CVE-2025-57707 is a vulnerability classified under CWE-96 (Improper Neutralization of Directives in Dynamically Evaluated Code), affecting QNAP Systems Inc.'s File Station 5 product, specifically versions 5.5.x. The flaw arises from improper sanitization of directives in statically saved code, enabling a form of static code injection. An attacker who has already obtained a valid user account on the affected system can exploit this vulnerability to access restricted files or data that should otherwise be inaccessible. The attack vector is remote network access, with low attack complexity and no need for elevated privileges beyond a user account. User interaction is required, indicating that the attacker must trigger some action, possibly via the File Station interface or related functionality. The vulnerability does not allow for code execution or privilege escalation, limiting its impact primarily to confidentiality breaches of restricted files. The vendor has addressed the issue in File Station 5 version 5.5.6.5166 and later. The CVSS 4.0 base score is 1.1, indicating low severity due to limited impact and exploitation scope. No known exploits have been reported in the wild, suggesting the threat is currently theoretical but should be mitigated proactively. The vulnerability highlights the importance of proper input validation and sanitization in web-based file management systems, especially those exposed to network access and used in enterprise environments.

For European organizations, the primary impact of CVE-2025-57707 lies in potential unauthorized access to sensitive or restricted files stored on QNAP NAS devices running vulnerable versions of File Station 5. This could lead to confidentiality breaches, especially if the compromised user accounts have access to critical business data, intellectual property, or personal data protected under GDPR. While the vulnerability does not allow privilege escalation or remote code execution, the ability to access restricted files could facilitate further attacks or data leaks. Organizations relying heavily on QNAP NAS for file sharing and storage, particularly in sectors like finance, healthcare, and government, may face increased risk. The low CVSS score and absence of known exploits reduce immediate urgency but do not eliminate the threat, especially considering the potential for targeted attacks leveraging compromised user credentials. Failure to patch could also impact compliance with data protection regulations due to unauthorized data exposure.

European organizations should prioritize upgrading QNAP File Station 5 to version 5.5.6.5166 or later, where the vulnerability is fixed. In addition, organizations should enforce strong user account security policies, including multi-factor authentication (MFA) to reduce the risk of account compromise. Regularly audit user permissions to ensure least privilege principles are applied, limiting access to sensitive files only to necessary users. Network segmentation and firewall rules should restrict access to NAS management interfaces to trusted internal networks or VPNs. Monitoring and logging access to File Station can help detect suspicious activities indicative of exploitation attempts. Organizations should also educate users about phishing and social engineering risks that could lead to account compromise. Finally, ensure that backup and recovery procedures are robust to mitigate potential data exposure consequences.