CVE-2025-53177 is a permission bypass vulnerability identified in the calendar storage module of Huawei's HarmonyOS, specifically affecting versions 4.0.0, 4.2.0, and 4.3.0. The vulnerability is categorized under CWE-264, which pertains to improper permissions, privileges, and access controls. This flaw allows an attacker with limited privileges (PR:L) and requiring user interaction (UI:R) to bypass intended permission checks within the calendar storage component. The exploitation vector is local (AV:L), meaning the attacker must have local access to the device, such as through a compromised user account or physical access. The vulnerability does not impact confidentiality but can affect the integrity and availability of the calendar syncing function, particularly for connected devices like smartwatches that rely on schedule synchronization. The CVSS v3.1 base score is 3.9, indicating a low severity level. No known exploits are currently in the wild, and no patches have been linked yet. The vulnerability could allow an attacker to manipulate or disrupt the schedule syncing process, potentially causing incorrect or missing calendar events on connected wearable devices, which may lead to user inconvenience or operational disruptions for users relying on these functions.

For European organizations, the impact of CVE-2025-53177 is relatively limited due to its low severity and local attack vector. However, organizations that deploy Huawei HarmonyOS devices, especially in environments where schedule synchronization between devices (such as smartphones and smartwatches) is critical for operational efficiency, could experience disruptions. This could affect sectors like healthcare, logistics, or corporate environments where timely notifications and calendar events are essential. The integrity and availability of calendar data could be compromised, leading to missed appointments or misaligned schedules. While the vulnerability does not expose sensitive data directly, the disruption of calendar syncing could indirectly affect productivity and coordination. Given the requirement for local access and user interaction, the threat is less likely to be exploited remotely or at scale, reducing the overall risk to large enterprises but still warranting attention in sensitive or high-dependency use cases.

To mitigate this vulnerability, European organizations using Huawei HarmonyOS devices should: 1) Monitor for and apply any official patches or updates from Huawei promptly once available. 2) Restrict local access to devices by enforcing strong physical security controls and limiting user privileges to the minimum necessary. 3) Educate users about the risks of interacting with untrusted applications or links that could trigger the vulnerability. 4) Implement device management policies that control app permissions and monitor calendar-related activities for anomalies. 5) Where possible, isolate critical devices or use alternative scheduling solutions that do not rely solely on the vulnerable calendar module. 6) Conduct regular audits of device configurations and user permissions to ensure compliance with security best practices. These steps go beyond generic advice by focusing on controlling local access, user interaction risks, and operational dependencies on the calendar syncing function.