CVE-2025-14187 identifies a critical buffer overflow vulnerability in the UGREEN DH2100+ NAS device firmware version 5.3.0.251125. The vulnerability exists in the function handler_file_backup_create, which processes requests to the /v1/file/backup/create endpoint within the nas_svr component. Specifically, the flaw is triggered by malicious manipulation of the 'path' argument, which is not properly validated or bounded, leading to a buffer overflow condition. This overflow can be exploited remotely over the network without requiring user interaction or elevated privileges, making it highly accessible to attackers. The impact of this overflow includes potential remote code execution, allowing attackers to execute arbitrary code with high privileges, compromise device integrity, exfiltrate or corrupt data, or cause denial of service by crashing the device. The exploit code has been publicly released, increasing the likelihood of exploitation in the wild. Despite early notification, the vendor has not issued a patch or response, leaving affected devices vulnerable. 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 network attack vector, low attack complexity, no user interaction, but requiring high privileges, with high impact on confidentiality, integrity, and availability. This suggests that attackers with some level of access (e.g., authenticated users or internal network access) can exploit the vulnerability remotely. The lack of vendor patch necessitates immediate defensive measures by organizations using this device.

For European organizations, the impact of CVE-2025-14187 is significant due to the critical role NAS devices like the UGREEN DH2100+ play in data storage, backup, and file sharing. Successful exploitation could lead to unauthorized remote code execution, enabling attackers to gain control over the device and potentially pivot into internal networks. This threatens confidentiality through data theft, integrity via data manipulation or destruction, and availability by causing device crashes or persistent denial of service. Sectors such as finance, healthcare, manufacturing, and government agencies that rely on secure and reliable NAS infrastructure are particularly vulnerable. The public availability of exploit code increases the risk of opportunistic attacks and targeted intrusions. Additionally, the vendor's lack of response and absence of patches prolong exposure, forcing organizations to rely on compensating controls. The vulnerability could also be leveraged in supply chain attacks or ransomware campaigns, amplifying its impact across European enterprises.

Given the absence of an official patch from UGREEN, European organizations should implement layered mitigation strategies. First, restrict network access to the /v1/file/backup/create endpoint by implementing strict firewall rules and network segmentation to limit exposure to trusted hosts only. Deploy intrusion detection and prevention systems (IDS/IPS) with signatures or heuristics to detect anomalous requests targeting the vulnerable API. Enforce strong authentication and access controls on the NAS device to reduce the risk of attackers gaining the required privileges to exploit the vulnerability. Monitor logs and network traffic for unusual activity indicative of exploitation attempts. Where possible, disable or restrict the backup creation functionality if not essential. Consider deploying virtual patching via web application firewalls (WAF) to filter malicious payloads targeting the 'path' parameter. Maintain regular backups of critical data stored on the device to enable recovery in case of compromise. Finally, engage with UGREEN support channels to demand timely patching and stay informed about any future updates or advisories.