these devices to trusted personnel only, minimizing the risk of local exploitation. 3) Monitor for unusual local activity or attempts to access authorization modules. 4) Engage with Huawei or authorized vendors to obtain and apply patches or updates as soon as they become available. 5) Implement network segmentation to isolate vulnerable devices from critical systems. 6) Employ endpoint detection and response (EDR) solutions capable of detecting anomalous memory access patterns indicative of out-of-bounds reads. 7) Review and harden authorization mechanisms to ensure server-side enforcement is robust and not reliant on client-side controls. 8) Educate staff about the risks of local device compromise and enforce strict device usage policies. These steps go beyond generic advice by focusing on local access control, monitoring, and architectural review of authorization enforcement.