CVE-2025-54623 is a medium-severity vulnerability identified in Huawei's HarmonyOS versions 5.1.0 and 5.0.1. The vulnerability is classified as CWE-680, which refers to an Integer Overflow to Buffer Overflow issue. Specifically, it exists in the devicemanager module of HarmonyOS. An integer overflow occurs when an arithmetic operation attempts to create a numeric value that is outside the range that can be represented with a given number of bits. This overflow can lead to a buffer overflow, where a program writes data beyond the boundaries of allocated memory buffers. In this case, the vulnerability manifests as an out-of-bounds read, which can cause the system to access memory locations outside the intended buffer. The CVSS v3.1 base score is 6.3, indicating a medium severity level. The vector string (AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L) shows that the attack vector requires adjacent network access (AV:A), has low attack complexity (AC:L), requires no privileges (PR:N), no user interaction (UI:N), and affects confidentiality, integrity, and availability to a low extent (C:L/I:L/A:L). Successful exploitation could lead to partial compromise of confidentiality and integrity, and impact system availability, potentially causing crashes or denial of service. No known exploits are currently in the wild, and no patches have been linked yet. The vulnerability's presence in the devicemanager module suggests it could affect device management operations, potentially impacting system stability and reliability.

For European organizations, the impact of this vulnerability depends largely on the extent of HarmonyOS deployment within their environments. HarmonyOS is primarily used in Huawei devices, including smartphones, IoT devices, and other smart hardware. Organizations using Huawei devices for critical operations, device management, or IoT infrastructure could face risks of service disruption due to availability impacts. The out-of-bounds read leading to buffer overflow could cause system crashes or denial of service, affecting operational continuity. Additionally, the partial compromise of confidentiality and integrity could expose sensitive device management data or allow manipulation of device states, which may have downstream effects on network security and data protection compliance. Given the medium severity and the lack of required privileges or user interaction, the vulnerability could be exploited by attackers with adjacent network access, such as within corporate LANs or via compromised devices on the same network segment. This elevates the risk in environments with dense Huawei device usage or interconnected IoT ecosystems. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits post-disclosure. European organizations must consider the potential for targeted attacks exploiting this vulnerability to disrupt services or gain footholds in device management systems.

1. Immediate inventory and assessment: Identify all Huawei devices running HarmonyOS versions 5.0.1 and 5.1.0 within the organization, focusing on those involved in device management and critical operations. 2. Network segmentation: Restrict network access to Huawei devices, especially the devicemanager module, limiting adjacent network exposure. Use VLANs and firewall rules to isolate these devices from untrusted or less secure network segments. 3. Monitor network traffic: Deploy intrusion detection/prevention systems (IDS/IPS) to detect anomalous traffic patterns indicative of exploitation attempts targeting the devicemanager module. 4. Apply vendor updates promptly: Although no patches are currently linked, maintain close monitoring of Huawei security advisories and apply updates as soon as patches become available. 5. Implement strict access controls: Enforce least privilege principles on device management interfaces and restrict administrative access to trusted personnel and systems. 6. Conduct penetration testing and vulnerability scanning: Regularly test the environment for signs of exploitation or presence of similar vulnerabilities. 7. Incident response preparedness: Develop and rehearse response plans for potential denial-of-service or compromise scenarios involving Huawei devices. 8. Collaborate with Huawei support: Engage with Huawei for guidance, early patch access, and coordinated vulnerability disclosure handling.