CVE-2025-66323 is a vulnerability identified in Huawei's HarmonyOS, specifically within the card module, due to an improperly implemented security check, categorized under CWE-358 (Improperly Implemented Security Check for Standard). This flaw allows an attacker with local access and requiring user interaction to exploit the vulnerability, potentially causing an impact on system availability. The affected versions include HarmonyOS 5.0.1, 5.1.0, and 6.0.0. The CVSS v3.1 score is 5.3, indicating medium severity, with vector metrics AV:L (Local), AC:L (Low complexity), PR:N (No privileges required), UI:R (Requires user interaction), and impacts on confidentiality, integrity, and availability rated as low to medium. The vulnerability does not currently have known exploits in the wild, and no patches have been published yet. The improper security check could allow malicious local users or applications to disrupt system services or cause denial-of-service conditions by exploiting the card module's flawed validation logic. Since the attack requires local access and user interaction, remote exploitation is not feasible, limiting the attack surface primarily to users or malware already present on the device. The vulnerability's impact on availability could affect device stability or functionality, potentially disrupting business operations relying on HarmonyOS devices.

For European organizations, the primary impact of CVE-2025-66323 lies in potential availability disruptions on devices running affected versions of HarmonyOS. This could translate into denial-of-service conditions or degraded device performance, impacting user productivity and operational continuity. Confidentiality and integrity impacts are assessed as low, reducing risks of data breaches or unauthorized data modification. However, organizations relying on HarmonyOS for critical communications or operations may experience interruptions. The requirement for local access and user interaction limits the threat to scenarios involving insider threats, compromised endpoints, or social engineering attacks. The absence of known exploits reduces immediate risk but underscores the need for proactive mitigation. Given Huawei's significant market presence in certain European countries, especially in telecommunications and consumer devices, the vulnerability could affect sectors such as government, telecommunications, and enterprises using Huawei hardware or software. The medium severity rating suggests moderate urgency in addressing the vulnerability to prevent potential service disruptions.

1. Monitor Huawei's official security advisories and apply patches promptly once released to address CVE-2025-66323. 2. Restrict local access to HarmonyOS devices by enforcing strong physical security controls and limiting user privileges to reduce the risk of exploitation. 3. Educate users about the risks of social engineering and the importance of not interacting with untrusted prompts or applications that could trigger the vulnerability. 4. Implement endpoint protection solutions capable of detecting suspicious local activities or attempts to exploit system modules. 5. Conduct regular security audits and vulnerability assessments on devices running HarmonyOS to identify and remediate potential weaknesses. 6. For organizations deploying HarmonyOS in critical environments, consider network segmentation and device isolation to contain potential impacts. 7. Maintain up-to-date backups and incident response plans to quickly recover from availability disruptions. 8. Collaborate with Huawei support channels for guidance and early access to patches or mitigations if available.