CVE-2025-59389 is an SQL injection vulnerability classified under CWE-89 affecting QNAP Systems Inc.'s Hyper Data Protector software, specifically versions 2.2.x. SQL injection vulnerabilities occur when untrusted input is improperly sanitized, allowing attackers to manipulate backend database queries. In this case, remote attackers can exploit the flaw without requiring authentication or user interaction, enabling them to execute arbitrary code or commands on the affected system. The vulnerability's CVSS 4.0 score is 8.1, reflecting its high severity due to network attack vector, low attack complexity, no privileges or user interaction needed, and high impact on confidentiality, integrity, and availability. The vulnerability was reserved in September 2025 and published in January 2026. Although no known exploits have been reported in the wild yet, the potential for severe damage is significant, including data theft, system compromise, and disruption of backup and recovery operations. The vendor has released a fix in Hyper Data Protector version 2.2.4.1 and later, which addresses the input validation issues causing the SQL injection. Organizations running affected versions should upgrade promptly to mitigate exploitation risks.

For European organizations, the impact of this vulnerability can be substantial. Hyper Data Protector is used for backup and disaster recovery, making it a critical component in data protection strategies. Successful exploitation could lead to unauthorized access to sensitive backup data, manipulation or deletion of backups, and potential lateral movement within networks. This compromises data confidentiality and integrity, and could disrupt availability of backup services, hindering recovery efforts after incidents. Sectors such as finance, healthcare, and government, which rely heavily on data integrity and availability, are at heightened risk. Additionally, the remote and unauthenticated nature of the exploit increases the likelihood of attacks originating from external threat actors, including cybercriminals and state-sponsored groups targeting European infrastructure. The absence of known exploits in the wild currently provides a window for proactive defense, but the high severity score demands urgent attention.

European organizations should immediately verify their Hyper Data Protector version and upgrade to version 2.2.4.1 or later to remediate the vulnerability. In addition to patching, organizations should implement network segmentation to limit exposure of backup systems to untrusted networks. Employing Web Application Firewalls (WAFs) with SQL injection detection rules can provide an additional layer of defense. Regularly audit and monitor logs for unusual database queries or commands that could indicate exploitation attempts. Restrict database permissions used by Hyper Data Protector to the minimum necessary to reduce potential damage from exploitation. Conduct penetration testing focused on SQL injection vectors in backup management systems. Finally, maintain up-to-date incident response plans that include scenarios involving backup system compromise to ensure rapid containment and recovery.