CVE-2025-54639 is a medium-severity vulnerability identified in Huawei's HarmonyOS versions 5.0.1 and 5.1.0. The vulnerability is classified under CWE-502, which pertains to the deserialization of untrusted data. Specifically, this issue arises from a ParcelMismatch vulnerability during attribute deserialization. Deserialization vulnerabilities occur when untrusted or maliciously crafted data is processed by an application or system component, potentially leading to unexpected behavior or security breaches. In this case, the vulnerability affects the playback control screen functionality within HarmonyOS. Successful exploitation does not compromise confidentiality or integrity but can cause availability issues by triggering playback control screen display exceptions. The CVSS 3.1 base score is 5.5, reflecting a medium severity level, with an attack vector classified as local (AV:L), requiring low attack complexity (AC:L), and low privileges (PR:L). Notably, no user interaction is required (UI:N), and the scope is unchanged (S:U). The impact is limited to availability (A:H), with no impact on confidentiality or integrity. There are no known exploits in the wild, and no patches have been linked yet. The vulnerability was published on August 6, 2025, with the initial reservation date on July 28, 2025. The issue is technical in nature, involving improper handling of serialized data structures, which leads to mismatches during deserialization, causing the playback control screen to malfunction or crash. This could disrupt user experience and potentially affect applications relying on media playback controls within affected HarmonyOS devices.

For European organizations, the impact of CVE-2025-54639 is primarily related to availability disruptions in devices running affected versions of Huawei HarmonyOS. Organizations relying on HarmonyOS for mobile devices, IoT, or embedded systems that involve media playback could experience service interruptions or degraded user experience due to playback control screen exceptions. While the vulnerability does not directly expose sensitive data or allow unauthorized code execution, the denial or disruption of playback controls could affect business operations, especially in sectors like media, telecommunications, or any service relying on HarmonyOS-powered devices. Additionally, availability issues could lead to increased support costs and reduced productivity. The lack of known exploits reduces immediate risk, but the presence of this vulnerability in a widely deployed OS in certain European markets necessitates proactive mitigation to avoid potential future exploitation or cascading failures in integrated systems.

1. Immediate mitigation should focus on updating affected HarmonyOS devices to patched versions once Huawei releases official fixes. Monitoring Huawei's security advisories for patch availability is critical. 2. Until patches are available, organizations should restrict local access to devices running vulnerable versions, as the attack vector is local and requires low privileges. Limiting physical or local network access can reduce exploitation risk. 3. Implement application whitelisting and restrict installation of untrusted applications that might trigger deserialization with crafted data. 4. Employ runtime monitoring and anomaly detection on devices to identify abnormal playback control screen behavior or crashes, enabling rapid incident response. 5. For enterprise deployments, consider segmenting HarmonyOS devices from critical infrastructure to contain potential availability impacts. 6. Engage with Huawei support channels to obtain guidance and early access to patches or workarounds. 7. Educate users and administrators about the vulnerability and encourage reporting of playback control anomalies to IT security teams.