CVE-2025-29871 is an out-of-bounds read vulnerability classified under CWE-125 affecting QNAP Systems Inc.'s File Station 5 product, specifically versions 5.5.x prior to 5.5.6.4847. File Station 5 is a file management application commonly used on QNAP NAS devices to facilitate file sharing and management. The vulnerability allows a local attacker who has already obtained administrator-level access to exploit an out-of-bounds read flaw to access secret or sensitive data that should otherwise be protected. This vulnerability does not allow privilege escalation or remote exploitation directly but requires the attacker to have high privileges (administrator) and some user interaction. The CVSS v4.0 base score is 2.4, indicating a low severity primarily due to the requirement of local privileged access and user interaction, and limited impact on confidentiality, integrity, and availability. The vulnerability has been fixed in File Station 5 version 5.5.6.4847 and later. No known exploits are reported in the wild at this time. The flaw arises from improper bounds checking in memory reads, which can lead to leakage of sensitive information from memory buffers. This can potentially expose confidential data stored or processed by the File Station application, but only to an attacker with already elevated privileges on the device.

For European organizations using QNAP NAS devices with File Station 5 versions 5.5.x prior to 5.5.6.4847, this vulnerability poses a limited but tangible risk. Since exploitation requires local administrator access, the primary impact is on confidentiality if an insider threat or attacker who has compromised admin credentials attempts to extract sensitive data from the NAS device memory. This could include sensitive corporate documents, credentials, or other confidential files managed via File Station. The vulnerability does not allow remote exploitation or privilege escalation, so the attack surface is limited to already compromised systems. However, given the widespread use of QNAP NAS devices in small and medium enterprises across Europe for file storage and sharing, the vulnerability could be leveraged as part of a multi-stage attack or insider threat scenario. The low CVSS score reflects the limited scope and difficulty of exploitation, but organizations should not ignore the risk of data leakage in environments where sensitive data is stored on vulnerable versions. The lack of known exploits in the wild reduces immediate urgency but patching is recommended to prevent future exploitation.

1. Immediately upgrade all QNAP File Station 5 installations to version 5.5.6.4847 or later to apply the official patch that fixes the out-of-bounds read vulnerability. 2. Restrict administrator access to NAS devices strictly on a need-to-know basis and enforce strong authentication mechanisms such as multi-factor authentication to reduce the risk of credential compromise. 3. Monitor and audit administrator activities on NAS devices to detect any unusual access patterns or attempts to access sensitive data. 4. Implement network segmentation to isolate NAS devices from general user networks, limiting local access to trusted administrators only. 5. Regularly review and update NAS device firmware and software to ensure all security patches are applied promptly. 6. Conduct internal security awareness training to reduce insider threat risks and encourage reporting of suspicious activities. 7. Employ endpoint detection and response (EDR) solutions on systems that access NAS devices to detect potential lateral movement or privilege misuse.