CVE-2025-54630 is a heap-based buffer overflow vulnerability identified in Huawei's HarmonyOS, specifically within the DFA (Deterministic Finite Automaton) module. The root cause of this vulnerability is insufficient data length verification, which allows an attacker to provide input data that exceeds the allocated buffer size on the heap. This type of vulnerability (CWE-122) can lead to memory corruption, potentially allowing an attacker to overwrite critical data structures, cause application crashes, or execute arbitrary code. However, the CVSS vector indicates that the attack vector is physical (AV:P), meaning the attacker must have physical access to the device to exploit this vulnerability. The attack complexity is low (AC:L), no privileges or user interaction are required (PR:N, UI:N), and the scope is unchanged (S:U). The impact on confidentiality, integrity, and availability is rated high (C:H/I:H/A:H), indicating that a successful exploit could fully compromise the affected system. The affected versions are HarmonyOS 4.3.0 and 5.0.1. As of the published date (August 6, 2025), there are no known exploits in the wild and no patches have been linked yet. The vulnerability primarily threatens system availability but given the high impact ratings on confidentiality and integrity, it could potentially be leveraged for broader system compromise. The requirement for physical access significantly limits remote exploitation but does not eliminate risk in environments where devices are accessible to attackers physically.

For European organizations, the impact of CVE-2025-54630 depends largely on the deployment of Huawei HarmonyOS devices within their infrastructure. HarmonyOS is primarily used in Huawei's IoT devices, smartphones, and embedded systems. Organizations using Huawei hardware running affected versions could face risks of device crashes or denial of service, impacting operational continuity. The high impact on confidentiality and integrity suggests that sensitive data on these devices could be at risk if exploited. Critical infrastructure or industrial environments using HarmonyOS-powered IoT devices may experience disruptions, potentially affecting service availability. The physical access requirement reduces the likelihood of remote attacks but insider threats or attackers with physical proximity could exploit this vulnerability. This is particularly relevant for sectors with less controlled physical access, such as manufacturing floors, logistics, or public-facing kiosks. Additionally, given Huawei's significant market presence in some European countries, the vulnerability could affect a broad range of devices, increasing the attack surface. The absence of known exploits currently provides a window for proactive mitigation before exploitation becomes widespread.

1. Immediate physical security enhancements: Restrict physical access to devices running HarmonyOS, especially in sensitive or critical environments, to prevent exploitation. 2. Monitor for firmware or OS updates from Huawei: Although no patches are currently linked, organizations should prioritize applying official security updates as soon as they become available. 3. Inventory and audit: Identify all Huawei HarmonyOS devices in use, including IoT and embedded systems, and verify their OS versions to assess exposure. 4. Network segmentation: Isolate HarmonyOS devices on separate network segments to limit potential lateral movement if a device is compromised. 5. Implement device hardening: Disable unnecessary services and interfaces on HarmonyOS devices to reduce attack vectors. 6. Incident response readiness: Prepare for potential exploitation scenarios by establishing monitoring for unusual device behavior or crashes indicative of buffer overflow exploitation. 7. Engage with Huawei support: Request detailed guidance and timelines for patches or mitigations specific to this vulnerability. 8. Consider alternative devices or OS versions where feasible, especially in high-risk environments, until the vulnerability is addressed.