CVE-2025-14187 identifies a critical buffer overflow vulnerability in the UGREEN DH2100+ network-attached storage (NAS) device firmware versions up to 5.3.0.251125. The vulnerability resides in the function handler_file_backup_create, which processes requests to the /v1/file/backup/create REST API endpoint within the nas_svr component. Specifically, the flaw arises from improper handling and validation of the 'path' argument, allowing an attacker to craft a malicious request that overflows an internal buffer. This overflow can corrupt memory, potentially enabling remote code execution or causing a denial of service. The attack vector is network-based, requiring no user interaction or prior authentication, which significantly increases the attack surface. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P) indicates a high impact on confidentiality, integrity, and availability, with partial requirements for privileges (PR:H) but no user interaction. While no active exploitation has been observed in the wild, publicly available exploit code increases the likelihood of future attacks. The vulnerability affects a widely used NAS device model, often deployed in enterprise and SMB environments for file storage and backup, making it a critical concern for data security and operational continuity.

For European organizations, the exploitation of CVE-2025-14187 could lead to severe consequences including unauthorized access to sensitive data, disruption of backup and file storage services, and potential lateral movement within networks. Given the device's role in data backup and storage, a successful attack could compromise data integrity and availability, resulting in data loss or ransomware-like scenarios. The remote exploitability without user interaction or authentication amplifies the risk, especially in environments where these NAS devices are exposed to untrusted networks or insufficiently segmented. This could affect sectors relying heavily on data availability and confidentiality such as finance, healthcare, manufacturing, and public administration. Additionally, the presence of publicly available exploit code lowers the barrier for threat actors, increasing the urgency for mitigation. The impact extends beyond individual organizations to supply chains and critical infrastructure that depend on these devices for reliable data storage and backup.

European organizations should immediately verify if UGREEN DH2100+ devices are deployed within their infrastructure and identify affected firmware versions. Since no official patch links are provided, organizations should monitor UGREEN's official channels for firmware updates addressing this vulnerability and apply them promptly once available. In the interim, restrict network access to the NAS devices by implementing strict firewall rules and network segmentation to limit exposure of the /v1/file/backup/create endpoint to trusted internal networks only. Employ intrusion detection and prevention systems (IDS/IPS) to monitor and block suspicious requests targeting the vulnerable API. Conduct regular audits of device configurations and logs to detect anomalous activities. Additionally, consider disabling or restricting backup creation functionalities if not essential. Implement strong access controls and privilege management to minimize the impact of potential exploitation. Finally, maintain up-to-date asset inventories and vulnerability management processes to ensure timely response to emerging threats.