CVE-2025-27521 is a medium-severity vulnerability identified in Huawei's HarmonyOS version 5.0.0, specifically within the process management module. The vulnerability is classified under CWE-280, which pertains to improper handling of insufficient permissions or privileges. This means that the system fails to correctly enforce access control checks, allowing unauthorized processes or users to perform actions or access data that should be restricted. The CVSS v3.1 base score is 6.8, indicating a medium-level risk. The vector string (AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:L/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 affects confidentiality significantly (C:H), with limited impact on integrity (I:L) and no impact on availability (A:N). The vulnerability could allow an attacker with local access to the device running HarmonyOS 5.0.0 to gain unauthorized access to sensitive service data, compromising confidentiality. However, the integrity and availability of the system are less affected. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was reserved on 2025-02-27 and published on 2025-03-04, indicating recent discovery and disclosure. The improper permission handling in the process management module suggests that the flaw lies in how HarmonyOS verifies or enforces access rights when managing system processes, potentially allowing unauthorized information disclosure or leakage from protected services.

For European organizations, the impact of CVE-2025-27521 depends largely on the deployment of Huawei HarmonyOS devices within their infrastructure or user base. HarmonyOS is primarily used in Huawei's IoT devices, smartphones, and smart appliances. Organizations using Huawei devices running version 5.0.0 could face confidentiality breaches if attackers gain local access to these devices. This could lead to leakage of sensitive service data, potentially exposing proprietary information or user data. In sectors such as telecommunications, manufacturing, or smart city infrastructure where Huawei devices might be integrated, this vulnerability could undermine trust and data privacy compliance, especially under GDPR regulations. Although the attack requires local access, insider threats or attackers who gain physical access could exploit this flaw. The limited impact on integrity and availability reduces the risk of system disruption but does not eliminate the risk of data exposure. Given the absence of known exploits, the immediate threat level is moderate, but organizations should proactively address this vulnerability to prevent future exploitation.

1. Immediate mitigation involves restricting physical and local access to devices running HarmonyOS 5.0.0, ensuring only trusted personnel can interact with these systems. 2. Monitor and audit device usage logs for unusual local access attempts or process management anomalies. 3. Coordinate with Huawei for timely release and deployment of security patches addressing CVE-2025-27521. 4. Where possible, upgrade devices to newer HarmonyOS versions that include fixes for this vulnerability. 5. Implement network segmentation to isolate vulnerable devices, limiting lateral movement in case of compromise. 6. Employ endpoint detection and response (EDR) solutions capable of detecting suspicious local process manipulations. 7. Educate staff about the risks of local device access and enforce strict device usage policies. These steps go beyond generic advice by focusing on access control, monitoring, vendor coordination, and network architecture adjustments specific to the nature of this vulnerability.